MA0052 is only reported for know formats

meziantou · Mar 25, 2023 · 5e05913 · 5e05913
1 parent 72a513b
commit 5e05913
Show file tree

Hide file tree

Showing 2 changed files with 120 additions and 0 deletions.
diff --git a/src/Meziantou.Analyzer/Rules/ReplaceEnumToStringWithNameofAnalyzer.cs b/src/Meziantou.Analyzer/Rules/ReplaceEnumToStringWithNameofAnalyzer.cs
@@ -47,6 +47,31 @@ private static void Analyze(OperationAnalysisContext context)
         if (expression.Member.ContainingType.EnumUnderlyingType == null)
             return;
 
+        if (operation.Arguments.Length > 0)
+        {
+            var format = operation.Arguments[0].Value;
+            if (format is { ConstantValue: { HasValue: true, Value: var formatValue } })
+            {
+                if (!IsNameFormat(formatValue))
+                    return;
+            }
+            else
+            {
+                return;
+            }
+        }
+
         context.ReportDiagnostic(s_rule, operation);
+
+        static bool IsNameFormat(object? format)
+        {
+            if (format is null)
+                return true;
+
+            if (format is string str && str is "g" or "G" or "f" or "F" or "")
+                return true;
+
+            return false;
+        }
     }
 }
diff --git a/tests/Meziantou.Analyzer.Test/Rules/ReplaceEnumToStringWithNameofAnalyzerTests.cs b/tests/Meziantou.Analyzer.Test/Rules/ReplaceEnumToStringWithNameofAnalyzerTests.cs
@@ -72,4 +72,99 @@ await CreateProjectBuilder()
               .WithSourceCode(SourceCode)
               .ValidateAsync();
     }
+
+    [Theory]
+    [InlineData("null")]
+    [InlineData("\"\"")]
+    [InlineData("\"G\"")]
+    [InlineData("\"g\"")]
+    [InlineData("\"F\"")]
+    [InlineData("\"f\"")]
+    public async Task ToString_Formats(string format)
+    {
+        var sourceCode = $$"""
+class Test
+{
+    void A()
+    {
+        _ = [|MyEnum.A.ToString(format: {{format}})|];
+    }
+}
+
+enum MyEnum
+{
+    A,
+}
+""";
+
+        var fix = """
+class Test
+{
+    void A()
+    {
+        _ = nameof(MyEnum.A);
+    }
+}
+
+enum MyEnum
+{
+    A,
+}
+""";
+
+        await CreateProjectBuilder()
+              .WithSourceCode(sourceCode)
+              .ShouldFixCodeWith(fix)
+              .ValidateAsync();
+    }
+
+    [Theory]
+    [InlineData("\"x\"")]
+    [InlineData("\"X\"")]
+    [InlineData("\"d\"")]
+    [InlineData("\"D\"")]
+    public async Task ToString_IncompatibleFormats(string format)
+    {
+        var sourceCode = $$"""
+class Test
+{
+    void A()
+    {
+        _ = MyEnum.A.ToString(format: {{format}});
+    }
+}
+
+enum MyEnum
+{
+    A,
+}
+""";
+
+        await CreateProjectBuilder()
+              .WithSourceCode(sourceCode)
+              .ValidateAsync();
+    }
+
+    [Fact]
+    public async Task ToString_DynamicFormat()
+    {
+        var sourceCode = $$"""
+class Test
+{
+    void A(string format)
+    {        
+        _ = MyEnum.A.ToString(format);
+    }
+}
+
+enum MyEnum
+{
+    A,
+}
+""";
+
+        await CreateProjectBuilder()
+              .WithSourceCode(sourceCode)
+              .ValidateAsync();
+    }
 }