PR P: full async I/O top to bottom (item 19)

Every repository, service, Blazor page/dialog, and test now uses
async/await. Single atomic diff; the codebase does not compile in
intermediate states.

- BaseRepository: LoadListAsync/LoadAsync/SaveAsync return Task<T>;
  per-file locks use SemaphoreSlim so waiters can await; Save
  serialises to a MemoryStream sync (XmlSerializer has no async
  form), then File.WriteAllBytesAsync + sync File.Move.
- RepositoryCache.GetOrLoadAsync takes a Func<Task<List<T>>>.
- All 7 repository interfaces + implementations async.
- All service interfaces + implementations async (except vendor
  IFxService and stateless IFxConverter / SettingsService).
- Every Blazor OnInitializedAsync switches to await base.
- Test suite fully async, 42 tests pass.

AccountRepository.EnsureAccountsFile keeps two .GetAwaiter().GetResult()
bridges because it runs from the constructor.

Null-render guard follow-up (folded in):
Blazor now renders the component once with fields at their initial
values while OnInitializedAsync awaits — so fields declared `= null!`
are actually null on that first render and things like
`accounts.GroupBy(...)` throw ArgumentNullException. Fixed across
Transactions, BalanceReport, BalanceSheetReport, ProfitLossReport,
DetailReport, Assets, Spendings, SpendingsOverTime, TransactionDialog,
TransactionSplitDialog, and BookingRuleDialog:
- Collection fields initialise to [] so first-render loops are empty.
- Single-object data fields become nullable; the razor wraps
  consumption in `@if (field is null) { <p>Lädt…</p> return; }`.
- <PlotlyChart> guarded behind a null check on config/layout/data so
  Plotly.Blazor's @bind doesn't see nulls.
- Header/footer strings initialise to "" instead of null!.

Architectural hygiene on a single-user local Blazor Server app: the
observed win is one File.ReadAllBytesAsync and one
File.WriteAllBytesAsync per Load/Save, and after PR D each file is
loaded at most once per SignalR circuit.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

IMPROVEMENT_PLAN.md

@@ -101,7 +101,7 @@ Analysis and phased plan produced 2026-07-02. See conversation history for full
 - **PR D** — Phase 2 item 9: per-request unit of work / cache. Split off from PR C because it is invasive enough to warrant its own review.
 - **PR E** — Phase 3 item 22: ChartService cleanup. Promoted ahead of async because it fixes an active correctness bug — `GetAccountExpensesPerMonth(accountId, year)` was mutating `ISettingsService` on the singleton to hop years, with the year parameter always hardcoded to `DateTime.Now.Year`, so the Spendings-over-time chart discarded the user's header year selection.
 - **PR F** — Phase 3 item 21: precomputed dictionaries in `ViewService` to eliminate O(N·M) `Single(...)` scans and per-account transaction filtering.
-- **Item 19 (async I/O)** — deferred. After PR D, each XML file is loaded at most once per SignalR circuit, and this app is single-user local Blazor Server. Converting every repository/service method to async would touch ~40 files for negligible user-visible benefit and real regression risk. Revisit if the app is ever hosted for multiple concurrent users.
+- **Item 19 (async I/O)** — landed as PR P after being explicitly requested. See PR P entry below.
 - **PR G** — Phase 4 items 23 + 24: `Schaad.Accounting.Tests` xUnit + NSubstitute + Shouldly project. Adopts the `xxxTestShould.DoThisWhenThat` naming convention with Shouldly assertions (no xUnit `Assert.*`). Covers `ViewService`, `TransactionRepository`, `Formatting`, `RepositoryCache`, `AccountRepository`, `ChartService`, and `FileService.GetTransactionListCsv` — 38 tests locking in the earlier PRs' behavior. Note: originally shipped as three separate commits (initial project, expanded coverage, Shouldly + naming conversion) and later squashed into one commit at the user's request.
 - **PR H** — Phase 2 item 18 (first slice): add `ILogger<FileService>` to `FileService.ImportAccountStatementFile` so bank-statement imports emit `Information` for the file being processed and each account's import count, `Warning` when an account is skipped because it belongs to a different mandator, and `Error` when the vendor parser reports a failure. Rest of the logging (BaseRepository save failures, MatchOpenBankTransactions summary) tracked as a follow-up because it requires threading loggers through all seven repositories.
 - **PR I** — Phase 2 item 12: move the service interfaces (`IViewService`, `IFileService`, `IChartService`) from `Schaad.Accounting.Common` into `Schaad.Accounting.Services/Interfaces/`. Namespaces are unchanged (`Schaad.Accounting.Interfaces`), so no consumer needs a `using` update. Drops the `Schaad.Finance.Api` `<Reference>` from `Common.csproj` — Common is now vendor-free and matches its documented role as the "shared models, DTOs, interfaces" layer.
@@ -111,3 +111,4 @@ Analysis and phased plan produced 2026-07-02. See conversation history for full
 - **PR M** — Phase 2 item 18 (final slice): add `ILogger<ViewService>` and log a match-count summary from `MatchOpenBankTransactions` (`"Matched {Matched} of {Total} open bank transactions"`). Completes item 18 — statement imports (PR H), repository save failures (PR J), and match runs now all emit structured logs. Also removes a dead `ISettingsService` injection from `Home.razor.cs` (declared with `[Inject]` but never used anywhere in the file).
 - **PR N** — Small polish pass covering three long-noted rough edges from the original analysis: `ClassIds` becomes a `static class` (was instantiable); `Home.razor.cs` loses the redundant `loaded` guard in `OnInitializedAsync` (Blazor already runs that lifecycle hook once per component instance); the hardcoded `mandator = "Claudio Schaad"` in `SettingsService` moves to a `DefaultMandator` field on `SettingsDataset`, plumbed through `appsettings.Development.json`.
 - **PR O** — Phase 5 item 26 (partial): convert `BalanceDataset` and `BalanceSheetDataset` to positional records. Both were constructor-initialised value carriers with read-only usage. The rest of item 26 was descoped: the XML-serialised domain models (`Account`, `Transaction`, ...) need mutable public setters for `XmlSerializer`, and value-equality on mutable data is a footgun (hash changes on mutation); source-generated XML serialisers do not exist without switching file formats. `DataSerie` was already a record; `MessageDataset` has a real mutation method (`Add`) and stays a class; `AccountDataset` / `TransactionDataset` / `BookingRuleDataset` inherit from the mutable domain models and can't cleanly become records without a bigger refactor.
+- **PR P** — Phase 3 item 19: full async I/O top to bottom. `BaseRepository.LoadAsync/SaveAsync/LoadListAsync` return `Task<T>`; the per-file `lock (obj)` becomes `SemaphoreSlim` so it can be `await`-ed. `Save` serialises to a `MemoryStream` synchronously (XmlSerializer has no async form) then writes bytes with `File.WriteAllBytesAsync`; `File.Move` (atomic rename) has no async counterpart in .NET 9 and stays sync. Every repository interface + implementation, every service interface + implementation (except the vendor-owned `IFxService`), every Razor page/dialog `OnInitializedAsync`, and every test-file assertion becomes `async` / `await`. 51 files touched in one atomic diff — the codebase does not compile in intermediate states. `AccountRepository.EnsureAccountsFile` keeps two `.GetAwaiter().GetResult()` bridges because it runs from the constructor (constructors can't be async). The observed async payoff is one `File.ReadAllBytesAsync` and one `File.WriteAllBytesAsync` per Load/Save; after PR D each XML file is deserialised at most once per SignalR circuit, so on this single-user local Blazor Server app this is architectural-hygiene work, not a measurable perf win.

Schaad.Accounting.Common/Interfaces/IAccountRepository.cs

@@ -1,20 +1,21 @@
-using System.Collections.Generic;
+using System.Collections.Generic;
+using System.Threading.Tasks;
 using Schaad.Accounting.Models;
 
 namespace Schaad.Accounting.Interfaces
 {
     public interface IAccountRepository
     {
-        List<Account> GetAccountList();
+        Task<List<Account>> GetAccountListAsync();
 
-        void SaveAccount(Account account);
+        Task SaveAccountAsync(Account account);
 
-        Account GetAccount(string id);
+        Task<Account> GetAccountAsync(string id);
 
-        void DeleteAccount(string id);
+        Task DeleteAccountAsync(string id);
 
-        Account GetAccountForBankAccountNumber(string bankAccountNumber);
+        Task<Account> GetAccountForBankAccountNumberAsync(string bankAccountNumber);
 
-        void SaveBankAccountBalance(string bankAccountNumber, decimal accountBalance);
+        Task SaveBankAccountBalanceAsync(string bankAccountNumber, decimal accountBalance);
     }
 }

Schaad.Accounting.Common/Interfaces/IBankTransactionRepository.cs

@@ -1,4 +1,5 @@
-using System.Collections.Generic;
+using System.Collections.Generic;
+using System.Threading.Tasks;
 using Schaad.Accounting.Datasets;
 using Schaad.Accounting.Models;
 
@@ -6,10 +7,10 @@ namespace Schaad.Accounting.Interfaces
 {
     public interface IBankTransactionRepository
     {
-        List<BankTransaction> GetBankTransactionList();
+        Task<List<BankTransaction>> GetBankTransactionListAsync();
 
-        int SaveBankTransactionList(string bankAccountNumber, List<BankTransactionDataset> bankTransactions);
+        Task<int> SaveBankTransactionListAsync(string bankAccountNumber, List<BankTransactionDataset> bankTransactions);
 
-        BankTransaction GetBankTransaction(string id);
+        Task<BankTransaction> GetBankTransactionAsync(string id);
     }
 }

Schaad.Accounting.Common/Interfaces/IBookingRuleRepository.cs

@@ -1,15 +1,17 @@
-using System.Collections.Generic;
+using System.Collections.Generic;
+using System.Threading.Tasks;
 using Schaad.Accounting.Models;
 
 namespace Schaad.Accounting.Interfaces
 {
     public interface IBookingRuleRepository
     {
-        List<BookingRule> GetBookingRuleList();
+        Task<List<BookingRule>> GetBookingRuleListAsync();
 
-        void SaveBookingRule(BookingRule bookingRule);
+        Task SaveBookingRuleAsync(BookingRule bookingRule);
 
-        BookingRule GetBookingRule(string id);
+        Task<BookingRule> GetBookingRuleAsync(string id);
-        void DeleteBookingRule(string id);
+
+        Task DeleteBookingRuleAsync(string id);
     }
 }

Schaad.Accounting.Common/Interfaces/IBookingTextRepository.cs

@@ -1,16 +1,17 @@
-using System.Collections.Generic;
+using System.Collections.Generic;
+using System.Threading.Tasks;
 using Schaad.Accounting.Models;
 
 namespace Schaad.Accounting.Interfaces
 {
     public interface IBookingTextRepository
     {
-        List<BookingText> GetBookingTextList();
+        Task<List<BookingText>> GetBookingTextListAsync();
 
-        void SaveBookingText(BookingText bookingText);
+        Task SaveBookingTextAsync(BookingText bookingText);
 
-        BookingText GetBookingText(string id);
+        Task<BookingText> GetBookingTextAsync(string id);
 
-        void DeleteBookingText(string id);
+        Task DeleteBookingTextAsync(string id);
     }
 }

Schaad.Accounting.Common/Interfaces/ISplitPredefinitionRepository.cs

@@ -1,12 +1,13 @@
 using System.Collections.Generic;
+using System.Threading.Tasks;
 using Schaad.Accounting.Models;
 
 namespace Schaad.Accounting.Interfaces
 {
     public interface ISplitPredefinitionRepository
     {
-        List<SplitPredefinition> GetSplitPredefinitionList();
+        Task<List<SplitPredefinition>> GetSplitPredefinitionListAsync();
 
-        void SaveSplitPredefinition(SplitPredefinition splitPredefinition);
+        Task SaveSplitPredefinitionAsync(SplitPredefinition splitPredefinition);
     }
 }

Schaad.Accounting.Common/Interfaces/ISubclassRepository.cs

@@ -1,17 +1,18 @@
-using System.Collections.Generic;
+using System.Collections.Generic;
+using System.Threading.Tasks;
 using Schaad.Accounting.Models;
 
 namespace Schaad.Accounting.Interfaces
 {
     public interface ISubclassRepository
     {
-        List<SubClass> GetSubClassList();
+        Task<List<SubClass>> GetSubClassListAsync();
 
-        void SaveSubClass(SubClass subClass);
+        Task SaveSubClassAsync(SubClass subClass);
 
-        SubClass GetSubClass(string id);
+        Task<SubClass> GetSubClassAsync(string id);
 
-        void DeleteSubClass(string id);
+        Task DeleteSubClassAsync(string id);
 
         Dictionary<int, string> GetClasses();
 

Schaad.Accounting.Common/Interfaces/ITransactionRepository.cs

@@ -1,15 +1,17 @@
-using System.Collections.Generic;
+using System.Collections.Generic;
+using System.Threading.Tasks;
 using Schaad.Accounting.Models;
 
 namespace Schaad.Accounting.Interfaces
 {
     public interface ITransactionRepository
     {
-        List<Transaction> GetTransactionList();
+        Task<List<Transaction>> GetTransactionListAsync();
 
-        void SaveTransaction(Transaction transaction);
+        Task SaveTransactionAsync(Transaction transaction);
 
-        Transaction GetTransaction(string id);
+        Task<Transaction> GetTransactionAsync(string id);
-        void DeleteTransaction(string id);
+
+        Task DeleteTransactionAsync(string id);
     }
 }

Schaad.Accounting.Db/Repositories/AccountRepository.cs

@@ -1,7 +1,8 @@
-using System;
+using System;
 using System.Collections.Generic;
 using System.IO;
 using System.Linq;
+using System.Threading.Tasks;
 using Microsoft.Extensions.Logging;
 using Schaad.Accounting.Interfaces;
 using Schaad.Accounting.Models;
@@ -18,22 +19,16 @@ namespace Schaad.Accounting.Repositories
             EnsureAccountsFile();
         }
 
-        /// <summary>
+        public Task<List<Account>> GetAccountListAsync() => LoadListAsync<Account>(ACCOUNTS);
-        /// Load accounts
-        /// </summary>
-        public List<Account> GetAccountList() => LoadList<Account>(ACCOUNTS);
 
-        /// <summary>
+        public async Task SaveAccountAsync(Account account)
-        /// Save an account (insert/update)
-        /// </summary>
-        public void SaveAccount(Account account)
         {
             if (string.IsNullOrEmpty(account.Currency))
             {
                 account.Currency = "CHF";
             }
 
-            var accounts = GetAccountList();
+            var accounts = await GetAccountListAsync();
             var idx = accounts.FindIndex(a => a.Id == account.Id);
             if (idx >= 0)
             {
@@ -44,42 +39,33 @@ namespace Schaad.Accounting.Repositories
                 account.Id = Guid.NewGuid().ToString();
                 accounts.Add(account);
             }
-            Save(accounts, ACCOUNTS);
+            await SaveAsync(accounts, ACCOUNTS);
         }
 
-        /// <summary>
+        public async Task<Account> GetAccountAsync(string id)
-        /// Get account
-        /// </summary>
-        public Account GetAccount(string id)
         {
-            var accounts = GetAccountList();
+            var accounts = await GetAccountListAsync();
             return accounts.FirstOrDefault(t => t.Id == id);
         }
 
-        /// <summary>
+        public async Task DeleteAccountAsync(string id)
-        /// Delete account
-        /// </summary>
-        public void DeleteAccount(string id)
         {
-            var accounts = GetAccountList();
+            var accounts = await GetAccountListAsync();
             accounts.RemoveAll(t => t.Id == id);
-            Save(accounts, ACCOUNTS);
+            await SaveAsync(accounts, ACCOUNTS);
         }
 
-        /// <summary>
+        public async Task<Account> GetAccountForBankAccountNumberAsync(string bankAccountNumber)
-        /// Get account
-        /// </summary>
-        public Account GetAccountForBankAccountNumber(string bankAccountNumber)
         {
-            var accounts = GetAccountList();
+            var accounts = await GetAccountListAsync();
             return accounts.SingleOrDefault(t => t.BankAccountNumber == bankAccountNumber);
         }
 
-        public void SaveBankAccountBalance(string bankAccountNumber, decimal accountBalance)
+        public async Task SaveBankAccountBalanceAsync(string bankAccountNumber, decimal accountBalance)
         {
-            var account = GetAccountForBankAccountNumber(bankAccountNumber);
+            var account = await GetAccountForBankAccountNumberAsync(bankAccountNumber);
             account.LastBankBalance = accountBalance;
-            SaveAccount(account);
+            await SaveAccountAsync(account);
         }
 
         private void EnsureAccountsFile()
@@ -98,7 +84,9 @@ namespace Schaad.Accounting.Repositories
 
             // Year rollover: seed start balances from the previous year's closing values.
             // Bank accounts start at the last known bank balance; cash accounts start at zero.
-            var accounts = GetAccountList();
+            // Uses the sync GetAwaiter().GetResult() bridge because this runs from the
+            // constructor; the file was just copied so the underlying I/O is local.
+            var accounts = GetAccountListAsync().GetAwaiter().GetResult();
             var modified = false;
             foreach (var account in accounts.Where(a => a.Class == ClassIds.Activa))
             {
@@ -115,7 +103,7 @@ namespace Schaad.Accounting.Repositories
             }
             if (modified)
             {
-                Save(accounts, ACCOUNTS);
+                SaveAsync(accounts, ACCOUNTS).GetAwaiter().GetResult();
             }
         }
     }

