Add diagnostic analyzer for service registration validation

Directory.Packages.props

@@ -12,9 +12,8 @@
     <PackageVersion Include="Microsoft.Extensions.DependencyInjection" Version="10.0.5" />
     <PackageVersion Include="Microsoft.NET.Test.Sdk" Version="18.3.0" />
     <PackageVersion Include="MinVer" Version="7.0.0" />
-    <PackageVersion Include="Verify.Xunit" Version="31.12.5" />
-    <PackageVersion Include="xunit" Version="2.9.3" />
+    <PackageVersion Include="Verify.XunitV3" Version="31.15.0" />
+    <PackageVersion Include="xunit.v3" Version="1.1.0" />
     <PackageVersion Include="XUnit.Hosting" Version="4.0.0" />
-    <PackageVersion Include="xunit.runner.visualstudio" Version="3.1.5" />
   </ItemGroup>
 </Project>

src/Injectio.Generators/AnalyzerReleases.Shipped.md

@@ -0,0 +1,2 @@
+; Shipped analyzer releases
+; https://github.com/dotnet/roslyn-analyzers/blob/main/src/Microsoft.CodeAnalysis.Analyzers/ReleaseTrackingAnalyzers.Help.md

src/Injectio.Generators/AnalyzerReleases.Unshipped.md

@@ -0,0 +1,16 @@
+; Unshipped analyzer release
+; https://github.com/dotnet/roslyn-analyzers/blob/main/src/Microsoft.CodeAnalysis.Analyzers/ReleaseTrackingAnalyzers.Help.md
+
+### New Rules
+
+Rule ID | Category | Severity | Notes
+--------|----------|----------|-------
+INJECT0001 | Injectio | Warning | RegisterServices method has invalid signature
+INJECT0002 | Injectio | Warning | RegisterServices method has invalid second parameter
+INJECT0003 | Injectio | Warning | RegisterServices method has too many parameters
+INJECT0004 | Injectio | Warning | Factory method not found
+INJECT0005 | Injectio | Warning | Factory method must be static
+INJECT0006 | Injectio | Warning | Factory method has invalid signature
+INJECT0007 | Injectio | Warning | Implementation does not implement service type
+INJECT0008 | Injectio | Warning | Implementation type is abstract
+INJECT0009 | Injectio | Warning | RegisterServices on non-static method in abstract class

src/Injectio.Generators/DiagnosticDescriptors.cs

@@ -0,0 +1,80 @@
+using Microsoft.CodeAnalysis;
+
+namespace Injectio.Generators;
+
+public static class DiagnosticDescriptors
+{
+    private const string Category = "Injectio";
+
+    public static readonly DiagnosticDescriptor InvalidMethodSignature = new(
+        id: "INJECT0001",
+        title: "RegisterServices method has invalid signature",
+        messageFormat: "Method '{0}' marked with [RegisterServices] must have IServiceCollection as its first parameter",
+        category: Category,
+        defaultSeverity: DiagnosticSeverity.Warning,
+        isEnabledByDefault: true);
+
+    public static readonly DiagnosticDescriptor InvalidMethodSecondParameter = new(
+        id: "INJECT0002",
+        title: "RegisterServices method has invalid second parameter",
+        messageFormat: "Method '{0}' marked with [RegisterServices] has an invalid second parameter; expected a string collection (e.g., IEnumerable<string>)",
+        category: Category,
+        defaultSeverity: DiagnosticSeverity.Warning,
+        isEnabledByDefault: true);
+
+    public static readonly DiagnosticDescriptor MethodTooManyParameters = new(
+        id: "INJECT0003",
+        title: "RegisterServices method has too many parameters",
+        messageFormat: "Method '{0}' marked with [RegisterServices] has {1} parameters; expected 1 or 2",
+        category: Category,
+        defaultSeverity: DiagnosticSeverity.Warning,
+        isEnabledByDefault: true);
+
+    public static readonly DiagnosticDescriptor FactoryMethodNotFound = new(
+        id: "INJECT0004",
+        title: "Factory method not found",
+        messageFormat: "Factory method '{0}' was not found on type '{1}'",
+        category: Category,
+        defaultSeverity: DiagnosticSeverity.Warning,
+        isEnabledByDefault: true);
+
+    public static readonly DiagnosticDescriptor FactoryMethodNotStatic = new(
+        id: "INJECT0005",
+        title: "Factory method must be static",
+        messageFormat: "Factory method '{0}' on type '{1}' must be static",
+        category: Category,
+        defaultSeverity: DiagnosticSeverity.Warning,
+        isEnabledByDefault: true);
+
+    public static readonly DiagnosticDescriptor FactoryMethodInvalidSignature = new(
+        id: "INJECT0006",
+        title: "Factory method has invalid signature",
+        messageFormat: "Factory method '{0}' on type '{1}' must accept IServiceProvider as its first parameter and optionally object? as its second parameter",
+        category: Category,
+        defaultSeverity: DiagnosticSeverity.Warning,
+        isEnabledByDefault: true);
+
+    public static readonly DiagnosticDescriptor ServiceTypeMismatch = new(
+        id: "INJECT0007",
+        title: "Implementation does not implement service type",
+        messageFormat: "Type '{0}' does not implement or inherit from service type '{1}'",
+        category: Category,
+        defaultSeverity: DiagnosticSeverity.Warning,
+        isEnabledByDefault: true);
+
+    public static readonly DiagnosticDescriptor AbstractImplementationType = new(
+        id: "INJECT0008",
+        title: "Implementation type is abstract",
+        messageFormat: "Implementation type '{0}' is abstract and cannot be instantiated without a factory method",
+        category: Category,
+        defaultSeverity: DiagnosticSeverity.Warning,
+        isEnabledByDefault: true);
+
+    public static readonly DiagnosticDescriptor RegisterServicesMethodOnAbstractClass = new(
+        id: "INJECT0009",
+        title: "RegisterServices on non-static method in abstract class",
+        messageFormat: "Method '{0}' marked with [RegisterServices] is a non-static method on abstract class '{1}'; the class cannot be instantiated",
+        category: Category,
+        defaultSeverity: DiagnosticSeverity.Warning,
+        isEnabledByDefault: true);
+}

src/Injectio.Generators/Injectio.Generators.csproj

@@ -27,4 +27,9 @@
     </None>
   </ItemGroup>
 
+  <ItemGroup>
+    <AdditionalFiles Include="AnalyzerReleases.Shipped.md" />
+    <AdditionalFiles Include="AnalyzerReleases.Unshipped.md" />
+  </ItemGroup>
+
 </Project>