Analyzer for informing MethodDataSource > InstanceMethodDataSource (#…

…2048) * Analyzer for informing MethodDataSource > InstanceMethodDataSource * Fix * Fix logic * Fix test
thomhurst · Mar 10, 2025 · b169852 · b169852
1 parent e0ff476
commit b169852
Show file tree

Hide file tree

Showing 6 changed files with 84 additions and 3 deletions.
diff --git a/TUnit.Analyzers.Tests/MethodDataSourceAnalyzerTests.cs b/TUnit.Analyzers.Tests/MethodDataSourceAnalyzerTests.cs
@@ -698,4 +698,33 @@ public static
                 """
             );
     }
+
+    [Test]
+    public async Task Method_Data_Source_Is_Flagged_When_Instance_Method_And_Wrong_Attribute()
+    {
+        await Verifier
+            .VerifyAnalyzerAsync(
+                """
+                using TUnit.Core;
+                using System;
+
+                [Arguments(1)]
+                public class MyClass(int _)
+                {
+                    [{|#0:MethodDataSource(nameof(One))|}]
+                    [Test]
+                    public void MyTest(int value)
+                    {
+                    }
+                    
+                    public int One()
+                    {
+                        return 1;
+                    }
+                }
+                """,
+                Verifier.Diagnostic(Rules.InstanceMethodSource)
+                    .WithLocation(0)
+            );
+    }
 }
diff --git a/TUnit.Analyzers/Resources.Designer.cs b/TUnit.Analyzers/Resources.Designer.cs
diff --git a/TUnit.Analyzers/Resources.resx b/TUnit.Analyzers/Resources.resx
@@ -513,4 +513,13 @@
     <data name="TUnit0055Title" xml:space="preserve">
         <value>Do not overwrite the Console writer</value>
     </data>
+    <data name="TUnit0056Description" xml:space="preserve">
+        <value>Instance methods used as data sources must use the `InstanceMethodDataSource` attribute.</value>
+    </data>
+    <data name="TUnit0056MessageFormat" xml:space="preserve">
+        <value>Instance methods used as data sources must use the `InstanceMethodDataSource` attribute</value>
+    </data>
+    <data name="TUnit0056Title" xml:space="preserve">
+        <value>Instance methods used as data sources must use the `InstanceMethodDataSource` attribute</value>
+    </data>
 </root>
diff --git a/TUnit.Analyzers/Rules.cs b/TUnit.Analyzers/Rules.cs
@@ -135,6 +135,9 @@ public static class Rules
     public static readonly DiagnosticDescriptor OverwriteConsole =
         CreateDescriptor("TUnit0055", UsageCategory, DiagnosticSeverity.Warning);
 
+    public static readonly DiagnosticDescriptor InstanceMethodSource =
+        CreateDescriptor("TUnit0056", UsageCategory, DiagnosticSeverity.Error);
+
     private static DiagnosticDescriptor CreateDescriptor(string diagnosticId, string category, DiagnosticSeverity severity)
     {
         return new DiagnosticDescriptor(

diff --git a/TUnit.Analyzers/TestDataAnalyzer.cs b/TUnit.Analyzers/TestDataAnalyzer.cs
@@ -25,7 +25,8 @@ public class TestDataAnalyzer : ConcurrentDiagnosticAnalyzer
             Rules.MustHavePropertySetter,
             Rules.ReturnFunc,
             Rules.MatrixDataSourceAttributeRequired,
-            Rules.TooManyArguments);
+            Rules.TooManyArguments,
+            Rules.InstanceMethodSource);
 
     protected override void InitializeInternal(AnalysisContext context)
     { 
@@ -322,6 +323,18 @@ private void CheckMethodDataSource(SymbolAnalysisContext context,
                 return;
             }
 
+            if (!dataSourceMethod.IsStatic 
+                && !dataSourceMethod.ContainingType.InstanceConstructors.Any(c => c.Parameters.IsDefaultOrEmpty)
+                && SymbolEqualityComparer.Default.Equals(dataSourceMethod.ContainingType, testClassType))
+            {
+                context.ReportDiagnostic(
+                    Diagnostic.Create(
+                        Rules.InstanceMethodSource,
+                        attribute.GetLocation())
+                );
+                return;
+            }
+
             var canBeInstanceMethod = context.Symbol is IPropertySymbol or IMethodSymbol
                 && testClassType.InstanceConstructors.First().Parameters.IsDefaultOrEmpty;
 

diff --git a/TUnit.TestProject/GenericTests.cs b/TUnit.TestProject/GenericTests.cs
@@ -19,8 +19,8 @@ public async Task Test()
     public abstract Task DataDrivenTest(T t);
 
     [Test]
-    [MethodDataSource(nameof(GetData))]
-    [MethodDataSource(nameof(GetEnumerableData))]
+    [InstanceMethodDataSource(nameof(GetData))]
+    [InstanceMethodDataSource(nameof(GetEnumerableData))]
     public async Task DataSourceDrivenTest(T t)
     {
         await Task.CompletedTask;