Schaad.Accounting.Db/Repositories/BankTransactionRepository.cs

@@ -1,5 +1,6 @@
-using System.Collections.Generic;
+using System.Collections.Generic;
 using System.Linq;
+using System.Threading.Tasks;
 using Microsoft.Extensions.Logging;
 using Schaad.Accounting.Datasets;
 using Schaad.Accounting.Interfaces;
@@ -16,18 +17,15 @@ namespace Schaad.Accounting.Repositories
         {
         }
 
-        /// <summary>
+        public Task<List<BankTransaction>> GetBankTransactionListAsync() => LoadListAsync<BankTransaction>(BANK_TRANSACTIONS);
-        /// Load bank transactions
-        /// </summary>
-        public List<BankTransaction> GetBankTransactionList() => LoadList<BankTransaction>(BANK_TRANSACTIONS);
 
         /// <summary>
         /// Save new bank transactions, ignore existing ones (no update)
         /// </summary>
-        public int SaveBankTransactionList(string bankAccountNumber, List<BankTransactionDataset> bankTransactions)
+        public async Task<int> SaveBankTransactionListAsync(string bankAccountNumber, List<BankTransactionDataset> bankTransactions)
         {
             var count = 0;
-            var transactions = GetBankTransactionList();
+            var transactions = await GetBankTransactionListAsync();
             foreach (var bankTrx in bankTransactions)
             {
                 var transaction = transactions.FirstOrDefault(t => t.Id == bankTrx.Id);
@@ -48,16 +46,13 @@ namespace Schaad.Accounting.Repositories
                     count++;
                 }
             }
-            Save(transactions, BANK_TRANSACTIONS);
+            await SaveAsync(transactions, BANK_TRANSACTIONS);
             return count;
         }
 
-        /// <summary>
+        public async Task<BankTransaction> GetBankTransactionAsync(string id)
-        /// Get bank transaction
-        /// </summary>
-        public BankTransaction GetBankTransaction(string id)
         {
-            var transactions = GetBankTransactionList();
+            var transactions = await GetBankTransactionListAsync();
             return transactions.FirstOrDefault(t => t.Id == id);
         }
     }

Schaad.Accounting.Db/Repositories/BaseRepository.cs

@@ -1,8 +1,10 @@
-using System;
+using System;
 using System.Collections.Concurrent;
 using System.Collections.Generic;
 using System.IO;
 using System.Text;
+using System.Threading;
+using System.Threading.Tasks;
 using System.Xml;
 using System.Xml.Serialization;
 using Microsoft.Extensions.Logging;
@@ -12,9 +14,9 @@ namespace Schaad.Accounting.Repositories
 {
     public abstract class BaseRepository
     {
-        // One lock per absolute file path so concurrent Save+Save and Save+Load are serialized
+        // One semaphore per absolute file path so concurrent SaveAsync+SaveAsync and
-        // and can't observe a half-written file.
+        // SaveAsync+LoadAsync are serialized and can't observe a half-written file.
-        private static readonly ConcurrentDictionary<string, object> FileLocks =
+        private static readonly ConcurrentDictionary<string, SemaphoreSlim> FileLocks =
             new(StringComparer.OrdinalIgnoreCase);
 
         protected readonly ISettingsService settingsService;
@@ -28,10 +30,17 @@ namespace Schaad.Accounting.Repositories
             this.logger = logger;
         }
 
+        /// <summary>
+        /// Copies fileName from last year's directory to the current year's directory when the
+        /// current year doesn't have it yet. Kept synchronous because it runs from repository
+        /// constructors; File.Copy has no async equivalent in .NET 9 either way.
+        /// </summary>
         protected void EnsureFileExists(string fileName)
         {
             string filePath = Path.Combine(settingsService.GetDbPath(), fileName);
-            lock (GetLock(filePath))
+            var semaphore = GetLock(filePath);
+            semaphore.Wait();
+            try
             {
                 if (File.Exists(filePath) == false)
                 {
@@ -42,16 +51,20 @@ namespace Schaad.Accounting.Repositories
                     }
                 }
             }
+            finally
+            {
+                semaphore.Release();
+            }
         }
 
         /// <summary>
         /// Load a list, cached per scope. First call reads the XML file; subsequent calls in
-        /// the same scope return the cached list. <see cref="Save"/> invalidates the entry.
+        /// the same scope return the cached list. <see cref="SaveAsync"/> invalidates the entry.
         /// </summary>
-        protected List<T> LoadList<T>(string fileName)
+        protected Task<List<T>> LoadListAsync<T>(string fileName)
         {
             var filePath = Path.Combine(settingsService.GetDbPath(), fileName);
-            return cache.GetOrLoad(filePath, () => Load<List<T>>(fileName) ?? new List<T>());
+            return cache.GetOrLoadAsync(filePath, async () => await LoadAsync<List<T>>(fileName) ?? new List<T>());
         }
 
         /// <summary>
@@ -59,12 +72,14 @@ namespace Schaad.Accounting.Repositories
         /// renames it, so a crash mid-write leaves the previous file intact. Invalidates
         /// the corresponding cache entry.
         /// </summary>
-        protected void Save<T>(T obj, string fileName)
+        protected async Task SaveAsync<T>(T obj, string fileName)
         {
             var filePath = Path.Combine(settingsService.GetDbPath(), fileName);
             var tmpPath = filePath + ".tmp";
 
-            lock (GetLock(filePath))
+            var semaphore = GetLock(filePath);
+            await semaphore.WaitAsync();
+            try
             {
                 var settings = new XmlWriterSettings
                 {
@@ -74,12 +89,16 @@ namespace Schaad.Accounting.Repositories
 
                 try
                 {
-                    using (var writer = XmlWriter.Create(tmpPath, settings))
+                    // XmlSerializer is synchronous — serialize to memory, then write async.
+                    using var memory = new MemoryStream();
+                    using (var writer = XmlWriter.Create(memory, settings))
                     {
                         var serializer = new XmlSerializer(typeof(T));
                         serializer.Serialize(writer, obj);
                     }
+                    await File.WriteAllBytesAsync(tmpPath, memory.ToArray());
 
+                    // File.Move has no async form in .NET 9.
                     File.Move(tmpPath, filePath, overwrite: true);
                 }
                 catch (Exception ex)
@@ -92,34 +111,43 @@ namespace Schaad.Accounting.Repositories
                     throw;
                 }
             }
+            finally
+            {
+                semaphore.Release();
+            }
 
             cache.Invalidate(filePath);
         }
 
         /// <summary>
         /// Load an object from an xml file (uncached; used for one-off reads such as file
-        /// existence bootstrapping). Prefer <see cref="LoadList{T}"/> for repository reads.
+        /// existence bootstrapping). Prefer <see cref="LoadListAsync{T}"/> for repository reads.
         /// </summary>
-        protected T Load<T>(string fileName)
+        protected async Task<T> LoadAsync<T>(string fileName)
         {
             var filePath = Path.Combine(settingsService.GetDbPath(), fileName);
 
-            lock (GetLock(filePath))
+            var semaphore = GetLock(filePath);
+            await semaphore.WaitAsync();
+            try
             {
                 if (File.Exists(filePath) == false)
                 {
                     return default(T);
                 }
 
-                using (XmlReader reader = XmlReader.Create(filePath))
+                var bytes = await File.ReadAllBytesAsync(filePath);
-                {
+                using var memory = new MemoryStream(bytes);
-                    var serializer = new XmlSerializer(typeof(T));
+                var serializer = new XmlSerializer(typeof(T));
-                    return (T)serializer.Deserialize(reader);
+                return (T)serializer.Deserialize(memory);
-                }
+            }
+            finally
+            {
+                semaphore.Release();
             }
         }
 
-        private static object GetLock(string filePath)
+        private static SemaphoreSlim GetLock(string filePath)
-            => FileLocks.GetOrAdd(filePath, _ => new object());
+            => FileLocks.GetOrAdd(filePath, _ => new SemaphoreSlim(1, 1));
     }
 }

Schaad.Accounting.Db/Repositories/BookingRuleRepository.cs

@@ -1,6 +1,7 @@
-using System;
+using System;
 using System.Collections.Generic;
 using System.Linq;
+using System.Threading.Tasks;
 using Microsoft.Extensions.Logging;
 using Schaad.Accounting.Interfaces;
 using Schaad.Accounting.Models;
@@ -17,17 +18,11 @@ namespace Schaad.Accounting.Repositories
             EnsureFileExists(BOOKING_RULES);
         }
 
-        /// <summary>
+        public Task<List<BookingRule>> GetBookingRuleListAsync() => LoadListAsync<BookingRule>(BOOKING_RULES);
-        /// Load booking rules
-        /// </summary>
-        public List<BookingRule> GetBookingRuleList() => LoadList<BookingRule>(BOOKING_RULES);
 
-        /// <summary>
+        public async Task SaveBookingRuleAsync(BookingRule bookingRule)
-        /// Save a booking rule (insert/update)
-        /// </summary>
-        public void SaveBookingRule(BookingRule bookingRule)
         {
-            var bookingRules = GetBookingRuleList();
+            var bookingRules = await GetBookingRuleListAsync();
             var idx = bookingRules.FindIndex(r => r.Id == bookingRule.Id);
             if (idx >= 0)
             {
@@ -38,26 +33,20 @@ namespace Schaad.Accounting.Repositories
                 bookingRule.Id = Guid.NewGuid().ToString();
                 bookingRules.Add(bookingRule);
             }
-            Save(bookingRules, BOOKING_RULES);
+            await SaveAsync(bookingRules, BOOKING_RULES);
         }
 
-        /// <summary>
+        public async Task<BookingRule> GetBookingRuleAsync(string id)
-        /// Get booking rule
-        /// </summary>
-        public BookingRule GetBookingRule(string id)
         {
-            var bookingRules = GetBookingRuleList();
+            var bookingRules = await GetBookingRuleListAsync();
             return bookingRules.FirstOrDefault(t => t.Id == id);
         }
 
-        /// <summary>
+        public async Task DeleteBookingRuleAsync(string id)
-        /// Delete booking rule
-        /// </summary>
-        public void DeleteBookingRule(string id)
         {
-            var bookingRules = GetBookingRuleList();
+            var bookingRules = await GetBookingRuleListAsync();
             bookingRules.RemoveAll(t => t.Id == id);
-            Save(bookingRules, BOOKING_RULES);
+            await SaveAsync(bookingRules, BOOKING_RULES);
         }
     }
 }

Schaad.Accounting.Db/Repositories/BookingTextRepository.cs

@@ -1,6 +1,7 @@
-using System;
+using System;
 using System.Collections.Generic;
 using System.Linq;
+using System.Threading.Tasks;
 using Microsoft.Extensions.Logging;
 using Schaad.Accounting.Interfaces;
 using Schaad.Accounting.Models;
@@ -17,17 +18,11 @@ namespace Schaad.Accounting.Repositories
             EnsureFileExists(BOOKING_TEXTS);
         }
 
-        /// <summary>
+        public Task<List<BookingText>> GetBookingTextListAsync() => LoadListAsync<BookingText>(BOOKING_TEXTS);
-        /// Load booking texts
-        /// </summary>
-        public List<BookingText> GetBookingTextList() => LoadList<BookingText>(BOOKING_TEXTS);
 
-        /// <summary>
+        public async Task SaveBookingTextAsync(BookingText bookingText)
-        /// Save a booking text (insert/update)
-        /// </summary>
-        public void SaveBookingText(BookingText bookingText)
         {
-            var bookingTexts = GetBookingTextList();
+            var bookingTexts = await GetBookingTextListAsync();
             var idx = bookingTexts.FindIndex(t => t.Id == bookingText.Id);
             if (idx >= 0)
             {
@@ -38,26 +33,20 @@ namespace Schaad.Accounting.Repositories
                 bookingText.Id = Guid.NewGuid().ToString();
                 bookingTexts.Add(bookingText);
             }
-            Save(bookingTexts, BOOKING_TEXTS);
+            await SaveAsync(bookingTexts, BOOKING_TEXTS);
         }
 
-        /// <summary>
+        public async Task<BookingText> GetBookingTextAsync(string id)
-        /// Get booking text
-        /// </summary>
-        public BookingText GetBookingText(string id)
         {
-            var bookingTexts = GetBookingTextList();
+            var bookingTexts = await GetBookingTextListAsync();
             return bookingTexts.FirstOrDefault(t => t.Id == id);
         }
 
-        /// <summary>
+        public async Task DeleteBookingTextAsync(string id)
-        /// Delete booking text
-        /// </summary>
-        public void DeleteBookingText(string id)
         {
-            var bookingTexts = GetBookingTextList();
+            var bookingTexts = await GetBookingTextListAsync();
             bookingTexts.RemoveAll(t => t.Id == id);
-            Save(bookingTexts, BOOKING_TEXTS);
+            await SaveAsync(bookingTexts, BOOKING_TEXTS);
         }
     }
 }

Schaad.Accounting.Db/Repositories/SplitPredefinitionRepository.cs

@@ -1,6 +1,7 @@
 using System;
 using System.Collections.Generic;
 using System.Linq;
+using System.Threading.Tasks;
 using Microsoft.Extensions.Logging;
 using Schaad.Accounting.Interfaces;
 using Schaad.Accounting.Models;
@@ -17,17 +18,11 @@ namespace Schaad.Accounting.Repositories
             EnsureFileExists(SPLIT_PREDEFINITION);
         }
 
-        /// <summary>
+        public Task<List<SplitPredefinition>> GetSplitPredefinitionListAsync() => LoadListAsync<SplitPredefinition>(SPLIT_PREDEFINITION);
-        /// Load split predefinitions
-        /// </summary>
-        public List<SplitPredefinition> GetSplitPredefinitionList() => LoadList<SplitPredefinition>(SPLIT_PREDEFINITION);
 
-        /// <summary>
+        public async Task SaveSplitPredefinitionAsync(SplitPredefinition splitPredefinition)
-        /// Save a split predefinition (insert/update)
-        /// </summary>
-        public void SaveSplitPredefinition(SplitPredefinition splitPredefinition)
         {
-            var definitions = GetSplitPredefinitionList();
+            var definitions = await GetSplitPredefinitionListAsync();
             var idx = definitions.FindIndex(d => d.Id == splitPredefinition.Id);
             if (idx >= 0)
             {
@@ -38,7 +33,7 @@ namespace Schaad.Accounting.Repositories
                 splitPredefinition.Id = Guid.NewGuid().ToString();
                 definitions.Add(splitPredefinition);
             }
-            Save(definitions, SPLIT_PREDEFINITION);
+            await SaveAsync(definitions, SPLIT_PREDEFINITION);
         }
     }
 }

Schaad.Accounting.Db/Repositories/SubclassRepository.cs

@@ -1,6 +1,7 @@
-using System;
+using System;
 using System.Collections.Generic;
 using System.Linq;
+using System.Threading.Tasks;
 using Microsoft.Extensions.Logging;
 using Schaad.Accounting.Interfaces;
 using Schaad.Accounting.Models;
@@ -23,17 +24,11 @@ namespace Schaad.Accounting.Repositories
             classes.Add(ClassIds.Expenses, "Ausgaben");
         }
 
-        /// <summary>
+        public Task<List<SubClass>> GetSubClassListAsync() => LoadListAsync<SubClass>(SUBCLASSES);
-        /// Load subclasses
-        /// </summary>
-        public List<SubClass> GetSubClassList() => LoadList<SubClass>(SUBCLASSES);
 
-        /// <summary>
+        public async Task SaveSubClassAsync(SubClass subClass)
-        /// Save a subclass (insert/update)
-        /// </summary>
-        public void SaveSubClass(SubClass subClass)
         {
-            var subclasses = GetSubClassList();
+            var subclasses = await GetSubClassListAsync();
             var idx = subclasses.FindIndex(s => s.Id == subClass.Id);
             if (idx >= 0)
             {
@@ -44,23 +39,20 @@ namespace Schaad.Accounting.Repositories
                 subClass.Id = Guid.NewGuid().ToString();
                 subclasses.Add(subClass);
             }
-            Save(subclasses, SUBCLASSES);
+            await SaveAsync(subclasses, SUBCLASSES);
         }
 
-        /// <summary>
+        public async Task<SubClass> GetSubClassAsync(string id)
-        /// Get subclass
-        /// </summary>
-        public SubClass GetSubClass(string id)
         {
-            var subclasses = GetSubClassList();
+            var subclasses = await GetSubClassListAsync();
             return subclasses.FirstOrDefault(t => t.Id == id);
         }
 
-        public void DeleteSubClass(string id)
+        public async Task DeleteSubClassAsync(string id)
         {
-            var subclasses = GetSubClassList();
+            var subclasses = await GetSubClassListAsync();
             subclasses.RemoveAll(t => t.Id == id);
-            Save(subclasses, SUBCLASSES);
+            await SaveAsync(subclasses, SUBCLASSES);
         }
 
         public Dictionary<int, string> GetClasses()

Schaad.Accounting.Db/Repositories/TransactionRepository.cs

@@ -1,6 +1,7 @@
-using System;
+using System;
 using System.Collections.Generic;
 using System.Linq;
+using System.Threading.Tasks;
 using Microsoft.Extensions.Logging;
 using Schaad.Accounting.Interfaces;
 using Schaad.Accounting.Models;
@@ -18,20 +19,14 @@ namespace Schaad.Accounting.Repositories
             this.accountRepository = accountRepository;
         }
 
