Fix style verification failures and add CI checks

.github/workflows/code-style.yml

@@ -0,0 +1,37 @@
+name: Code style
+
+on:
+  workflow_call:
+  workflow_dispatch:
+
+jobs:
+  verify:
+    name: Verify code style
+    runs-on: ubuntu-latest
+    timeout-minutes: 15
+    permissions:
+      contents: read
+    env:
+      DOTNET_CLI_UI_LANGUAGE: en-US
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v7
+      - name: Setup .NET
+        uses: actions/setup-dotnet@v6
+        with:
+          dotnet-version: |
+            8.0.x
+            9.0.x
+            10.0.x
+      - name: Restore solution
+        run: dotnet restore Eventuous.slnx
+      - name: Verify code style
+        shell: bash
+        run: |
+          set -euo pipefail
+          log_file="$RUNNER_TEMP/dotnet-format.log"
+          dotnet format style Eventuous.slnx --verify-no-changes --no-restore --severity warn --verbosity diagnostic 2>&1 | tee "$log_file"
+          if grep -Fq 'Required references did not load for ' "$log_file"; then
+            echo "::error::Code style verification was incomplete because project references could not be loaded."
+            exit 1
+          fi

.github/workflows/preview.yml

@@ -9,6 +9,10 @@ on:
       - '*.md'
 
 jobs:
+  code-style:
+    name: Code style
+    uses: ./.github/workflows/code-style.yml
+
   event_file:
     # Consumed by the Test Results workflow (test-results.yml) to publish results on the commit.
     name: "Event File"
@@ -28,7 +32,7 @@ jobs:
 
   nuget:
     runs-on: ubuntu-latest
-    needs: tests
+    needs: [ tests, code-style ]
     permissions:
       id-token: write
       contents: read

.github/workflows/pull-request.yml

@@ -11,6 +11,10 @@ concurrency:
   cancel-in-progress: true
 
 jobs:
+  code-style:
+    name: Code style
+    uses: ./.github/workflows/code-style.yml
+
   event_file:
     # Consumed by the Test Results workflow (test-results.yml) to publish results with the
     # correct PR context.

CONTRIBUTING.md

@@ -9,4 +9,22 @@ Here are simple rules that we expect to be followed by contributors:
 - Use the code formats of the repository, we have them in the `.editorconfig` file. Reformat the code accordingly if you copy it from somewhere.
 - Only contribute with your own work, or if you have a permission from the others to contribute their code.
 
+## Code style checks
+
+The reusable [code-style workflow](.github/workflows/code-style.yml) runs for pull requests and pushes to `dev`.
+
+Run the same style verification locally from the repository root:
+
+```sh
+dotnet format style Eventuous.slnx --verify-no-changes --severity warn
+```
+
+This checks Roslyn code-style rules at warning or error severity, including naming conventions and unnecessary imports. Apply available fixes with:
+
+```sh
+dotnet format style Eventuous.slnx --severity warn
+```
+
+Some violations, such as naming-rule violations, require manual fixes. Rerun verification after making changes. CI also fails if the formatter reports that required project references could not be loaded.
+
 Thanks for contributing!

src/Core/src/Eventuous.Diagnostics/EventuousDiagnostics.cs

@@ -9,13 +9,13 @@ public static class EventuousDiagnostics {
     static EventuousDiagnostics() {
         Enabled        = Environment.GetEnvironmentVariable("EVENTUOUS_DISABLE_DIAGS") != "1";
         ActivitySource = new(InstrumentationName, InstrumentationVersion.Value);
-        listener       = DummyActivityListener.Create();
-        ActivitySource.AddActivityListener(listener);
+        Listener       = DummyActivityListener.Create();
+        ActivitySource.AddActivityListener(Listener);
     }
 
     public const string InstrumentationName = DiagnosticName.BaseName;
 
-    static readonly ActivityListener listener;
+    static readonly ActivityListener Listener;
 
     public static KeyValuePair<string, object?>[] Tags { get; private set; } = [];
 
@@ -46,7 +46,7 @@ public static void AddDefaultTag(string key, object? value) {
 
     public static ActivitySource ActivitySource { get; }
 
-    public static void RemoveDummyListener() => listener.Dispose();
+    public static void RemoveDummyListener() => Listener.Dispose();
 
     public static Meter GetMeter(string name) => new(name, InstrumentationVersion.Value);
 

src/Core/src/Eventuous.Persistence/ExpectedStreamVersion.cs

@@ -11,10 +11,10 @@ public readonly record struct ExpectedStreamVersion(long Value) {
 }
 
 public record struct StreamReadPosition {
-    public StreamReadPosition(long Value) {
-        if (Value < 0) throw new ArgumentOutOfRangeException(nameof(Value), "StreamReadPosition cannot be negative.");
+    public StreamReadPosition(long value) {
+        if (value < 0) throw new ArgumentOutOfRangeException(nameof(value), "StreamReadPosition cannot be negative.");
 