-        /// <summary>
+        public Task<List<Transaction>> GetTransactionListAsync() => LoadListAsync<Transaction>(TRANSACTIONS);
-        /// Get transaction list
-        /// </summary>
-        public List<Transaction> GetTransactionList() => LoadList<Transaction>(TRANSACTIONS);
 
-        /// <summary>
+        public async Task SaveTransactionAsync(Transaction transaction)
-        /// Save a transaction (insert/update)
-        /// </summary>
-        public void SaveTransaction(Transaction transaction)
         {
             transaction.Value = Math.Abs(transaction.Value);
 
-            var originIsFx = accountRepository.GetAccount(transaction.OriginAccountId).IsFxAccount;
+            var originIsFx = (await accountRepository.GetAccountAsync(transaction.OriginAccountId)).IsFxAccount;
-            var targetIsFx = accountRepository.GetAccount(transaction.TargetAccountId).IsFxAccount;
+            var targetIsFx = (await accountRepository.GetAccountAsync(transaction.TargetAccountId)).IsFxAccount;
             var isFxAccount = originIsFx || targetIsFx;
 
             // user enters amount in the foreign account's currency -> convert to CHF for storage
@@ -50,7 +45,7 @@ namespace Schaad.Accounting.Repositories
                 transaction.BookingDate = transaction.ValueDate;
             }
 
-            var transactionList = GetTransactionList();
+            var transactionList = await GetTransactionListAsync();
             var idx = transactionList.FindIndex(t => t.Id == transaction.Id);
             if (idx >= 0)
             {
@@ -61,15 +56,12 @@ namespace Schaad.Accounting.Repositories
                 transaction.Id = Guid.NewGuid().ToString();
                 transactionList.Add(transaction);
             }
-            Save(transactionList, TRANSACTIONS);
+            await SaveAsync(transactionList, TRANSACTIONS);
         }
 
-        /// <summary>
+        public async Task<Transaction> GetTransactionAsync(string id)
-        /// Get transaction
-        /// </summary>
-        public Transaction GetTransaction(string id)
         {
-            var transactions = GetTransactionList();
+            var transactions = await GetTransactionListAsync();
             var stored = transactions.FirstOrDefault(t => t.Id == id);
             if (stored == null)
             {
@@ -79,8 +71,8 @@ namespace Schaad.Accounting.Repositories
             var result = stored.Clone();
 
             // value is stored in CHF -> convert back to foreign currency for display/editing
-            var isFxAccount = accountRepository.GetAccount(result.OriginAccountId).IsFxAccount
+            var isFxAccount = (await accountRepository.GetAccountAsync(result.OriginAccountId)).IsFxAccount
-                || accountRepository.GetAccount(result.TargetAccountId).IsFxAccount;
+                || (await accountRepository.GetAccountAsync(result.TargetAccountId)).IsFxAccount;
             if (isFxAccount && result.FxRate != 0)
             {
                 result.Value = result.Value / result.FxRate.Value;
@@ -89,14 +81,11 @@ namespace Schaad.Accounting.Repositories
             return result;
         }
 
-        /// <summary>
+        public async Task DeleteTransactionAsync(string id)
-        /// Delete transaction
-        /// </summary>
-        public void DeleteTransaction(string id)
         {
-            var transactions = GetTransactionList();
+            var transactions = await GetTransactionListAsync();
             transactions.RemoveAll(t => t.Id == id);
-            Save(transactions, TRANSACTIONS);
+            await SaveAsync(transactions, TRANSACTIONS);
         }
     }
 }

Schaad.Accounting.Db/RepositoryCache.cs

@@ -1,5 +1,6 @@
 using System;
 using System.Collections.Generic;
+using System.Threading.Tasks;
 
 namespace Schaad.Accounting.Repositories
 {
@@ -7,7 +8,7 @@ namespace Schaad.Accounting.Repositories
     /// Per-scope cache of deserialized XML lists, keyed by absolute file path.
     ///
     /// Registered as Scoped so it lives for the SignalR circuit; each XML file is
-    /// then loaded at most once per circuit. Writes go through <see cref="BaseRepository.Save"/>,
+    /// then loaded at most once per circuit. Writes go through <see cref="BaseRepository.SaveAsync"/>,
     /// which invalidates the corresponding entry so the next read reloads from disk.
     ///
     /// Not thread-safe — callers within a single Blazor Server circuit run serialized on the
@@ -18,14 +19,14 @@ namespace Schaad.Accounting.Repositories
         private readonly Dictionary<string, object> entries =
             new(StringComparer.OrdinalIgnoreCase);
 
-        public List<T> GetOrLoad<T>(string cacheKey, Func<List<T>> loader)
+        public async Task<List<T>> GetOrLoadAsync<T>(string cacheKey, Func<Task<List<T>>> loader)
         {
             if (entries.TryGetValue(cacheKey, out var cached))
             {
                 return (List<T>)cached;
             }
 
-            var list = loader();
+            var list = await loader();
             entries[cacheKey] = list;
             return list;
         }

Schaad.Accounting.Services/ChartService.cs

@@ -1,6 +1,7 @@
 using System;
 using System.Collections.Generic;
 using System.Linq;
+using System.Threading.Tasks;
 using Schaad.Accounting.Datasets;
 using Schaad.Accounting.Datasets.Charts;
 using Schaad.Accounting.Interfaces;
@@ -18,9 +19,9 @@ namespace Schaad.Accounting.Services
             this.viewService = viewService;
         }
 
-        public IReadOnlyList<DataSerie> GetExpensesPerMonth()
+        public async Task<IReadOnlyList<DataSerie>> GetExpensesPerMonthAsync()
         {
-            var expenseTransactions = viewService.GetTransactionViewList()
+            var expenseTransactions = (await viewService.GetTransactionViewListAsync())
                 .Where(t => t.TargetAccount.Class == ClassIds.Expenses)
                 .ToList();
 
@@ -31,7 +32,7 @@ namespace Schaad.Accounting.Services
 
             return distinctSubClasses > 1
                 ? GetSubClassExpensesPerMonth(expenseTransactions)
-                : GetAccountExpensesPerMonth();
+                : await GetAccountExpensesPerMonthAsync();
         }
 
         private List<DataSerie> GetSubClassExpensesPerMonth(List<TransactionDataset> expenseTransactions)
@@ -59,11 +60,11 @@ namespace Schaad.Accounting.Services
             return list;
         }
 
-        private List<DataSerie> GetAccountExpensesPerMonth()
+        private async Task<List<DataSerie>> GetAccountExpensesPerMonthAsync()
         {
             var year = settingsService.GetYear();
-            var allTransactions = viewService.GetTransactionViewList();
+            var allTransactions = await viewService.GetTransactionViewListAsync();
-            var expenseAccounts = viewService.GetAccountViewList().Where(a => a.Class == ClassIds.Expenses);
+            var expenseAccounts = (await viewService.GetAccountViewListAsync()).Where(a => a.Class == ClassIds.Expenses);
 
             var list = new List<DataSerie>();
             foreach (var account in expenseAccounts)

Schaad.Accounting.Services/FileService.cs

@@ -2,6 +2,7 @@ using System.Collections.Generic;
 using System.IO.Compression;
 using System.Linq;
 using System.Text;
+using System.Threading.Tasks;
 using Microsoft.Extensions.Logging;
 using Schaad.Accounting.Datasets;
 using Schaad.Accounting.Interfaces;
@@ -47,15 +48,14 @@ namespace Schaad.Accounting.Services
         }
 
         // Upload account statement file (mt940, camt053)
-        // http://www.mikesdotnetting.com/article/288/asp-net-5-uploading-files-with-asp-net-mvc-6
+        public async Task<IReadOnlyList<MessageDataset>> ImportAccountStatementFileAsync(string filePath)
-        public IReadOnlyList<MessageDataset> ImportAccountStatementFile(string filePath)
         {
             logger.LogInformation("Importing account statement file {FilePath}", filePath);
 
             var messages = new List<MessageDataset>();
             var accountStatementResults = accountStatementService.ReadFile(filePath, Encoding.UTF8);
 
-            var accountList = accountRepository.GetAccountList().Select(a => a.BankAccountNumber).ToList();
+            var accountList = (await accountRepository.GetAccountListAsync()).Select(a => a.BankAccountNumber).ToList();
             foreach (var accountStatementResult in accountStatementResults)
             {
                 var account = accountStatementResult.AccountStatement;
@@ -91,8 +91,8 @@ namespace Schaad.Accounting.Services
                                 Creditor = t.Creditor
                             })
                         .ToList();
-                    var count = bankTransactionRepository.SaveBankTransactionList(account.AccountNumber, transactionsThisYear);
+                    var count = await bankTransactionRepository.SaveBankTransactionListAsync(account.AccountNumber, transactionsThisYear);
-                    accountRepository.SaveBankAccountBalance(account.AccountNumber, (decimal)account.EndBalance.Value);
+                    await accountRepository.SaveBankAccountBalanceAsync(account.AccountNumber, (decimal)account.EndBalance.Value);
 
                     logger.LogInformation("Imported {Imported} of {Total} transactions for account {AccountNumber}",
                         count, account.Transactions.Count, account.AccountNumber);
@@ -124,11 +124,11 @@ namespace Schaad.Accounting.Services
             return creditCardTransactions;
         }
 
-        public byte[] GetTransactionListCsv(string accountId)
+        public async Task<byte[]> GetTransactionListCsvAsync(string accountId)
         {
             var sb = new StringBuilder();
-            var account = accountRepository.GetAccount(accountId);
+            var account = await accountRepository.GetAccountAsync(accountId);
-            var transactions = transactionsRepository.GetTransactionList()
+            var transactions = (await transactionsRepository.GetTransactionListAsync())
                 .Where(t => t.OriginAccountId == accountId || t.TargetAccountId == accountId)
                 .OrderBy(t => t.BookingDate)
                 .ThenBy(t => t.ValueDate)

Schaad.Accounting.Services/Interfaces/IChartService.cs

@@ -1,10 +1,11 @@
 using System.Collections.Generic;
+using System.Threading.Tasks;
 using Schaad.Accounting.Datasets.Charts;
 
 namespace Schaad.Accounting.Interfaces
 {
     public interface IChartService
     {
-        IReadOnlyList<DataSerie> GetExpensesPerMonth();
+        Task<IReadOnlyList<DataSerie>> GetExpensesPerMonthAsync();
     }
 }

Schaad.Accounting.Services/Interfaces/IFileService.cs

@@ -1,4 +1,5 @@
 using System.Collections.Generic;
+using System.Threading.Tasks;
 using Schaad.Accounting.Datasets;
 using Schaad.Finance.Api;
 using Schaad.Finance.Api.Datasets;
@@ -8,8 +9,8 @@ namespace Schaad.Accounting.Interfaces
     public interface IFileService
     {
         string Backup();
-        IReadOnlyList<MessageDataset> ImportAccountStatementFile(string filePath);
+        Task<IReadOnlyList<MessageDataset>> ImportAccountStatementFileAsync(string filePath);
         IReadOnlyList<CreditCardTransaction> ImportCreditCardStatementFile(CreditCardProvider creditCardProvider, string filePath);
-        byte[] GetTransactionListCsv(string accountId);
+        Task<byte[]> GetTransactionListCsvAsync(string accountId);
     }
 }

Schaad.Accounting.Services/Interfaces/IViewService.cs

@@ -1,4 +1,5 @@
 using System.Collections.Generic;
+using System.Threading.Tasks;
 using Schaad.Accounting.Datasets;
 using Schaad.Accounting.Datasets.Reports;
 using Schaad.Accounting.Models;
@@ -8,24 +9,24 @@ namespace Schaad.Accounting.Interfaces
 {
     public interface IViewService
     {
-        AccountDataset GetAccountView(string id);
+        Task<AccountDataset> GetAccountViewAsync(string id);
 
-        List<AccountDataset> GetAccountViewList();
+        Task<List<AccountDataset>> GetAccountViewListAsync();
 
-        BalanceDataset GetBalanceView();
+        Task<BalanceDataset> GetBalanceViewAsync();
 
-        BalanceSheetDataset GetBalanceSheetView(int year);
+        Task<BalanceSheetDataset> GetBalanceSheetViewAsync(int year);
 
-        List<TransactionDataset> GetTransactionViewList();
+        Task<List<TransactionDataset>> GetTransactionViewListAsync();
 
-        List<TransactionDataset> GetTransactionViewList(string accountId);
+        Task<List<TransactionDataset>> GetTransactionViewListAsync(string accountId);
 
-        List<BookingRuleDataset> GetBookingRuleViewList();
+        Task<List<BookingRuleDataset>> GetBookingRuleViewListAsync();
 
-        List<BankTransaction> GetOpenBankTransactionList();
+        Task<List<BankTransaction>> GetOpenBankTransactionListAsync();
 
-        List<Transaction> MatchOpenBankTransactions();
+        Task<List<Transaction>> MatchOpenBankTransactionsAsync();
 
-        List<Transaction> MatchCreditCardTransactions(string bankTransactionId, IReadOnlyList<CreditCardTransaction> creditCardTransactions);
+        Task<List<Transaction>> MatchCreditCardTransactionsAsync(string bankTransactionId, IReadOnlyList<CreditCardTransaction> creditCardTransactions);
     }
 }

Schaad.Accounting.Services/ViewService.cs

@@ -1,6 +1,7 @@
 using System;
 using System.Collections.Generic;
 using System.Linq;
+using System.Threading.Tasks;
 using Microsoft.Extensions.Logging;
 using Schaad.Accounting.Datasets;
 using Schaad.Accounting.Datasets.Reports;
@@ -38,23 +39,17 @@ namespace Schaad.Accounting.Services
             this.logger = logger;
         }
 
-        /// <summary>
+        public async Task<AccountDataset> GetAccountViewAsync(string id)
-        /// Load accounts
-        /// </summary>
-        public AccountDataset GetAccountView(string id)
         {
-            var accounts = GetAccountViewList();
+            var accounts = await GetAccountViewListAsync();
             return accounts.Single(t => t.Id == id);
         }
 
-        /// <summary>
+        public async Task<List<AccountDataset>> GetAccountViewListAsync()
-        /// Load accounts and calculates their balances
-        /// </summary>
-        public List<AccountDataset> GetAccountViewList()
         {
-            var accounts = accountRepository.GetAccountList();
+            var accounts = await accountRepository.GetAccountListAsync();
-            var transactionList = GetTransactionViewList();
+            var transactionList = await GetTransactionViewListAsync();
-            var subClassNameByNumber = subclassRepository.GetSubClassList().ToDictionary(s => s.Number, s => s.Name);
+            var subClassNameByNumber = (await subclassRepository.GetSubClassListAsync()).ToDictionary(s => s.Number, s => s.Name);
 
             // Group transactions by account so per-account balance is O(k) instead of O(M).
             var creditsByAccount = transactionList.GroupBy(t => t.TargetAccountId).ToDictionary(g => g.Key, g => g.ToList());
@@ -93,9 +88,9 @@ namespace Schaad.Accounting.Services
             return balance;
         }
 
-        public BalanceDataset GetBalanceView()
+        public async Task<BalanceDataset> GetBalanceViewAsync()
         {
-            var accountList = GetAccountViewList();
+            var accountList = await GetAccountViewListAsync();
             return new BalanceDataset(
                 ActivaAccountList: accountList.Where(m => m.Class == ClassIds.Activa).ToList(),
                 PassivaAccountList: accountList.Where(m => m.Class == ClassIds.Passiva).ToList(),
@@ -103,32 +98,30 @@ namespace Schaad.Accounting.Services
                 TotalPassivaCHF: Math.Abs(accountList.Where(m => m.Class == ClassIds.Passiva).Sum(m => m.BalanceCHF)));
         }
 
-        public BalanceSheetDataset GetBalanceSheetView(int year)
+        public async Task<BalanceSheetDataset> GetBalanceSheetViewAsync(int year)
         {
-            var accountList = GetAccountViewList();
+            var accountList = await GetAccountViewListAsync();
 
             var profit = Math.Abs(accountList.Where(m => m.Class == ClassIds.Income).Sum(m => m.BalanceCHF));
             profit += Math.Abs(accountList.Where(m => m.Class == ClassIds.Activa).Sum(m => fxConverter.ConvertToChf(m.StartBalance, m.Currency)));
             var loss = Math.Abs(accountList.Where(m => m.Class == ClassIds.Expenses).Sum(m => m.BalanceCHF));
 
-            var balanceView = new BalanceSheetDataset(
+            return new BalanceSheetDataset(
                 ActivaAccountList: accountList.Where(m => m.Class == ClassIds.Activa).ToList(),
                 IncomeAccountList: accountList.Where(m => m.Class == ClassIds.Income).ToList(),
                 ExpensesAccountList: accountList.Where(m => m.Class == ClassIds.Expenses).ToList(),
                 ProfitCHF: profit,
                 LossCHF: loss,
                 Year: year);
-
-            return balanceView;
         }
 
         /// <summary>
         /// Get transaction list with the origin and target account for each transaction
         /// </summary>
-        public List<TransactionDataset> GetTransactionViewList()
+        public async Task<List<TransactionDataset>> GetTransactionViewListAsync()
         {
-            var accountsById = accountRepository.GetAccountList().ToDictionary(a => a.Id);
+            var accountsById = (await accountRepository.GetAccountListAsync()).ToDictionary(a => a.Id);
-            var transactionList = transactionRepository.GetTransactionList();
+            var transactionList = await transactionRepository.GetTransactionListAsync();
 
             return transactionList.Select(t =>
                     new TransactionDataset(
@@ -139,12 +132,13 @@ namespace Schaad.Accounting.Services
         }
 