-        this.Value = Value;
+        Value = value;
     }
 
     public static readonly StreamReadPosition Start = new(0L);

src/Core/src/Eventuous.Serialization/EventSerializer.cs

@@ -10,12 +10,12 @@ namespace Eventuous;
 /// </summary>
 [PublicAPI]
 public static class EventSerializer {
-    static IEventSerializer? _default;
+    static IEventSerializer? defaultSerializer;
 
     /// <summary>
     /// Gets the default event serializer. Throws if not configured.
     /// </summary>
-    public static IEventSerializer Default => _default
+    public static IEventSerializer Default => defaultSerializer
         ?? throw new InvalidOperationException(
             "No default event serializer configured. "
           + "Call EventSerializer.SetDefault() at startup or register IEventSerializer in DI. "
@@ -25,7 +25,7 @@ public static class EventSerializer {
     /// Sets the default event serializer instance.
     /// </summary>
     public static void SetDefault(IEventSerializer serializer)
-        => _default = serializer ?? throw new ArgumentNullException(nameof(serializer));
+        => defaultSerializer = serializer ?? throw new ArgumentNullException(nameof(serializer));
 
     /// <summary>
     /// Sets the default event serializer only if one has not already been configured.
@@ -34,6 +34,6 @@ public static void SetDefault(IEventSerializer serializer)
     public static bool TrySetDefault(IEventSerializer serializer) {
         ArgumentNullException.ThrowIfNull(serializer);
 
-        return Interlocked.CompareExchange(ref _default, serializer, null) == null;
+        return Interlocked.CompareExchange(ref defaultSerializer, serializer, null) == null;
     }
 }

src/Core/src/Eventuous.Shared/TypeMap/TypeMap.cs

@@ -46,23 +46,22 @@ struct MapEntry {
         public TV?  Value    { get; set; }
     }
 
-    // ReSharper disable once InconsistentNaming
     // ReSharper disable once StaticMemberInGenericType
-    static volatile int _index = -1;
+    static volatile int index = -1;
 
     const int DefaultCapacity = 10;
 
     // ReSharper disable once UnusedTypeParameter
     static class TypeSlot<T> {
         // ReSharper disable once StaticMemberInGenericType
-        internal static readonly int Index = Interlocked.Increment(ref _index);
+        internal static readonly int Index = Interlocked.Increment(ref index);
     }
 
     static int GetIndex<TK>() => TypeSlot<TK>.Index;
 
     static int RecommendedCapacity {
         get {
-            var capacity = _index + 1;
+            var capacity = index + 1;
 
             if (capacity < DefaultCapacity) {
                 capacity = DefaultCapacity;

src/Core/test/Eventuous.Tests.Shared.Analyzers/Analyzer_Ev001_Tests.cs

@@ -112,7 +112,7 @@ public async Task Should_stay_silent_when_event_type_attribute_cannot_be_resolve
         var compilation = CreateCompilation(source, includeSharedAssembly: false);
         var analyzer    = new EventUsageAnalyzer();
 
-        var diagnostics = await GetAnalyzerDiagnosticsAsync(compilation, analyzer);
+        var diagnostics = await GetAnalyzerDiagnosticsAsync(compilation, analyzer, allowCompilationErrors: true);
 
         await Assert.That(diagnostics.Length).IsEqualTo(0);
     }
@@ -128,11 +128,18 @@ public async Task Should_resolve_all_well_known_type_names() {
         await Assert.That(unresolved).IsEmpty();
     }
 
-    static async Task<Diagnostic[]> GetAnalyzerDiagnosticsAsync(Compilation compilation, EventUsageAnalyzer analyzer) {
+    static async Task<Diagnostic[]> GetAnalyzerDiagnosticsAsync(Compilation compilation, EventUsageAnalyzer analyzer, bool allowCompilationErrors = false) {
+        if (!allowCompilationErrors) {
+            var errors = compilation.GetDiagnostics().Where(d => d.Severity == DiagnosticSeverity.Error).ToArray();
+            await Assert.That(errors).IsEmpty();
+        }
+
         var withAnalyzers = compilation.WithAnalyzers([analyzer]);
         var diagnostics   = await withAnalyzers.GetAnalyzerDiagnosticsAsync().ConfigureAwait(false);
-        // Filter out anything not from our analyzer id just in case
-        return [.. diagnostics.Where(d => d.Id == EventUsageAnalyzer.DiagnosticId)];
+
+        // Fail on unexpected diagnostics, including analyzer failures such as AD0001.
+        await Assert.That(diagnostics.Where(d => d.Id != EventUsageAnalyzer.DiagnosticId)).IsEmpty();
+        return [.. diagnostics];
     }
 
     static string LoadAnalyzedSource([CallerFilePath] string? caller = null) {
@@ -148,7 +155,8 @@ static CSharpCompilation CreateCompilation(string source, bool includeSharedAsse
             MetadataReference.CreateFromFile(typeof(object).GetTypeInfo().Assembly.Location),
             MetadataReference.CreateFromFile(typeof(Enumerable).GetTypeInfo().Assembly.Location),
             MetadataReference.CreateFromFile(typeof(State<>).Assembly.Location),
-            MetadataReference.CreateFromFile(typeof(Aggregate<>).Assembly.Location)
+            MetadataReference.CreateFromFile(typeof(Aggregate<>).Assembly.Location),
+            MetadataReference.CreateFromFile(typeof(JetBrains.Annotations.UsedImplicitlyAttribute).Assembly.Location)
         };
 
         if (includeSharedAssembly) {
@@ -162,7 +170,7 @@ static CSharpCompilation CreateCompilation(string source, bool includeSharedAsse
         var runtimeDir = Path.GetDirectoryName(typeof(object).Assembly.Location)!;
         refs.AddRange(Directory.GetFiles(runtimeDir, "System.*.dll").Select(dll => MetadataReference.CreateFromFile(dll)).Cast<MetadataReference>());
 