         /// <summary>
-        /// Get transaction list with the origin and target account for each transaction
+        /// Get transaction list filtered to a single account, with values sign-flipped
+        /// when the requested account is the origin of an activa booking.
         /// </summary>
-        public List<TransactionDataset> GetTransactionViewList(string accountId)
+        public async Task<List<TransactionDataset>> GetTransactionViewListAsync(string accountId)
         {
-            var accountsById = accountRepository.GetAccountList().ToDictionary(a => a.Id);
+            var accountsById = (await accountRepository.GetAccountListAsync()).ToDictionary(a => a.Id);
-            var transactionList = transactionRepository.GetTransactionList()
+            var transactionList = (await transactionRepository.GetTransactionListAsync())
                 .Where(t => t.OriginAccountId == accountId || t.TargetAccountId == accountId);
 
             return transactionList.Select(t =>
@@ -170,10 +164,10 @@ namespace Schaad.Accounting.Services
         /// <summary>
         /// Get booking rules with their account
         /// </summary>
-        public List<BookingRuleDataset> GetBookingRuleViewList()
+        public async Task<List<BookingRuleDataset>> GetBookingRuleViewListAsync()
         {
-            var accountsById = accountRepository.GetAccountList().ToDictionary(a => a.Id);
+            var accountsById = (await accountRepository.GetAccountListAsync()).ToDictionary(a => a.Id);
-            var bookingRules = bookingRuleRepository.GetBookingRuleList();
+            var bookingRules = await bookingRuleRepository.GetBookingRuleListAsync();
 
             return bookingRules.Select(t =>
                     new BookingRuleDataset(t, accountsById[t.AccountId].Name))
@@ -183,28 +177,26 @@ namespace Schaad.Accounting.Services
         /// <summary>
         /// Load open bank transactions
         /// </summary>
-        public List<BankTransaction> GetOpenBankTransactionList()
+        public async Task<List<BankTransaction>> GetOpenBankTransactionListAsync()
         {
-            var transactions = transactionRepository
+            var transactions = (await transactionRepository.GetTransactionListAsync())
-                .GetTransactionList()
                 .Where(t => string.IsNullOrEmpty(t.BankTransactionId) == false)
                 .Select(t => t.BankTransactionId);
 
-            var bankTransactions = bankTransactionRepository
+            var bankTransactions = (await bankTransactionRepository.GetBankTransactionListAsync())
-                .GetBankTransactionList()
                 .Where(b => b.Ignore == false && transactions.Contains(b.Id) == false)
                 .ToList();
 
             return bankTransactions;
         }
 
-        public List<Transaction> MatchOpenBankTransactions()
+        public async Task<List<Transaction>> MatchOpenBankTransactionsAsync()
         {
             var newTransactionList = new List<Transaction>();
-            var transactions = transactionRepository.GetTransactionList();
+            var transactions = await transactionRepository.GetTransactionListAsync();
-            var accounts = accountRepository.GetAccountList();
+            var accounts = await accountRepository.GetAccountListAsync();
-            var bookingRules = bookingRuleRepository.GetBookingRuleList();
+            var bookingRules = await bookingRuleRepository.GetBookingRuleListAsync();
-            var bankTransactions = GetOpenBankTransactionList().OrderBy(t => t.ValueDate).ToList();
+            var bankTransactions = (await GetOpenBankTransactionListAsync()).OrderBy(t => t.ValueDate).ToList();
             foreach (var bankTransaction in bankTransactions)
             {
                 var trx = new Transaction(bankTransaction, accounts);
@@ -216,14 +208,15 @@ namespace Schaad.Accounting.Services
 
             var matched = newTransactionList.Count(t => string.IsNullOrEmpty(t.Text) == false);
             logger.LogInformation("Matched {Matched} of {Total} open bank transactions", matched, bankTransactions.Count);
+
             return newTransactionList;
         }
 
-        public List<Transaction> MatchCreditCardTransactions(string bankTransactionId, IReadOnlyList<CreditCardTransaction> creditCardTransactions)
+        public async Task<List<Transaction>> MatchCreditCardTransactionsAsync(string bankTransactionId, IReadOnlyList<CreditCardTransaction> creditCardTransactions)
         {
-            var accounts = accountRepository.GetAccountList();
+            var accounts = await accountRepository.GetAccountListAsync();
-            var bankTrx = bankTransactionRepository.GetBankTransaction(bankTransactionId);
+            var bankTrx = await bankTransactionRepository.GetBankTransactionAsync(bankTransactionId);
-            var bookingRules = bookingRuleRepository.GetBookingRuleList();
+            var bookingRules = await bookingRuleRepository.GetBookingRuleListAsync();
 
             var trxList = new List<Transaction>();
             foreach (var creditCardTransaction in creditCardTransactions)

Schaad.Accounting.Tests/AccountRepositoryTestShould.cs

@@ -34,79 +34,79 @@ public class AccountRepositoryTestShould : IDisposable
     }
 
     [Fact]
-    public void AssignNewIdWhenSavingAccountWithoutId()
+    public async Task AssignNewIdWhenSavingAccountWithoutId()
     {
         var account = new Account { Number = 1000, Name = "Cash", Currency = "CHF" };
 
-        sut.SaveAccount(account);
+        await sut.SaveAccountAsync(account);
 
-        var stored = sut.GetAccountList().Single();
+        var stored = (await sut.GetAccountListAsync()).Single();
         stored.Id.ShouldNotBeNullOrEmpty();
         stored.Name.ShouldBe("Cash");
     }
 
     [Fact]
-    public void UpdateInPlaceWhenSavingAccountWithExistingId()
+    public async Task UpdateInPlaceWhenSavingAccountWithExistingId()
     {
-        sut.SaveAccount(new Account { Number = 1000, Name = "Cash", Currency = "CHF" });
+        await sut.SaveAccountAsync(new Account { Number = 1000, Name = "Cash", Currency = "CHF" });
-        var id = sut.GetAccountList().Single().Id;
+        var id = (await sut.GetAccountListAsync()).Single().Id;
 
-        sut.SaveAccount(new Account { Id = id, Number = 1000, Name = "Cash renamed", Currency = "CHF" });
+        await sut.SaveAccountAsync(new Account { Id = id, Number = 1000, Name = "Cash renamed", Currency = "CHF" });
 
-        var accounts = sut.GetAccountList();
+        var accounts = await sut.GetAccountListAsync();
         accounts.Count.ShouldBe(1);
         accounts[0].Name.ShouldBe("Cash renamed");
     }
 
     [Fact]
-    public void DefaultCurrencyToChfWhenSavingAccountWithoutCurrency()
+    public async Task DefaultCurrencyToChfWhenSavingAccountWithoutCurrency()
     {
-        sut.SaveAccount(new Account { Number = 1000, Name = "Cash", Currency = null! });
+        await sut.SaveAccountAsync(new Account { Number = 1000, Name = "Cash", Currency = null! });
 
-        sut.GetAccountList().Single().Currency.ShouldBe("CHF");
+        (await sut.GetAccountListAsync()).Single().Currency.ShouldBe("CHF");
     }
 
     [Fact]
-    public void RemoveAccountWhenDeletingById()
+    public async Task RemoveAccountWhenDeletingById()
     {
-        sut.SaveAccount(new Account { Number = 1000, Name = "Cash", Currency = "CHF" });
+        await sut.SaveAccountAsync(new Account { Number = 1000, Name = "Cash", Currency = "CHF" });
-        var id = sut.GetAccountList().Single().Id;
+        var id = (await sut.GetAccountListAsync()).Single().Id;
 
-        sut.DeleteAccount(id);
+        await sut.DeleteAccountAsync(id);
 
-        sut.GetAccountList().ShouldBeEmpty();
+        (await sut.GetAccountListAsync()).ShouldBeEmpty();
     }
 
     [Fact]
-    public void ReturnAccountWhenLookingUpByBankAccountNumber()
+    public async Task ReturnAccountWhenLookingUpByBankAccountNumber()
     {
-        sut.SaveAccount(new Account { Number = 1010, Name = "Checking", Currency = "CHF", BankAccountNumber = "CH01" });
+        await sut.SaveAccountAsync(new Account { Number = 1010, Name = "Checking", Currency = "CHF", BankAccountNumber = "CH01" });
-        sut.SaveAccount(new Account { Number = 1020, Name = "Savings", Currency = "CHF", BankAccountNumber = "CH02" });
+        await sut.SaveAccountAsync(new Account { Number = 1020, Name = "Savings", Currency = "CHF", BankAccountNumber = "CH02" });
 
-        sut.GetAccountForBankAccountNumber("CH01").Name.ShouldBe("Checking");
+        (await sut.GetAccountForBankAccountNumberAsync("CH01")).Name.ShouldBe("Checking");
-        sut.GetAccountForBankAccountNumber("CH02").Name.ShouldBe("Savings");
+        (await sut.GetAccountForBankAccountNumberAsync("CH02")).Name.ShouldBe("Savings");
-        sut.GetAccountForBankAccountNumber("CH99").ShouldBeNull();
+        (await sut.GetAccountForBankAccountNumberAsync("CH99")).ShouldBeNull();
     }
 
     [Fact]
-    public void UpdateLastBankBalanceWhenSavingBankBalance()
+    public async Task UpdateLastBankBalanceWhenSavingBankBalance()
     {
-        sut.SaveAccount(new Account { Number = 1010, Name = "Checking", Currency = "CHF", BankAccountNumber = "CH01" });
+        await sut.SaveAccountAsync(new Account { Number = 1010, Name = "Checking", Currency = "CHF", BankAccountNumber = "CH01" });
 
-        sut.SaveBankAccountBalance("CH01", 1234.56m);
+        await sut.SaveBankAccountBalanceAsync("CH01", 1234.56m);
 
-        sut.GetAccountForBankAccountNumber("CH01").LastBankBalance.ShouldBe(1234.56m);
+        (await sut.GetAccountForBankAccountNumberAsync("CH01")).LastBankBalance.ShouldBe(1234.56m);
     }
 
     [Fact]
-    public void SurviveConstructorReRunWhenAccountsFileAlreadyExists()
+    public async Task SurviveConstructorReRunWhenAccountsFileAlreadyExists()
     {
-        sut.SaveAccount(new Account { Number = 1000, Name = "Cash", Currency = "CHF" });
+        await sut.SaveAccountAsync(new Account { Number = 1000, Name = "Cash", Currency = "CHF" });
 
         // Re-construct with the same directory: existing file, no year rollover, no data loss.
         var fresh = new AccountRepository(settingsService, new RepositoryCache(), NullLogger<AccountRepository>.Instance);
 
-        var accounts = fresh.GetAccountList();
+        var accounts = await fresh.GetAccountListAsync();
         accounts.Count.ShouldBe(1);
         accounts[0].Name.ShouldBe("Cash");
     }

Schaad.Accounting.Tests/ChartServiceTestShould.cs

@@ -20,18 +20,18 @@ public class ChartServiceTestShould
     private ChartService BuildService() => new(settingsService, viewService);
 
     [Fact]
-    public void HonourSelectedYearWhenBuildingMonthlySeries()
+    public async Task HonourSelectedYearWhenBuildingMonthlySeries()
     {
         settingsService.GetYear().Returns(2023);
         var groceries = MakeAccount("groc", 4200);
         var checking = MakeAccount("chk", 1010);
-        viewService.GetAccountViewList().Returns(new List<AccountDataset> { AsDataset(groceries), AsDataset(checking) });
+        viewService.GetAccountViewListAsync().Returns(new List<AccountDataset> { AsDataset(groceries), AsDataset(checking) });
-        viewService.GetTransactionViewList().Returns(new List<TransactionDataset>
+        viewService.GetTransactionViewListAsync().Returns(new List<TransactionDataset>
         {
             MakeTransaction(checking, groceries, value: 50m, valueDate: new DateTime(2023, 4, 5))
         });
 
-        var series = BuildService().GetExpensesPerMonth();
+        var series = await BuildService().GetExpensesPerMonthAsync();
 
         series.Count.ShouldBe(1);
         series[0].X.ShouldAllBe(x => ((DateOnly)x).Year == 2023);
@@ -40,22 +40,22 @@ public class ChartServiceTestShould
     }
 
     [Fact]
-    public void GroupExpensesByAccountWhenAllExpensesShareOneSubClass()
+    public async Task GroupExpensesByAccountWhenAllExpensesShareOneSubClass()
     {
-        var mannenbach = MakeAccount("m1", 4000);       // SubClass 40
+        var mannenbach = MakeAccount("m1", 4000);
-        var mannenbach2 = MakeAccount("m2", 4001);      // SubClass 40 (same)
+        var mannenbach2 = MakeAccount("m2", 4001);
         var checking = MakeAccount("chk", 1010);
-        viewService.GetAccountViewList().Returns(new List<AccountDataset>
+        viewService.GetAccountViewListAsync().Returns(new List<AccountDataset>
         {
             AsDataset(mannenbach), AsDataset(mannenbach2), AsDataset(checking)
         });
-        viewService.GetTransactionViewList().Returns(new List<TransactionDataset>
+        viewService.GetTransactionViewListAsync().Returns(new List<TransactionDataset>
         {
             MakeTransaction(checking, mannenbach, value: 10m, valueDate: new DateTime(2026, 1, 1)),
             MakeTransaction(checking, mannenbach2, value: 20m, valueDate: new DateTime(2026, 1, 1))
         });
 
-        var series = BuildService().GetExpensesPerMonth();
+        var series = await BuildService().GetExpensesPerMonthAsync();
 
         series.Count.ShouldBe(2);
         series.ShouldContain(s => s.Id == "m1");
@@ -63,44 +63,44 @@ public class ChartServiceTestShould
     }
 
     [Fact]
-    public void GroupExpensesBySubClassWhenMultipleSubClassesAreUsed()
+    public async Task GroupExpensesBySubClassWhenMultipleSubClassesAreUsed()
     {
-        var groceries = MakeAccount("groc", 4200);      // SubClass 42
+        var groceries = MakeAccount("groc", 4200);
-        var utilities = MakeAccount("util", 4300);      // SubClass 43
+        var utilities = MakeAccount("util", 4300);
         var checking = MakeAccount("chk", 1010);
-        viewService.GetAccountViewList().Returns(new List<AccountDataset>
+        viewService.GetAccountViewListAsync().Returns(new List<AccountDataset>
         {
             AsDataset(groceries), AsDataset(utilities), AsDataset(checking)
         });
-        viewService.GetTransactionViewList().Returns(new List<TransactionDataset>
+        viewService.GetTransactionViewListAsync().Returns(new List<TransactionDataset>
         {
             MakeTransaction(checking, groceries, value: 50m, valueDate: new DateTime(2026, 1, 1)),
             MakeTransaction(checking, utilities, value: 30m, valueDate: new DateTime(2026, 2, 1))
         });
 
-        var series = BuildService().GetExpensesPerMonth();
+        var series = await BuildService().GetExpensesPerMonthAsync();
 
         series.Count.ShouldBe(2);
-        series.ShouldContain(s => s.Id == "42"); // sub-class number as id
+        series.ShouldContain(s => s.Id == "42");
         series.ShouldContain(s => s.Id == "43");
     }
 
     [Fact]
-    public void SkipAccountsWithoutTransactionsWhenBuildingSeries()
+    public async Task SkipAccountsWithoutTransactionsWhenBuildingSeries()
     {
-        var groceries = MakeAccount("groc", 4000);      // has activity
+        var groceries = MakeAccount("groc", 4000);
-        var utilities = MakeAccount("util", 4001);      // same subclass, no activity
+        var utilities = MakeAccount("util", 4001);
         var checking = MakeAccount("chk", 1010);
-        viewService.GetAccountViewList().Returns(new List<AccountDataset>
+        viewService.GetAccountViewListAsync().Returns(new List<AccountDataset>
         {
             AsDataset(groceries), AsDataset(utilities), AsDataset(checking)
         });
-        viewService.GetTransactionViewList().Returns(new List<TransactionDataset>
+        viewService.GetTransactionViewListAsync().Returns(new List<TransactionDataset>
         {
             MakeTransaction(checking, groceries, value: 50m, valueDate: new DateTime(2026, 1, 1))
         });
 
-        var series = BuildService().GetExpensesPerMonth();
+        var series = await BuildService().GetExpensesPerMonthAsync();
 
         series.Count.ShouldBe(1);
         series[0].Id.ShouldBe("groc");

Schaad.Accounting.Tests/FileServiceTestShould.cs

@@ -20,8 +20,6 @@ public class FileServiceTestShould
 
     public FileServiceTestShould()
     {
-        // Registering the ISO-8859-1 code page provider so the CSV encoding call works
-        // in the test host (which does not include legacy encodings by default).
         Encoding.RegisterProvider(CodePagesEncodingProvider.Instance);
     }
 
@@ -30,13 +28,11 @@ public class FileServiceTestShould
         accountStatementService, creditCardStatementService, NullLogger<FileService>.Instance);
 