-        TryAddRef(refs, "netstandard");
+        refs.Add(MetadataReference.CreateFromFile(Path.Combine(runtimeDir, "netstandard.dll")));
 
         var compilation = CSharpCompilation.Create(
             assemblyName: "Analyzer_Ev001_Tests_Assembly",
@@ -176,14 +184,4 @@ static CSharpCompilation CreateCompilation(string source, bool includeSharedAsse
 
         return compilation;
     }
-
-    static void TryAddRef(List<MetadataReference> refs, string asmName) {
-        try {
-            var asm = AppDomain.CurrentDomain.GetAssemblies().FirstOrDefault(a => a.GetName().Name == asmName);
-            if (asm != null) refs.Add(MetadataReference.CreateFromFile(asm.Location));
-        }
-        catch {
-            // ignore
-        }
-    }
 }

src/Core/test/Eventuous.Tests.Shared.Analyzers/Eventuous.Tests.Shared.Analyzers.csproj

@@ -4,6 +4,11 @@
         <OutputType>Exe</OutputType>
         <IsTestProject>true</IsTestProject>
     </PropertyGroup>
+    <ItemGroup>
+        <!-- Analyzer input is compiled and validated by the tests. -->
+        <Compile Remove="Analyzed.cs" />
+        <None Include="Analyzed.cs" />
+    </ItemGroup>
     <ItemGroup>
         <PackageReference Include="JetBrains.Annotations"/>
         <PackageReference Include="NodaTime.Serialization.SystemTextJson"/>

src/Mongo/test/Eventuous.Tests.Projections.MongoDB/Fixtures/IntegrationFixture.cs

@@ -42,7 +42,9 @@ public async Task InitializeAsync() {
         var settings = KurrentDBClientSettings.Create(_esdbContainer.GetConnectionString());
         Client          = new(settings);
         EventStore      = new KurrentDBEventStore(Client);
-        _mongoContainer = new MongoDbBuilder().WithImage("mongo:8").Build();
+        // MongoDB 8 cannot start on affected Linux 6.19+ kernels used by CI runners.
+        // MongoDB 7.0 is unaffected: https://jira.mongodb.org/browse/SERVER-125742
+        _mongoContainer = new MongoDbBuilder().WithImage("mongo:7.0").Build();
         await _mongoContainer.StartAsync();
         var mongoSettings = MongoClientSettings.FromConnectionString(_mongoContainer.GetConnectionString());
         Mongo = new MongoClient(mongoSettings).GetDatabase("bookings");

src/Postgres/test/Eventuous.Tests.Postgres/Subscriptions/GapAgeReleaseWhileRunningTest.cs

@@ -2,7 +2,6 @@
 // Licensed under the Apache License, Version 2.0.
 
 using Eventuous.Postgresql.Subscriptions;
-using Eventuous.Tests.Persistence.Base.Fixtures;
 using Eventuous.Tests.Subscriptions.Base;
 
 namespace Eventuous.Tests.Postgres.Subscriptions;

src/Postgres/test/Eventuous.Tests.Postgres/Subscriptions/GapRemediationBeforeSkipTest.cs

@@ -2,7 +2,6 @@
 // Licensed under the Apache License, Version 2.0.
 
 using Eventuous.Postgresql.Subscriptions;
-using Eventuous.Tests.Persistence.Base.Fixtures;
 using Eventuous.Tests.Subscriptions.Base;
 
 namespace Eventuous.Tests.Postgres.Subscriptions;

src/Postgres/test/Eventuous.Tests.Postgres/Subscriptions/GapSkipTimeoutTest.cs

@@ -2,7 +2,6 @@
 // Licensed under the Apache License, Version 2.0.
 
 using Eventuous.Postgresql.Subscriptions;
-using Eventuous.Tests.Persistence.Base.Fixtures;
 using Eventuous.Tests.Subscriptions.Base;
 
 namespace Eventuous.Tests.Postgres.Subscriptions;

src/Sqlite/test/Eventuous.Tests.Sqlite/Metrics/MetricsFixture.cs

@@ -6,7 +6,6 @@
 using Eventuous.Sqlite.Subscriptions;
 using Eventuous.Subscriptions.Checkpoints;
 using Eventuous.Subscriptions.Registrations;
-using Eventuous.TestHelpers.TUnit.Logging;
 using Eventuous.Tests.OpenTelemetry.Fakes;
 using Eventuous.Tests.OpenTelemetry.Fixtures;
 using Eventuous.Tests.Sqlite.Fixtures;