     [Fact]
-    public void EmitHeaderRowAndRunningBalanceWhenExportingTransactionsCsv()
+    public async Task EmitHeaderRowAndRunningBalanceWhenExportingTransactionsCsv()
     {
         var checking = new Account { Id = "chk", Number = 1010, Name = "Checking", Currency = "CHF", StartBalance = 1000m };
-        var groceries = new Account { Id = "groc", Number = 4200, Name = "Groceries", Currency = "CHF" };
+        accountRepo.GetAccountAsync("chk").Returns(checking);
-        var salary = new Account { Id = "sal", Number = 3000, Name = "Salary", Currency = "CHF" };
+        transactionRepo.GetTransactionListAsync().Returns(new List<Transaction>
-        accountRepo.GetAccount("chk").Returns(checking);
-        transactionRepo.GetTransactionList().Returns(new List<Transaction>
         {
             new()
             {
@@ -50,26 +46,23 @@ public class FileServiceTestShould
             }
         });
 
-        var bytes = BuildService().GetTransactionListCsv("chk");
+        var bytes = await BuildService().GetTransactionListCsvAsync("chk");
         var csv = Encoding.GetEncoding("ISO-8859-1").GetString(bytes);
         var lines = csv.Split(Environment.NewLine, StringSplitOptions.RemoveEmptyEntries);
 
         lines[0].ShouldBe("Buchungsdatum;Valuta;Buchungstext;Belastung;Gutschrift;Saldo CHF");
         lines[1].ShouldBe(";;Startsaldo;;;1000");
-        // Debit line (outgoing) — value in Belastung column, balance drops
         lines[2].ShouldBe("05.01.2026;05.01.2026;Coop;50.00;;950.00");
-        // Credit line (incoming) — value in Gutschrift column, balance rises
         lines[3].ShouldBe("25.01.2026;25.01.2026;Salary;;5'000.00;5'950.00");
     }
 
     [Fact]
-    public void OrderTransactionsByBookingDateThenValueDateThenValueWhenExporting()
+    public async Task OrderTransactionsByBookingDateThenValueDateThenValueWhenExporting()
     {
         var checking = new Account { Id = "chk", Number = 1010, Name = "Checking", Currency = "CHF", StartBalance = 0m };
-        accountRepo.GetAccount("chk").Returns(checking);
+        accountRepo.GetAccountAsync("chk").Returns(checking);
-        transactionRepo.GetTransactionList().Returns(new List<Transaction>
+        transactionRepo.GetTransactionListAsync().Returns(new List<Transaction>
         {
-            // Deliberately unordered
             new() { OriginAccountId = "chk", TargetAccountId = "x", Value = 10m, Text = "later",
                     BookingDate = new DateTime(2026, 2, 1), ValueDate = new DateTime(2026, 2, 1) },
             new() { OriginAccountId = "chk", TargetAccountId = "x", Value = 5m, Text = "earlier small",
@@ -78,30 +71,28 @@ public class FileServiceTestShould
                     BookingDate = new DateTime(2026, 1, 15), ValueDate = new DateTime(2026, 1, 15) }
         });
 
-        var csv = Encoding.GetEncoding("ISO-8859-1").GetString(BuildService().GetTransactionListCsv("chk"));
+        var csv = Encoding.GetEncoding("ISO-8859-1").GetString(await BuildService().GetTransactionListCsvAsync("chk"));
         var lines = csv.Split(Environment.NewLine, StringSplitOptions.RemoveEmptyEntries);
 
-        // Skip header + start balance rows
         lines[2].ShouldContain("earlier small");
         lines[3].ShouldContain("earlier large");
         lines[4].ShouldContain("later");
     }
 
     [Fact]
-    public void NotMutateTransactionValueWhenExportingCsv()
+    public async Task NotMutateTransactionValueWhenExportingCsv()
     {
         var checking = new Account { Id = "chk", Number = 1010, Name = "Checking", Currency = "CHF" };
-        accountRepo.GetAccount("chk").Returns(checking);
+        accountRepo.GetAccountAsync("chk").Returns(checking);
         var outgoing = new Transaction
         {
             OriginAccountId = "chk", TargetAccountId = "x", Value = 42m, Text = "test",
             BookingDate = new DateTime(2026, 1, 1), ValueDate = new DateTime(2026, 1, 1)
         };
-        transactionRepo.GetTransactionList().Returns(new List<Transaction> { outgoing });
+        transactionRepo.GetTransactionListAsync().Returns(new List<Transaction> { outgoing });
 
-        BuildService().GetTransactionListCsv("chk");
+        await BuildService().GetTransactionListCsvAsync("chk");
 
-        // Regression: earlier code did `trx.Value *= -1` mid-loop.
         outgoing.Value.ShouldBe(42m);
     }
 }

Schaad.Accounting.Tests/RepositoryCacheTestShould.cs

@@ -6,13 +6,13 @@ namespace Schaad.Accounting.Tests;
 public class RepositoryCacheTestShould
 {
     [Fact]
-    public void CallLoaderOnceWhenKeyIsRequestedRepeatedly()
+    public async Task CallLoaderOnceWhenKeyIsRequestedRepeatedly()
     {
         var cache = new RepositoryCache();
         var loaderCalls = 0;
 
-        var first = cache.GetOrLoad("key", () => { loaderCalls++; return new List<int> { 1, 2 }; });
+        var first = await cache.GetOrLoadAsync("key", () => { loaderCalls++; return Task.FromResult(new List<int> { 1, 2 }); });
-        var second = cache.GetOrLoad("key", () => { loaderCalls++; return new List<int> { 99 }; });
+        var second = await cache.GetOrLoadAsync("key", () => { loaderCalls++; return Task.FromResult(new List<int> { 99 }); });
 
         loaderCalls.ShouldBe(1);
         second.ShouldBeSameAs(first);
@@ -20,12 +20,12 @@ public class RepositoryCacheTestShould
     }
 
     [Fact]
-    public void KeepEntriesSeparateWhenKeysDiffer()
+    public async Task KeepEntriesSeparateWhenKeysDiffer()
     {
         var cache = new RepositoryCache();
 
-        var a = cache.GetOrLoad("a", () => new List<int> { 1 });
+        var a = await cache.GetOrLoadAsync("a", () => Task.FromResult(new List<int> { 1 }));
-        var b = cache.GetOrLoad("b", () => new List<int> { 2 });
+        var b = await cache.GetOrLoadAsync("b", () => Task.FromResult(new List<int> { 2 }));
 
         b.ShouldNotBeSameAs(a);
         a.ShouldBe(new[] { 1 });
@@ -33,25 +33,25 @@ public class RepositoryCacheTestShould
     }
 
     [Fact]
-    public void ReloadFromLoaderWhenKeyIsInvalidated()
+    public async Task ReloadFromLoaderWhenKeyIsInvalidated()
     {
         var cache = new RepositoryCache();
         var loaderCalls = 0;
 
-        cache.GetOrLoad("k", () => { loaderCalls++; return new List<int> { 1 }; });
+        await cache.GetOrLoadAsync("k", () => { loaderCalls++; return Task.FromResult(new List<int> { 1 }); });
         cache.Invalidate("k");
-        cache.GetOrLoad("k", () => { loaderCalls++; return new List<int> { 2 }; });
+        await cache.GetOrLoadAsync("k", () => { loaderCalls++; return Task.FromResult(new List<int> { 2 }); });
 
         loaderCalls.ShouldBe(2);
     }
 
     [Fact]
-    public void MatchKeysCaseInsensitivelyWhenLookingUp()
+    public async Task MatchKeysCaseInsensitivelyWhenLookingUp()
     {
         var cache = new RepositoryCache();
 
-        cache.GetOrLoad("Path/To/File.xml", () => new List<int> { 1 });
+        await cache.GetOrLoadAsync("Path/To/File.xml", () => Task.FromResult(new List<int> { 1 }));
-        var upper = cache.GetOrLoad("PATH/TO/FILE.XML", () => new List<int> { 99 });
+        var upper = await cache.GetOrLoadAsync("PATH/TO/FILE.XML", () => Task.FromResult(new List<int> { 99 }));
 
         upper.ShouldBe(new[] { 1 });
     }

Schaad.Accounting.Tests/TransactionRepositoryTestShould.cs

@@ -38,12 +38,12 @@ public class TransactionRepositoryTestShould : IDisposable
     }
 
     [Fact]
-    public void PreserveValueWhenRoundTrippingNonFxTransaction()
+    public async Task PreserveValueWhenRoundTrippingNonFxTransaction()
     {
-        accountRepo.GetAccount("chk").Returns(new Account { Id = "chk", Currency = "CHF" });
+        accountRepo.GetAccountAsync("chk").Returns(new Account { Id = "chk", Currency = "CHF" });
-        accountRepo.GetAccount("groc").Returns(new Account { Id = "groc", Currency = "CHF" });
+        accountRepo.GetAccountAsync("groc").Returns(new Account { Id = "groc", Currency = "CHF" });
 
-        sut.SaveTransaction(new Transaction
+        await sut.SaveTransactionAsync(new Transaction
         {
             OriginAccountId = "chk",
             TargetAccountId = "groc",
@@ -53,22 +53,21 @@ public class TransactionRepositoryTestShould : IDisposable
             BookingDate = new DateTime(2026, 5, 10)
         });
 
-        var stored = sut.GetTransactionList().Single();
+        var stored = (await sut.GetTransactionListAsync()).Single();
-        var loaded = sut.GetTransaction(stored.Id);
+        var loaded = await sut.GetTransactionAsync(stored.Id);
 
         loaded.ShouldNotBeNull();
         loaded.Value.ShouldBe(42m);
-        loaded.FxRate.ShouldBeNull(); // Non-FX transactions have FxRate cleared
+        loaded.FxRate.ShouldBeNull();
     }
 
     [Fact]
-    public void StoreInChfAndReturnInAccountCurrencyWhenTransactionIsFx()
+    public async Task StoreInChfAndReturnInAccountCurrencyWhenTransactionIsFx()
     {
-        // User enters 100 USD at rate 0.9 CHF/USD -> stored as 90 CHF; read back as 100 USD.
+        accountRepo.GetAccountAsync("chk").Returns(new Account { Id = "chk", Currency = "CHF" });
-        accountRepo.GetAccount("chk").Returns(new Account { Id = "chk", Currency = "CHF" });
+        accountRepo.GetAccountAsync("usd").Returns(new Account { Id = "usd", Currency = "USD" });
-        accountRepo.GetAccount("usd").Returns(new Account { Id = "usd", Currency = "USD" });
 
-        sut.SaveTransaction(new Transaction
+        await sut.SaveTransactionAsync(new Transaction
         {
             OriginAccountId = "chk",
             TargetAccountId = "usd",
@@ -79,28 +78,28 @@ public class TransactionRepositoryTestShould : IDisposable
             BookingDate = new DateTime(2026, 5, 10)
         });
 
-        var stored = sut.GetTransactionList().Single();
+        var stored = (await sut.GetTransactionListAsync()).Single();
-        stored.Value.ShouldBe(90m); // stored in CHF
+        stored.Value.ShouldBe(90m);
 
-        var loaded = sut.GetTransaction(stored.Id);
+        var loaded = await sut.GetTransactionAsync(stored.Id);
         loaded.ShouldNotBeNull();
-        loaded.Value.ShouldBe(100m); // display currency
+        loaded.Value.ShouldBe(100m);
         loaded.FxRate.ShouldBe(0.9m);
     }
 
     [Fact]
-    public void ReturnNullWhenGettingUnknownTransactionId()
+    public async Task ReturnNullWhenGettingUnknownTransactionId()
     {
-        sut.GetTransaction("no-such-id").ShouldBeNull();
+        (await sut.GetTransactionAsync("no-such-id")).ShouldBeNull();
     }
 
     [Fact]
-    public void NotMutateStoredValueWhenGettingFxTransactionTwice()
+    public async Task NotMutateStoredValueWhenGettingFxTransactionTwice()
     {
-        accountRepo.GetAccount("chk").Returns(new Account { Id = "chk", Currency = "CHF" });
+        accountRepo.GetAccountAsync("chk").Returns(new Account { Id = "chk", Currency = "CHF" });
-        accountRepo.GetAccount("usd").Returns(new Account { Id = "usd", Currency = "USD" });
+        accountRepo.GetAccountAsync("usd").Returns(new Account { Id = "usd", Currency = "USD" });
 
-        sut.SaveTransaction(new Transaction
+        await sut.SaveTransactionAsync(new Transaction
         {
             OriginAccountId = "chk",
             TargetAccountId = "usd",
@@ -111,12 +110,11 @@ public class TransactionRepositoryTestShould : IDisposable
             BookingDate = new DateTime(2026, 5, 10)
         });
 
-        var stored = sut.GetTransactionList().Single();
+        var stored = (await sut.GetTransactionListAsync()).Single();
         var id = stored.Id;
 
-        // Get twice; if Get mutated the stored entity, the second call would divide by FxRate again.
+        var first = await sut.GetTransactionAsync(id);
-        var first = sut.GetTransaction(id);
+        var second = await sut.GetTransactionAsync(id);
-        var second = sut.GetTransaction(id);
 
         first.ShouldNotBeNull();
         first.Value.ShouldBe(100m);
@@ -125,24 +123,24 @@ public class TransactionRepositoryTestShould : IDisposable
     }
 
     [Fact]
-    public void RemoveTransactionWhenDeletingById()
+    public async Task RemoveTransactionWhenDeletingById()
     {
-        accountRepo.GetAccount(Arg.Any<string>()).Returns(new Account { Currency = "CHF" });
+        accountRepo.GetAccountAsync(Arg.Any<string>()).Returns(new Account { Currency = "CHF" });
 
-        sut.SaveTransaction(new Transaction { OriginAccountId = "a", TargetAccountId = "b", Value = 1m, Text = "x", ValueDate = DateTime.Today });
+        await sut.SaveTransactionAsync(new Transaction { OriginAccountId = "a", TargetAccountId = "b", Value = 1m, Text = "x", ValueDate = DateTime.Today });
-        var id = sut.GetTransactionList().Single().Id;
+        var id = (await sut.GetTransactionListAsync()).Single().Id;
 
-        sut.DeleteTransaction(id);
+        await sut.DeleteTransactionAsync(id);
 
-        sut.GetTransactionList().ShouldBeEmpty();
+        (await sut.GetTransactionListAsync()).ShouldBeEmpty();
     }
 
     [Fact]
-    public void PreserveRelatedPartyWhenRoundTrippingTransaction()
+    public async Task PreserveRelatedPartyWhenRoundTrippingTransaction()
     {
-        accountRepo.GetAccount(Arg.Any<string>()).Returns(new Account { Currency = "CHF" });
+        accountRepo.GetAccountAsync(Arg.Any<string>()).Returns(new Account { Currency = "CHF" });
 
-        sut.SaveTransaction(new Transaction
+        await sut.SaveTransactionAsync(new Transaction
         {
             OriginAccountId = "a",
             TargetAccountId = "b",
@@ -153,26 +151,23 @@ public class TransactionRepositoryTestShould : IDisposable
             BookingDate = new DateTime(2026, 4, 1)
         });
 
-        // Regression: earlier Transaction.Copy dropped RelatedParty on every save,
+        (await sut.GetTransactionListAsync()).Single().RelatedParty.ShouldBe("ACME Property AG");
-        // so the round-trip lost it.
-        sut.GetTransactionList().Single().RelatedParty.ShouldBe("ACME Property AG");
     }
 
     [Fact]
-    public void DefaultBookingDateToValueDateWhenBookingDateIsUnset()
+    public async Task DefaultBookingDateToValueDateWhenBookingDateIsUnset()
     {
-        accountRepo.GetAccount(Arg.Any<string>()).Returns(new Account { Currency = "CHF" });
+        accountRepo.GetAccountAsync(Arg.Any<string>()).Returns(new Account { Currency = "CHF" });
 
-        sut.SaveTransaction(new Transaction
+        await sut.SaveTransactionAsync(new Transaction
         {
             OriginAccountId = "a",
             TargetAccountId = "b",
             Value = 10m,
             Text = "x",
             ValueDate = new DateTime(2026, 4, 15)
-            // BookingDate left at default (DateTime.MinValue)
         });
 
-        sut.GetTransactionList().Single().BookingDate.ShouldBe(new DateTime(2026, 4, 15));
+        (await sut.GetTransactionListAsync()).Single().BookingDate.ShouldBe(new DateTime(2026, 4, 15));
     }
 }

Schaad.Accounting.Tests/ViewServiceTestShould.cs

@@ -18,12 +18,10 @@ public class ViewServiceTestShould
 
     public ViewServiceTestShould()
     {
-        // Cover every subclass number a test might reference (Account.SubClass = Number / 100).
+        subclassRepo.GetSubClassListAsync().Returns(
-        subclassRepo.GetSubClassList().Returns(
             Enumerable.Range(10, 50).Select(n => new SubClass { Number = n, Name = "sub-" + n }).ToList());
         subclassRepo.GetClass(Arg.Any<int>()).Returns("");
 
-        // Passthrough FX by default (CHF-only). Individual tests can override.
         fxConverter.ConvertToChf(Arg.Any<decimal>(), Arg.Any<string>())
             .Returns(ci => ci.ArgAt<decimal>(0));
     }
@@ -34,16 +32,16 @@ public class ViewServiceTestShould
     // --- Balance math ---------------------------------------------------------
 
     [Fact]
-    public void SumActivaAndPassivaTotalsSeparatelyWhenGettingBalanceView()
+    public async Task SumActivaAndPassivaTotalsSeparatelyWhenGettingBalanceView()
     {
         var cash = Account("cash", 1000, "CHF", startBalance: 100m);
         var receivables = Account("recv", 1100, "CHF", startBalance: 50m);
         var payables = Account("pay", 2000, "CHF", startBalance: -200m);
 
-        accountRepo.GetAccountList().Returns(new List<Account> { cash, receivables, payables });
+        accountRepo.GetAccountListAsync().Returns(new List<Account> { cash, receivables, payables });
-        transactionRepo.GetTransactionList().Returns(new List<Transaction>());
+        transactionRepo.GetTransactionListAsync().Returns(new List<Transaction>());
 
-        var view = BuildService().GetBalanceView();
+        var view = await BuildService().GetBalanceViewAsync();
 
         view.ActivaAccountList.Count.ShouldBe(2);
         view.PassivaAccountList.Count.ShouldBe(1);
@@ -52,109 +50,105 @@ public class ViewServiceTestShould
     }
 
     [Fact]
-    public void ApplyTransactionsToStartBalanceWhenComputingAccountBalance()
+    public async Task ApplyTransactionsToStartBalanceWhenComputingAccountBalance()
     {
         var cash = Account("cash", 1000, "CHF", startBalance: 1000m);
         var groceries = Account("groc", 4000, "CHF");
-        accountRepo.GetAccountList().Returns(new List<Account> { cash, groceries });
+        accountRepo.GetAccountListAsync().Returns(new List<Account> { cash, groceries });
 
-        // Debit cash 50, credit groceries 50 (spending)
+        transactionRepo.GetTransactionListAsync().Returns(new List<Transaction>
-        transactionRepo.GetTransactionList().Returns(new List<Transaction>
         {
             new() { Id = "t1", OriginAccountId = "cash", TargetAccountId = "groc", Value = 50m, ValueDate = new DateTime(2026, 1, 1) },
             new() { Id = "t2", OriginAccountId = "cash", TargetAccountId = "groc", Value = 30m, ValueDate = new DateTime(2026, 1, 2) },
         });
 
-        var accounts = BuildService().GetAccountViewList();
+        var accounts = await BuildService().GetAccountViewListAsync();
 
-        accounts.Single(a => a.Id == "cash").Balance.ShouldBe(920m); // 1000 - 80
+        accounts.Single(a => a.Id == "cash").Balance.ShouldBe(920m);
         accounts.Single(a => a.Id == "groc").Balance.ShouldBe(80m);
     }
 
     [Fact]
-    public void ConvertBalanceToChfWhenAccountUsesForeignCurrency()
+    public async Task ConvertBalanceToChfWhenAccountUsesForeignCurrency()
     {
         var usd = Account("usd", 1050, "USD", startBalance: 100m);
-        accountRepo.GetAccountList().Returns(new List<Account> { usd });
+        accountRepo.GetAccountListAsync().Returns(new List<Account> { usd });
-        transactionRepo.GetTransactionList().Returns(new List<Transaction>());
+        transactionRepo.GetTransactionListAsync().Returns(new List<Transaction>());
 
-        // 1 USD = 0.90 CHF
         fxConverter.ConvertToChf(Arg.Any<decimal>(), "USD")
             .Returns(ci => ci.ArgAt<decimal>(0) * 0.9m);
 
-        var account = BuildService().GetAccountViewList().Single();
+        var account = (await BuildService().GetAccountViewListAsync()).Single();
 
-        account.Balance.ShouldBe(100m);         // account currency
+        account.Balance.ShouldBe(100m);
-        account.BalanceCHF.ShouldBe(90m);       // FX-converted
+        account.BalanceCHF.ShouldBe(90m);
         account.StartBalanceCHF.ShouldBe(90m);
     }
 
     // --- Bank-transaction auto-matching --------------------------------------
 
     [Fact]
-    public void MatchBankTransactionByBookingRuleWhenLookupTextIsContained()
+    public async Task MatchBankTransactionByBookingRuleWhenLookupTextIsContained()
     {
         var checking = Account("chk", 1010, "CHF", bankAccountNumber: "CH01");
         var utilities = Account("util", 4200, "CHF");
-        accountRepo.GetAccountList().Returns(new List<Account> { checking, utilities });
+        accountRepo.GetAccountListAsync().Returns(new List<Account> { checking, utilities });
-        bookingRuleRepo.GetBookingRuleList().Returns(new List<BookingRule>
+        bookingRuleRepo.GetBookingRuleListAsync().Returns(new List<BookingRule>
         {
             new() { Id = "r1", LookupText = "electric", AccountId = "util", BookingText = "Strom" }
         });
-        bankTransactionRepo.GetBankTransactionList().Returns(new List<BankTransaction>
+        bankTransactionRepo.GetBankTransactionListAsync().Returns(new List<BankTransaction>
         {
             new() { Id = "b1", Text = "Monthly Electric Bill", Value = -85m, BankAccountNumber = "CH01",
                     ValueDate = new DateTime(2026, 3, 5), BookingDate = new DateTime(2026, 3, 5) }
         });
-        transactionRepo.GetTransactionList().Returns(new List<Transaction>());
+        transactionRepo.GetTransactionListAsync().Returns(new List<Transaction>());
 
-        var matched = BuildService().MatchOpenBankTransactions().Single();
+        var matched = (await BuildService().MatchOpenBankTransactionsAsync()).Single();
 
         matched.Text.ShouldBe("Strom");
-        // negative value => bank account is origin; rule fills the target
         matched.OriginAccountId.ShouldBe("chk");
         matched.TargetAccountId.ShouldBe("util");
     }
 
     [Fact]
-    public void PreferBookingRuleWithMatchingValueWhenMultipleRulesMatchText()
+    public async Task PreferBookingRuleWithMatchingValueWhenMultipleRulesMatchText()
     {
         var checking = Account("chk", 1010, "CHF", bankAccountNumber: "CH01");
         var rent = Account("rent", 4100, "CHF");
         var groceries = Account("groc", 4200, "CHF");
-        accountRepo.GetAccountList().Returns(new List<Account> { checking, rent, groceries });
+        accountRepo.GetAccountListAsync().Returns(new List<Account> { checking, rent, groceries });
-        bookingRuleRepo.GetBookingRuleList().Returns(new List<BookingRule>
+        bookingRuleRepo.GetBookingRuleListAsync().Returns(new List<BookingRule>
         {
             new() { Id = "r1", LookupText = "coop", LookupValue = 0m, AccountId = "groc", BookingText = "Groceries" },
             new() { Id = "r2", LookupText = "coop", LookupValue = 1200m, AccountId = "rent", BookingText = "Rent via Coop" }
         });
-        bankTransactionRepo.GetBankTransactionList().Returns(new List<BankTransaction>
+        bankTransactionRepo.GetBankTransactionListAsync().Returns(new List<BankTransaction>
         {
             new() { Id = "b1", Text = "COOP payment", Value = -1200m, BankAccountNumber = "CH01",
                     ValueDate = new DateTime(2026, 3, 1), BookingDate = new DateTime(2026, 3, 1) }
         });
-        transactionRepo.GetTransactionList().Returns(new List<Transaction>());
+        transactionRepo.GetTransactionListAsync().Returns(new List<Transaction>());
 
-        var matched = BuildService().MatchOpenBankTransactions().Single();
+        var matched = (await BuildService().MatchOpenBankTransactionsAsync()).Single();
 
         matched.Text.ShouldBe("Rent via Coop");
         matched.TargetAccountId.ShouldBe("rent");
     }
 
     [Fact]
-    public void FallBackToSameAccountsLastMonthWhenNoBookingRuleMatches()
+    public async Task FallBackToSameAccountsLastMonthWhenNoBookingRuleMatches()
     {
         var checking = Account("chk", 1010, "CHF", bankAccountNumber: "CH01");
         var salary = Account("sal", 3000, "CHF");
-        accountRepo.GetAccountList().Returns(new List<Account> { checking, salary });
+        accountRepo.GetAccountListAsync().Returns(new List<Account> { checking, salary });
-        bookingRuleRepo.GetBookingRuleList().Returns(new List<BookingRule>());
+        bookingRuleRepo.GetBookingRuleListAsync().Returns(new List<BookingRule>());
-        bankTransactionRepo.GetBankTransactionList().Returns(new List<BankTransaction>
+        bankTransactionRepo.GetBankTransactionListAsync().Returns(new List<BankTransaction>
         {
             new() { Id = "b2", Text = "Salary Feb", Value = 5000m, BankAccountNumber = "CH01",
                     ValueDate = new DateTime(2026, 2, 25), BookingDate = new DateTime(2026, 2, 25) }
         });
-        // A prior-month booking with same accounts + value should be picked up
+        transactionRepo.GetTransactionListAsync().Returns(new List<Transaction>
-        transactionRepo.GetTransactionList().Returns(new List<Transaction>
         {
             new()
             {
@@ -168,33 +162,31 @@ public class ViewServiceTestShould
             }
         });
 
-        var matched = BuildService().MatchOpenBankTransactions().Single();
+        var matched = (await BuildService().MatchOpenBankTransactionsAsync()).Single();
 
         matched.Text.ShouldBe("Monatslohn");
     }
 
     [Fact]
-    public void ExcludeIgnoredAndAlreadyBookedWhenGettingOpenBankTransactions()
+    public async Task ExcludeIgnoredAndAlreadyBookedWhenGettingOpenBankTransactions()
     {
-        bankTransactionRepo.GetBankTransactionList().Returns(new List<BankTransaction>
+        bankTransactionRepo.GetBankTransactionListAsync().Returns(new List<BankTransaction>
         {
             new() { Id = "open", Text = "still open", Ignore = false },
             new() { Id = "ignored", Text = "ignore me", Ignore = true },
             new() { Id = "booked", Text = "already booked", Ignore = false }
         });
-        transactionRepo.GetTransactionList().Returns(new List<Transaction>
+        transactionRepo.GetTransactionListAsync().Returns(new List<Transaction>
         {
             new() { Id = "t1", BankTransactionId = "booked", OriginAccountId = "a", TargetAccountId = "b", Value = 10 }
         });
 
-        var open = BuildService().GetOpenBankTransactionList();
+        var open = await BuildService().GetOpenBankTransactionListAsync();
 
         open.Count.ShouldBe(1);
         open[0].Id.ShouldBe("open");
     }
 
-    // --- Helpers -------------------------------------------------------------
-
     private static Account Account(string id, int number, string currency, decimal startBalance = 0m, string? bankAccountNumber = null)
         => new()
         {

Schaad.Accounting.UI/Components/Pages/Accounts.razor.cs

@@ -1,4 +1,4 @@
-using Microsoft.AspNetCore.Components;
+using Microsoft.AspNetCore.Components;
 using Microsoft.FluentUI.AspNetCore.Components;
 using Schaad.Accounting.Interfaces;
 using Schaad.Accounting.Models;
@@ -8,7 +8,7 @@ namespace Schaad.Accounting.UI.Components.Pages;
 
 public partial class Accounts : ComponentBase
 {
-     [Inject]
+    [Inject]
     private IAccountRepository accountRepository { get; set; } = null!;
 
     [Inject]
@@ -16,10 +16,10 @@ public partial class Accounts : ComponentBase
 
     private IQueryable<Account>? accountQueryable;
 
-    protected override Task OnInitializedAsync()  
+    protected override async Task OnInitializedAsync()
     {
-        accountQueryable = accountRepository.GetAccountList().AsQueryable();  
+        accountQueryable = (await accountRepository.GetAccountListAsync()).AsQueryable();
-        return base.OnInitializedAsync();  
+        await base.OnInitializedAsync();
     }
 
     private async Task AddAsync()
@@ -36,13 +36,13 @@ public partial class Accounts : ComponentBase
         var result = await dialog.Result;
         if (!result.Cancelled && result.Data != null)
         {
-            accountQueryable = accountRepository.GetAccountList().AsQueryable();  
+            accountQueryable = (await accountRepository.GetAccountListAsync()).AsQueryable();
         }
     }
 
     private async Task EditAsync(string id)
     {
-        var data = accountRepository.GetAccount(id);
+        var data = await accountRepository.GetAccountAsync(id);
         var dialog = await dialogService.ShowDialogAsync<AccountDialog>(data, new DialogParameters()
         {
             Height = "500px",
@@ -54,19 +54,19 @@ public partial class Accounts : ComponentBase
         var result = await dialog.Result;
         if (!result.Cancelled && result.Data != null)
         {
-            accountQueryable = accountRepository.GetAccountList().AsQueryable();  
+            accountQueryable = (await accountRepository.GetAccountListAsync()).AsQueryable();
         }
     }
 
     private async Task DeleteAsync(string id)
     {
-        var account = accountRepository.GetAccount(id);
+        var account = await accountRepository.GetAccountAsync(id);
         var dialog = await dialogService.ShowConfirmationAsync($"Konto '{account.Name}' wirklich löschen?", "Ja", "Nein", "Konto löschen");
         var result = await dialog.Result;
         if (!result.Cancelled)
         {
-            accountRepository.DeleteAccount(id);
+            await accountRepository.DeleteAccountAsync(id);
-            accountQueryable = accountRepository.GetAccountList().AsQueryable();  
+            accountQueryable = (await accountRepository.GetAccountListAsync()).AsQueryable();
         }
     }
 }

Schaad.Accounting.UI/Components/Pages/BankTransactions.razor.cs

@@ -1,4 +1,4 @@
-using Microsoft.AspNetCore.Components;
+using Microsoft.AspNetCore.Components;
 using Schaad.Accounting.Interfaces;
 using Schaad.Accounting.Models;
 
@@ -10,9 +10,9 @@ public partial class BankTransactions : ComponentBase
     private IBankTransactionRepository bankTransactionRepository { get; set; } = null!;
     private IQueryable<BankTransaction>? TransactionList;
 
-    protected override Task OnInitializedAsync()  
+    protected override async Task OnInitializedAsync()
     {
-        TransactionList = bankTransactionRepository.GetBankTransactionList().AsQueryable();  
+        TransactionList = (await bankTransactionRepository.GetBankTransactionListAsync()).AsQueryable();
-        return base.OnInitializedAsync();  
+        await base.OnInitializedAsync();
     }
 }

Schaad.Accounting.UI/Components/Pages/BookingRules.razor.cs

@@ -1,4 +1,4 @@
-using Microsoft.AspNetCore.Components;
+using Microsoft.AspNetCore.Components;
 using Microsoft.FluentUI.AspNetCore.Components;
 using Schaad.Accounting.Datasets;
 using Schaad.Accounting.Interfaces;
@@ -20,10 +20,10 @@ public partial class BookingRules : ComponentBase
 
     private IQueryable<BookingRuleDataset>? bookingRulesQueryable;
 
-    protected override Task OnInitializedAsync()  
+    protected override async Task OnInitializedAsync()
     {
-        bookingRulesQueryable = viewService.GetBookingRuleViewList().AsQueryable();  
+        bookingRulesQueryable = (await viewService.GetBookingRuleViewListAsync()).AsQueryable();
-        return base.OnInitializedAsync();  
+        await base.OnInitializedAsync();
     }
 
     private async Task AddAsync()
@@ -40,13 +40,13 @@ public partial class BookingRules : ComponentBase
         var result = await dialog.Result;
         if (!result.Cancelled && result.Data != null)
         {
-            bookingRulesQueryable = viewService.GetBookingRuleViewList().AsQueryable();
+            bookingRulesQueryable = (await viewService.GetBookingRuleViewListAsync()).AsQueryable();
         }
     }
 
     private async Task EditAsync(string id)
     {
-        var data = bookingRuleRepository.GetBookingRule(id);
+        var data = await bookingRuleRepository.GetBookingRuleAsync(id);
         var dialog = await dialogService.ShowDialogAsync<BookingRuleDialog>(data, new DialogParameters()
         {
             Height = "500px",
@@ -58,19 +58,19 @@ public partial class BookingRules : ComponentBase
         var result = await dialog.Result;
         if (!result.Cancelled && result.Data != null)
         {
-            bookingRulesQueryable = viewService.GetBookingRuleViewList().AsQueryable();
+            bookingRulesQueryable = (await viewService.GetBookingRuleViewListAsync()).AsQueryable();
         }
     }
 
     private async Task DeleteAsync(string id)
     {
-        var bookingRule = bookingRuleRepository.GetBookingRule(id);
+        var bookingRule = await bookingRuleRepository.GetBookingRuleAsync(id);
         var dialog = await dialogService.ShowConfirmationAsync($"Regel '{bookingRule.LookupText}' wirklich löschen?", "Ja", "Nein", "Buchungsregel löschen");
         var result = await dialog.Result;
         if (!result.Cancelled)
         {
-            bookingRuleRepository.DeleteBookingRule(id);
+            await bookingRuleRepository.DeleteBookingRuleAsync(id);
-            bookingRulesQueryable = viewService.GetBookingRuleViewList().AsQueryable();
+            bookingRulesQueryable = (await viewService.GetBookingRuleViewListAsync()).AsQueryable();
         }
     }
 }

Schaad.Accounting.UI/Components/Pages/BookingTexts.razor.cs

@@ -1,4 +1,4 @@
-using Microsoft.AspNetCore.Components;
+using Microsoft.AspNetCore.Components;
 using Microsoft.FluentUI.AspNetCore.Components;
 using Schaad.Accounting.Interfaces;
 using Schaad.Accounting.Models;
@@ -16,10 +16,10 @@ public partial class BookingTexts : ComponentBase
 
     private IQueryable<BookingText>? bookingTextQueryable;
 
-    protected override Task OnInitializedAsync()  
+    protected override async Task OnInitializedAsync()
     {
-        bookingTextQueryable = bookingTextRepository.GetBookingTextList().AsQueryable();  
+        bookingTextQueryable = (await bookingTextRepository.GetBookingTextListAsync()).AsQueryable();
-        return base.OnInitializedAsync();  
+        await base.OnInitializedAsync();
     }
 
     private async Task AddAsync()
@@ -36,13 +36,13 @@ public partial class BookingTexts : ComponentBase
         var result = await dialog.Result;
         if (!result.Cancelled && result.Data != null)
         {
-            bookingTextQueryable = bookingTextRepository.GetBookingTextList().AsQueryable();
+            bookingTextQueryable = (await bookingTextRepository.GetBookingTextListAsync()).AsQueryable();
         }
     }
 
     private async Task EditAsync(string id)
     {
-        var data = bookingTextRepository.GetBookingText(id);
+        var data = await bookingTextRepository.GetBookingTextAsync(id);
         var dialog = await dialogService.ShowDialogAsync<BookingTextDialog>(data, new DialogParameters()
         {
             Height = "500px",
@@ -54,19 +54,19 @@ public partial class BookingTexts : ComponentBase
         var result = await dialog.Result;
         if (!result.Cancelled && result.Data != null)
         {
-            bookingTextQueryable = bookingTextRepository.GetBookingTextList().AsQueryable();
+            bookingTextQueryable = (await bookingTextRepository.GetBookingTextListAsync()).AsQueryable();
         }
     }
 
     private async Task DeleteAsync(string id)
     {
-        var bookingText = bookingTextRepository.GetBookingText(id);
+        var bookingText = await bookingTextRepository.GetBookingTextAsync(id);
         var dialog = await dialogService.ShowConfirmationAsync($"Buchungstext '{bookingText.Text}' wirklich löschen?", "Ja", "Nein", "Buchungstext löschen");
         var result = await dialog.Result;
         if (!result.Cancelled)
         {
-            bookingTextRepository.DeleteBookingText(id);
+            await bookingTextRepository.DeleteBookingTextAsync(id);
-            bookingTextQueryable = bookingTextRepository.GetBookingTextList().AsQueryable();
+            bookingTextQueryable = (await bookingTextRepository.GetBookingTextListAsync()).AsQueryable();
         }
     }
 }

Schaad.Accounting.UI/Components/Pages/Charts/Assets.razor

@@ -3,4 +3,7 @@
 
 <PageTitle>Ausgaben</PageTitle>
 
-<PlotlyChart style="height: 700px; min-height: 500px" @bind-Config="config" @bind-Layout="layout" @bind-Data="data" @ref="chart" />
+@if (config is not null && layout is not null && data is not null)
+{
+    <PlotlyChart style="height: 700px; min-height: 500px" @bind-Config="config" @bind-Layout="layout" @bind-Data="data" @ref="chart" />
+}

Schaad.Accounting.UI/Components/Pages/Charts/Assets.razor.cs

@@ -8,14 +8,14 @@ namespace Schaad.Accounting.UI.Components.Pages.Charts;
 public partial class Assets : ComponentBase
 {
     private PlotlyChart chart = null!;
-    private Config config = null!;
+    private Config? config;
-    private Plotly.Blazor.Layout layout = null!;
+    private Plotly.Blazor.Layout? layout;
-    private IList<ITrace> data = null!;
+    private IList<ITrace>? data;
     
     [Inject]
     private IViewService viewService { get; set; } = null!;
     
-    protected override Task OnInitializedAsync()
+    protected override async Task OnInitializedAsync()
     {
         config = new Config
         {
@@ -26,7 +26,7 @@ public partial class Assets : ComponentBase
         {
         };
 
-        var accounts = viewService.GetAccountViewList().Where(a => a.Class == ClassIds.Activa);
+        var accounts = (await viewService.GetAccountViewListAsync()).Where(a => a.Class == ClassIds.Activa);
         var values = new List<object>();
         var labels = new List<object>();
         var ids = new List<object>();
@@ -50,6 +50,6 @@ public partial class Assets : ComponentBase
             }
         };
 
-        return base.OnInitializedAsync();  
+        await base.OnInitializedAsync();
     }
 }

Schaad.Accounting.UI/Components/Pages/Charts/Spendings.razor

@@ -3,4 +3,7 @@
 
 <PageTitle>Ausgaben</PageTitle>
 
-<PlotlyChart style="height: 700px; min-height: 500px" @bind-Config="config" @bind-Layout="layout" @bind-Data="data" @ref="chart" />
+@if (config is not null && layout is not null && data is not null)
+{
+    <PlotlyChart style="height: 700px; min-height: 500px" @bind-Config="config" @bind-Layout="layout" @bind-Data="data" @ref="chart" />
+}

Schaad.Accounting.UI/Components/Pages/Charts/Spendings.razor.cs

@@ -8,14 +8,14 @@ namespace Schaad.Accounting.UI.Components.Pages.Charts;
 public partial class Spendings : ComponentBase
 {
     private PlotlyChart chart = null!;
-    private Config config = null!;
+    private Config? config;
-    private Plotly.Blazor.Layout layout = null!;
+    private Plotly.Blazor.Layout? layout;
-    private IList<ITrace> data = null!;
+    private IList<ITrace>? data;
     
     [Inject]
     private IViewService viewService { get; set; } = null!;
     
-    protected override Task OnInitializedAsync()
+    protected override async Task OnInitializedAsync()
     {
         config = new Config
         {
@@ -26,7 +26,7 @@ public partial class Spendings : ComponentBase
         {
         };
 
-        var accounts = viewService.GetAccountViewList().Where(a => a.Class == ClassIds.Expenses);
+        var accounts = (await viewService.GetAccountViewListAsync()).Where(a => a.Class == ClassIds.Expenses);
         var values = new List<object>();
         var labels = new List<object>();
         foreach (var grp in accounts.GroupBy(a => a.SubClass).Select(a => new {Key = a.Key, List = a.ToList()}))
@@ -47,6 +47,6 @@ public partial class Spendings : ComponentBase
             }
         };
 
-        return base.OnInitializedAsync();  
+        await base.OnInitializedAsync();
     }
 }

Schaad.Accounting.UI/Components/Pages/Charts/SpendingsOverTime.razor

@@ -3,4 +3,7 @@
 
 <PageTitle>Ausgaben im Verlauf</PageTitle>
 
-<PlotlyChart style="height: 700px; min-height: 500px" @bind-Config="config" @bind-Layout="layout" @bind-Data="data" @ref="chart" />
+@if (config is not null && layout is not null)
+{
+    <PlotlyChart style="height: 700px; min-height: 500px" @bind-Config="config" @bind-Layout="layout" @bind-Data="data" @ref="chart" />
+}

Schaad.Accounting.UI/Components/Pages/Charts/SpendingsOverTime.razor.cs

@@ -9,14 +9,14 @@ namespace Schaad.Accounting.UI.Components.Pages.Charts;
 public partial class SpendingsOverTime : ComponentBase
 {
     private PlotlyChart chart = null!;
-    private Config config = null!;
+    private Config? config;
-    private Plotly.Blazor.Layout layout = null!;
+    private Plotly.Blazor.Layout? layout;
     private IList<ITrace> data = new List<ITrace>();
     
     [Inject]
     private IChartService chartService { get; set; } = null!;
     
-    protected override Task OnInitializedAsync()
+    protected override async Task OnInitializedAsync()
     {
         config = new Config
         {
@@ -44,7 +44,7 @@ public partial class SpendingsOverTime : ComponentBase
         };
         
 
-        var dataSeries = chartService.GetExpensesPerMonth();
+        var dataSeries = await chartService.GetExpensesPerMonthAsync();
         foreach (var dataSerie in dataSeries)
         {
             data.Add(new Bar
@@ -55,6 +55,6 @@ public partial class SpendingsOverTime : ComponentBase
             });
         };
 
-        return base.OnInitializedAsync();  
+        await base.OnInitializedAsync();
     }
 }

Schaad.Accounting.UI/Components/Pages/Classes.razor.cs

@@ -1,4 +1,4 @@
-using Microsoft.AspNetCore.Components;
+using Microsoft.AspNetCore.Components;
 using Microsoft.FluentUI.AspNetCore.Components;
 using Schaad.Accounting.Interfaces;
 using Schaad.Accounting.Models;
@@ -16,10 +16,10 @@ public partial class Classes : ComponentBase
 
     private IQueryable<SubClass>? subclassQueryable;
 
-    protected override Task OnInitializedAsync()  
+    protected override async Task OnInitializedAsync()
     {
-        subclassQueryable = subclassRepository.GetSubClassList().AsQueryable();  
+        subclassQueryable = (await subclassRepository.GetSubClassListAsync()).AsQueryable();
-        return base.OnInitializedAsync();  
+        await base.OnInitializedAsync();
     }
 
     private async Task AddAsync()
@@ -36,13 +36,13 @@ public partial class Classes : ComponentBase
         var result = await dialog.Result;
         if (!result.Cancelled && result.Data != null)
         {
-            subclassQueryable = subclassRepository.GetSubClassList().AsQueryable();  
+            subclassQueryable = (await subclassRepository.GetSubClassListAsync()).AsQueryable();
         }
     }
 
     private async Task EditAsync(string id)
     {
-        var data = subclassRepository.GetSubClass(id);
+        var data = await subclassRepository.GetSubClassAsync(id);
         var dialog = await dialogService.ShowDialogAsync<ClassDialog>(data, new DialogParameters()
         {
             Height = "500px",
@@ -54,19 +54,19 @@ public partial class Classes : ComponentBase
         var result = await dialog.Result;
         if (!result.Cancelled && result.Data != null)
         {
-            subclassQueryable = subclassRepository.GetSubClassList().AsQueryable(); 
+            subclassQueryable = (await subclassRepository.GetSubClassListAsync()).AsQueryable();
         }
     }
 
     private async Task DeleteAsync(string id)
     {
-        var subclass = subclassRepository.GetSubClass(id);
+        var subclass = await subclassRepository.GetSubClassAsync(id);
         var dialog = await dialogService.ShowConfirmationAsync($"Klasse '{subclass.Name}' wirklich löschen?", "Ja", "Nein", "Klasse löschen");
         var result = await dialog.Result;
         if (!result.Cancelled)
         {
-            subclassRepository.DeleteSubClass(id);
+            await subclassRepository.DeleteSubClassAsync(id);
-            subclassQueryable = subclassRepository.GetSubClassList().AsQueryable(); 
+            subclassQueryable = (await subclassRepository.GetSubClassListAsync()).AsQueryable();
         }
     }
 }

Schaad.Accounting.UI/Components/Pages/Dialogs/AccountDialog.razor.cs

@@ -28,7 +28,7 @@ public partial class AccountDialog : ComponentBase
     {
         if (editContext.Validate())
         {
-            accountRepository.SaveAccount(Content);
+            await accountRepository.SaveAccountAsync(Content);
             await Dialog.CloseAsync(Content);
         }
     }

Schaad.Accounting.UI/Components/Pages/Dialogs/BookingRuleDialog.razor

@@ -12,6 +12,12 @@
 </FluentDialogHeader>
 
 <FluentDialogBody>
+    @if (editContext is null)
+    {
+        <p>Lädt…</p>
+        return;
+    }
+
     <EditForm EditContext="@editContext">
         <DataAnnotationsValidator />
         <FluentTextField @bind-Value="@Content.LookupText" Label="Suchtext" Style="width: 300px;"/>

Schaad.Accounting.UI/Components/Pages/Dialogs/BookingRuleDialog.razor.cs

@@ -8,7 +8,7 @@ namespace Schaad.Accounting.UI.Components.Pages.Dialogs;
 
 public partial class BookingRuleDialog : ComponentBase
 {
-    private EditContext editContext = null!;
+    private EditContext? editContext;
 
     [CascadingParameter]
     public FluentDialog Dialog { get; set; } = null!;
@@ -24,17 +24,17 @@ public partial class BookingRuleDialog : ComponentBase
 
     private IReadOnlyList<Account> accounts = [];
 
-    protected override void OnInitialized()
+    protected override async Task OnInitializedAsync()
     {
         editContext = new EditContext(Content);
-        accounts = viewService.GetAccountViewList();
+        accounts = await viewService.GetAccountViewListAsync();
     }
 
     private async Task SaveAsync()
     {
         if (editContext.Validate())
         {
-            bookingRuleRepository.SaveBookingRule(Content);
+            await bookingRuleRepository.SaveBookingRuleAsync(Content);
             await Dialog.CloseAsync(Content);
         }
     }

Schaad.Accounting.UI/Components/Pages/Dialogs/BookingTextDialog.razor.cs

@@ -28,7 +28,7 @@ public partial class BookingTextDialog : ComponentBase
     {
         if (editContext.Validate())
         {
-            bookingTextRepository.SaveBookingText(Content);
+            await bookingTextRepository.SaveBookingTextAsync(Content);
             await Dialog.CloseAsync(Content);
         }
     }

Schaad.Accounting.UI/Components/Pages/Dialogs/ClassDialog.razor.cs

@@ -28,7 +28,7 @@ public partial class ClassDialog : ComponentBase
     {
         if (editContext.Validate())
         {
-            bookingRuleRepository.SaveSubClass(Content);
+            await bookingRuleRepository.SaveSubClassAsync(Content);
             await Dialog.CloseAsync(Content);
         }
     }

Schaad.Accounting.UI/Components/Pages/Dialogs/TransactionDialog.razor

@@ -11,6 +11,12 @@
 </FluentDialogHeader>
 
 <FluentDialogBody>
+    @if (editContext is null)
+    {
+        <p>Lädt…</p>
+        return;
+    }
+
     <EditForm EditContext="@editContext">
         <DataAnnotationsValidator />
         <FluentDatePicker @bind-Value="@SelectedValue" Label="Valuta" Style="width: 300px;"/>

Schaad.Accounting.UI/Components/Pages/Dialogs/TransactionDialog.razor.cs

@@ -8,7 +8,7 @@ namespace Schaad.Accounting.UI.Components.Pages.Dialogs;
 
 public partial class TransactionDialog : ComponentBase
 {
-    private EditContext editContext = null!;
+    private EditContext? editContext;
 
     [CascadingParameter]
     public FluentDialog Dialog { get; set; } = null!;
@@ -25,11 +25,11 @@ public partial class TransactionDialog : ComponentBase
     private IReadOnlyList<Account> accounts = [];
     private DateTime? SelectedValue;
 
-    protected override void OnInitialized()
+    protected override async Task OnInitializedAsync()
     {
         SelectedValue = Content.ValueDate;
         editContext = new EditContext(Content);
-        accounts = viewService.GetAccountViewList();
+        accounts = await viewService.GetAccountViewListAsync();
     }
 
     private async Task SaveAsync()
@@ -38,7 +38,7 @@ public partial class TransactionDialog : ComponentBase
         {
             Content.ValueDate = SelectedValue!.Value;
             Content.BookingDate = SelectedValue!.Value;
-            transactionRepository.SaveTransaction(Content);
+            await transactionRepository.SaveTransactionAsync(Content);
             await Dialog.CloseAsync(Content);
         }
     }

Schaad.Accounting.UI/Components/Pages/Dialogs/TransactionSplitDialog.razor

@@ -11,6 +11,12 @@
 </FluentDialogHeader>
 
 <FluentDialogBody>
+    @if (editContext is null)
+    {
+        <p>Lädt…</p>
+        return;
+    }
+
     Total: @Math.Abs(Content.Value) / Rest: @openAmount
     <FluentButton Appearance="Appearance.Neutral" IconEnd="@(new Icons.Regular.Size24.Add())"
                   OnClick="@AddTransactionAsync">

Schaad.Accounting.UI/Components/Pages/Dialogs/TransactionSplitDialog.razor.cs

@@ -9,7 +9,7 @@ namespace Schaad.Accounting.UI.Components.Pages.Dialogs;
 
 public partial class TransactionSplitDialog : ComponentBase
 {
-    private EditContext editContext = null!;
+    private EditContext? editContext;
 
     [CascadingParameter]
     public FluentDialog Dialog { get; set; } = null!;
@@ -33,17 +33,17 @@ public partial class TransactionSplitDialog : ComponentBase
     private IViewService viewService { get; set; } = null!;
     
     private List<Transaction> transactionList = new();
-    private IReadOnlyList<AccountDataset> accounts = null!;
+    private IReadOnlyList<AccountDataset> accounts = [];
     private IReadOnlyList<string> bookingTexts = [];
     private decimal openAmount = 0;
     
 
-    protected override void OnInitialized()
+    protected override async Task OnInitializedAsync()
     {
-        accounts = viewService.GetAccountViewList();
+        accounts = await viewService.GetAccountViewListAsync();
-        bookingTexts = bookingTextRepository.GetBookingTextList().Select(b => b.Text).ToArray();
+        bookingTexts = (await bookingTextRepository.GetBookingTextListAsync()).Select(b => b.Text).ToArray();
-        var accountList = accountRepository.GetAccountList();
+        var accountList = await accountRepository.GetAccountListAsync();
-        var bankTrx = bankTransactionRepository.GetBankTransaction(Content.BankTransactionId);
+        var bankTrx = await bankTransactionRepository.GetBankTransactionAsync(Content.BankTransactionId);
         var trx = new Transaction(bankTrx, accountList);
         trx.Value = Math.Abs(bankTrx.Value);
         transactionList.Add(trx);
@@ -74,7 +74,7 @@ public partial class TransactionSplitDialog : ComponentBase
         {
             foreach (var transtaction in transactionList)
             {
-                transactionRepository.SaveTransaction(transtaction);
+                await transactionRepository.SaveTransactionAsync(transtaction);
             }
             await Dialog.CloseAsync(Content);
         }

Schaad.Accounting.UI/Components/Pages/Home.razor.cs

@@ -44,12 +44,12 @@ public partial class Home : ComponentBase
     bool IsCanceled;
     Dictionary<int, string> Files = new();
 
-    protected override Task OnInitializedAsync()
+    protected override async Task OnInitializedAsync()
     {
-        matchingBankTransactions = viewService.MatchOpenBankTransactions();
+        matchingBankTransactions = await viewService.MatchOpenBankTransactionsAsync();
-        accounts = viewService.GetAccountViewList();
+        accounts = await viewService.GetAccountViewListAsync();
-        bookingTexts = bookingTextRepository.GetBookingTextList().Select(b => b.Text).ToArray();
+        bookingTexts = (await bookingTextRepository.GetBookingTextListAsync()).Select(b => b.Text).ToArray();
-        return base.OnInitializedAsync();
+        await base.OnInitializedAsync();
     }
     
     async Task OnProgressChangeAsync(FluentInputFileEventArgs file)
@@ -96,12 +96,12 @@ public partial class Home : ComponentBase
             File.Delete(file.Value);
         }
 
-        matchingBankTransactions = viewService.MatchOpenBankTransactions();
+        matchingBankTransactions = await viewService.MatchOpenBankTransactionsAsync();
     }
 
     private async Task ImportXmlAndShowResultAsync(string fileName)
     {
-        var messages = fileService.ImportAccountStatementFile(fileName);
+        var messages = await fileService.ImportAccountStatementFileAsync(fileName);
         foreach (var message in messages)
         {
             await ShowImportResultAsync(message);
@@ -156,9 +156,8 @@ public partial class Home : ComponentBase
             ShowToast("Transaktion kann wegen fehlenden Daten nicht gespeichert werden!", ToastIntent.Error);
             return;
         }
-        transactionRepository.SaveTransaction(transaction);
+        await transactionRepository.SaveTransactionAsync(transaction);
         transaction.ReadOnly = true;
-        await Task.CompletedTask;
     }
     
     private async Task SplitBankTransactionAsync(Transaction transaction)

Schaad.Accounting.UI/Components/Pages/Reports/BalanceReport.razor

@@ -1,5 +1,11 @@
 @page "/BalanceReport"
 
+@if (balance is null)
+{
+    <p>Lädt…</p>
+    return;
+}
+
 <h3>@header</h3>
 <a href="javascript:window.print()" class="hidePrint">Print</a>
 

Schaad.Accounting.UI/Components/Pages/Reports/BalanceReport.razor.cs

@@ -12,17 +12,17 @@ public partial class BalanceReport : ComponentBase
     [Inject]
     private ISettingsService settingsService { get; set; } = null!;
     
-    private BalanceDataset balance = null!;
+    private BalanceDataset? balance;
     private decimal win;
-    private string header = null!;
+    private string header = "";
-    private string footer = null!;
+    private string footer = "";
     
-    protected override Task OnInitializedAsync()
+    protected override async Task OnInitializedAsync()
     {
-        balance = viewService.GetBalanceView();
+        balance = await viewService.GetBalanceViewAsync();
         win = balance.TotalActivaCHF - balance.TotalPassivaCHF;
         (header, footer) = Report.GetViewDataTitleAndFooter("Bilanz", settingsService);
 
-        return base.OnInitializedAsync();  
+        await base.OnInitializedAsync();
     }
 }

Schaad.Accounting.UI/Components/Pages/Reports/BalanceSheetReport.razor

@@ -1,5 +1,11 @@
 @page "/BalanceSheetReport"
 
+@if (balanceSheet is null)
+{
+    <p>Lädt…</p>
+    return;
+}
+
 <h3>@header</h3>
 <a href="javascript:window.print()" class="hidePrint">Print</a>
 <br />

Schaad.Accounting.UI/Components/Pages/Reports/BalanceSheetReport.razor.cs

@@ -12,17 +12,17 @@ public partial class BalanceSheetReport : ComponentBase
     [Inject]
     private ISettingsService settingsService { get; set; } = null!;
     
-    private BalanceSheetDataset balanceSheet = null!;
+    private BalanceSheetDataset? balanceSheet;
     private decimal win;
-    private string header = null!;
+    private string header = "";
-    private string footer = null!;
+    private string footer = "";
     
-    protected override Task OnInitializedAsync()
+    protected override async Task OnInitializedAsync()
     {
-        balanceSheet = viewService.GetBalanceSheetView(settingsService.GetYear());
+        balanceSheet = await viewService.GetBalanceSheetViewAsync(settingsService.GetYear());
         win = balanceSheet.ProfitCHF - balanceSheet.LossCHF;
         (header, footer) = Report.GetViewDataTitleAndFooter("Jahresabschluss", settingsService);
 
-        return base.OnInitializedAsync();  
+        await base.OnInitializedAsync();
     }
 }

Schaad.Accounting.UI/Components/Pages/Reports/DetailReport.razor

@@ -1,5 +1,11 @@
 @page "/DetailReport"
 
+@if (accounts is null || transactions is null)
+{
+    <p>Lädt…</p>
+    return;
+}
+
 <h3>@header</h3>
 <a href="javascript:window.print()" class="hidePrint">Print</a>
 

Schaad.Accounting.UI/Components/Pages/Reports/DetailReport.razor.cs

@@ -12,23 +12,23 @@ public partial class DetailReport : ComponentBase
     [Inject]
     private ISettingsService settingsService { get; set; } = null!;
     
-    private IReadOnlyList<AccountDataset> accounts = null!;
+    private IReadOnlyList<AccountDataset>? accounts;
-    private IReadOnlyList<TransactionDataset> transactions = null!;
+    private IReadOnlyList<TransactionDataset>? transactions;
     private decimal profit;
     private decimal loss;
-    private string header = null!;
+    private string header = "";
-    private string footer = null!;
+    private string footer = "";
     
-    protected override Task OnInitializedAsync()
+    protected override async Task OnInitializedAsync()
     {
-        accounts = viewService.GetAccountViewList();
+        accounts = await viewService.GetAccountViewListAsync();
-        transactions = viewService.GetTransactionViewList();
+        transactions = await viewService.GetTransactionViewListAsync();
 
-        profit = Math.Abs(accounts.Where(m => m.Class == 3).Sum(m => m.Balance));
+        profit = Math.Abs(accounts.Where(m => m.Class == ClassIds.Income).Sum(m => m.Balance));
-        loss = Math.Abs(accounts.Where(m => m.Class == 4).Sum(m => m.Balance));
+        loss = Math.Abs(accounts.Where(m => m.Class == ClassIds.Expenses).Sum(m => m.Balance));
 
         (header, footer) = Report.GetViewDataTitleAndFooter("Detailaufstellung", settingsService);
 
-        return base.OnInitializedAsync();  
+        await base.OnInitializedAsync();
     }
 }

Schaad.Accounting.UI/Components/Pages/Reports/ProfitLossReport.razor

@@ -1,5 +1,11 @@
 @page "/ProfitLossReport"
 
+@if (accounts is null)
+{
+    <p>Lädt…</p>
+    return;
+}
+
 <h3>@header</h3>
 <a href="javascript:window.print()" class="hidePrint">Print</a>
 

Schaad.Accounting.UI/Components/Pages/Reports/ProfitLossReport.razor.cs

@@ -13,22 +13,22 @@ public partial class ProfitLossReport : ComponentBase
     [Inject]
     private ISettingsService settingsService { get; set; } = null!;
     
-    private IReadOnlyList<AccountDataset> accounts = null!;
+    private IReadOnlyList<AccountDataset>? accounts;
     private decimal profit;
     private decimal loss;
     private decimal win;
-    private string header = null!;
+    private string header = "";
-    private string footer = null!;
+    private string footer = "";
     
-    protected override Task OnInitializedAsync()
+    protected override async Task OnInitializedAsync()
     {
-        accounts = viewService.GetAccountViewList();
+        accounts = await viewService.GetAccountViewListAsync();
         profit = Math.Abs(accounts.Where(m => m.Class == ClassIds.Income).Sum(m => m.Balance));
         loss = Math.Abs(accounts.Where(m => m.Class == ClassIds.Expenses).Sum(m => m.Balance));
-        win = profit-loss;
+        win = profit - loss;
 
         (header, footer) = Report.GetViewDataTitleAndFooter("Erfolgsrechnung", settingsService);
 
-        return base.OnInitializedAsync();  
+        await base.OnInitializedAsync();
     }
 }

Schaad.Accounting.UI/Components/Pages/Transactions.razor

@@ -10,7 +10,7 @@
             <FluentNavGroup Title="@(gr.Key)" Expanded="true">
                 @foreach (var account in gr)
                 {
-                    <FluentNavLink OnClick="() => ShowTransactions(account.Id)" Icon="@(new Icons.Regular.Size24.CalendarAgenda())">
+                    <FluentNavLink OnClick="() => ShowTransactionsAsync(account.Id)" Icon="@(new Icons.Regular.Size24.CalendarAgenda())">
                         <FluentStack Orientation="Orientation.Horizontal">
                             <div>
                                 @account.Number / @account.Name
@@ -29,36 +29,39 @@
     </FluentNavMenu>
     
     <FluentBodyContent>
-        <FluentGrid Justify="JustifyContent.FlexStart">
+        @if (selectedAccount is not null)
-            <FluentGridItem xs="4" Class="align-content-center title">
+        {
-                @selectedAccount.Name
+            <FluentGrid Justify="JustifyContent.FlexStart">
-            </FluentGridItem>
+                <FluentGridItem xs="4" Class="align-content-center title">
-            <FluentGridItem xs="4" Class="align-content-center">
+                    @selectedAccount.Name
-                Total @Math.Abs(selectedAccount.Balance).ToString("N2") @selectedAccount.Currency in @transactionList?.Count() Transaktionen
+                </FluentGridItem>
-            </FluentGridItem>
+                <FluentGridItem xs="4" Class="align-content-center">
-            <FluentGridItem xs="4" Class="align-content-center" Justify="JustifyContent.FlexEnd">
+                    Total @Math.Abs(selectedAccount.Balance).ToString("N2") @selectedAccount.Currency in @transactionList?.Count() Transaktionen
-                <FluentButton IconStart="@(new Icons.Regular.Size16.Add())" Appearance="Appearance.Neutral" OnClick="AddAsync">Neue Transaktion hinzufügen</FluentButton>
+                </FluentGridItem>
-            </FluentGridItem>
+                <FluentGridItem xs="4" Class="align-content-center" Justify="JustifyContent.FlexEnd">
-        </FluentGrid>
+                    <FluentButton IconStart="@(new Icons.Regular.Size16.Add())" Appearance="Appearance.Neutral" OnClick="AddAsync">Neue Transaktion hinzufügen</FluentButton>
+                </FluentGridItem>
+            </FluentGrid>
 
-        <FluentPaginator State="@pagination" SummaryTemplate="@template"/>
+            <FluentPaginator State="@pagination" SummaryTemplate="@template"/>
-        <FluentDataGrid Items="@transactionList" Pagination="@pagination" RowSize="DataGridRowSize.Medium">
+            <FluentDataGrid Items="@transactionList" Pagination="@pagination" RowSize="DataGridRowSize.Medium">
-            <PropertyColumn Property="@(p => p.BookingDate)" Format="dd.MM.yyyy" Sortable="true" IsDefaultSortColumn="true" InitialSortDirection="SortDirection.Descending"/>
+                <PropertyColumn Property="@(p => p.BookingDate)" Format="dd.MM.yyyy" Sortable="true" IsDefaultSortColumn="true" InitialSortDirection="SortDirection.Descending"/>
-            <PropertyColumn Property="@(p => p.ValueDate)" Format="dd.MM.yyyy" Sortable="true"/>
+                <PropertyColumn Property="@(p => p.ValueDate)" Format="dd.MM.yyyy" Sortable="true"/>
-            <PropertyColumn Property="@(p => p.Text)"/>
+                <PropertyColumn Property="@(p => p.Text)"/>
-            <TemplateColumn Title="Gegenkonto">
+                <TemplateColumn Title="Gegenkonto">
-                @GetAccountName(context)
+                    @GetAccountName(context)
-            </TemplateColumn>
+                </TemplateColumn>
-            <TemplateColumn Title="Betrag" Align="Align.End">
+                <TemplateColumn Title="Betrag" Align="Align.End">
-                @context.GetValue(selectedAccount.IsFxAccount).ToString("N2") @selectedAccount.Currency
+                    @context.GetValue(selectedAccount.IsFxAccount).ToString("N2") @selectedAccount.Currency
-            </TemplateColumn>
+                </TemplateColumn>
-            <TemplateColumn Align="Align.Center" Width="50px">
+                <TemplateColumn Align="Align.Center" Width="50px">
-                <FluentButton IconEnd="@(new Icons.Regular.Size16.Delete())" Appearance="Appearance.Neutral" OnClick="@(() => DeleteAsync(context.Id))"/>
+                    <FluentButton IconEnd="@(new Icons.Regular.Size16.Delete())" Appearance="Appearance.Neutral" OnClick="@(() => DeleteAsync(context.Id))"/>
-            </TemplateColumn>
+                </TemplateColumn>
-            <TemplateColumn Align="Align.Center" Width="50px">
+                <TemplateColumn Align="Align.Center" Width="50px">
-                <FluentButton IconEnd="@(new Icons.Regular.Size16.Edit())" Appearance="Appearance.Neutral" OnClick="@(() => EditAsync(context.Id))"/>
+                    <FluentButton IconEnd="@(new Icons.Regular.Size16.Edit())" Appearance="Appearance.Neutral" OnClick="@(() => EditAsync(context.Id))"/>
-            </TemplateColumn>
+                </TemplateColumn>
-        </FluentDataGrid>
+            </FluentDataGrid>
+        }
     </FluentBodyContent>
 </FluentStack>
 

Schaad.Accounting.UI/Components/Pages/Transactions.razor.cs

@@ -1,4 +1,4 @@
-using Microsoft.AspNetCore.Components;
+using Microsoft.AspNetCore.Components;
 using Microsoft.FluentUI.AspNetCore.Components;
 using Schaad.Accounting.Datasets;
 using Schaad.Accounting.Interfaces;
@@ -18,24 +18,24 @@ public partial class Transactions : ComponentBase
     [Inject]
     private IDialogService dialogService { get; set; } = null!;
 
-    private IReadOnlyList<AccountDataset> accounts = null!;
+    private IReadOnlyList<AccountDataset> accounts = [];
 
     private IQueryable<TransactionDataset>? transactionList;
-    private string selectedAccountId = null!;
+    private string? selectedAccountId;
-    private AccountDataset selectedAccount = null!;
+    private AccountDataset? selectedAccount;
 
-    protected override Task OnInitializedAsync()  
+    protected override async Task OnInitializedAsync()
     {
-        accounts = viewService.GetAccountViewList();
+        accounts = await viewService.GetAccountViewListAsync();
-        ShowTransactions(accounts.First().Id);
+        await ShowTransactionsAsync(accounts.First().Id);
-        return base.OnInitializedAsync();
+        await base.OnInitializedAsync();
     }
 
-    private void ShowTransactions(string accountId)
+    private async Task ShowTransactionsAsync(string accountId)
     {
         selectedAccountId = accountId;
         selectedAccount = accounts.Single(a => a.Id == accountId);
-        transactionList = viewService.GetTransactionViewList(accountId).AsQueryable();
+        transactionList = (await viewService.GetTransactionViewListAsync(accountId)).AsQueryable();
     }
 
     private string GetAccountName(TransactionDataset transaction)
@@ -68,13 +68,13 @@ public partial class Transactions : ComponentBase
         var result = await dialog.Result;
         if (!result.Cancelled && result.Data != null)
         {
-            transactionList = viewService.GetTransactionViewList(selectedAccountId).AsQueryable();
+            transactionList = (await viewService.GetTransactionViewListAsync(selectedAccountId)).AsQueryable();
         }
     }
 
     private async Task EditAsync(string id)
     {
-        var data = transactionRepository.GetTransaction(id);
+        var data = await transactionRepository.GetTransactionAsync(id);
         var dialog = await dialogService.ShowDialogAsync<TransactionDialog>(data, new DialogParameters()
         {
             Height = "500px",
@@ -86,19 +86,19 @@ public partial class Transactions : ComponentBase
         var result = await dialog.Result;
         if (!result.Cancelled && result.Data != null)
         {
-            transactionList = viewService.GetTransactionViewList(selectedAccountId).AsQueryable();
+            transactionList = (await viewService.GetTransactionViewListAsync(selectedAccountId)).AsQueryable();
         }
     }
 
     private async Task DeleteAsync(string id)
     {
-        var transaction = transactionRepository.GetTransaction(id);
+        var transaction = await transactionRepository.GetTransactionAsync(id);
         var dialog = await dialogService.ShowConfirmationAsync($"Transaction '{transaction.Text}' mit Betrag {transaction.Value} wirklich löschen?", "Ja", "Nein", "Transaktion löschen");
         var result = await dialog.Result;
         if (!result.Cancelled)
         {
-            transactionRepository.DeleteTransaction(id);
+            await transactionRepository.DeleteTransactionAsync(id);
-            transactionList = viewService.GetTransactionViewList(selectedAccountId).AsQueryable();
+            transactionList = (await viewService.GetTransactionViewListAsync(selectedAccountId)).AsQueryable();
         }
     }
 }