xUnit TheoryData Migration Code Fix (#2464)

* Theory Data test

* xUnit TheoryData Migration Code Fix

Author: thomhurst

TUnit.Analyzers.CodeFixers/XUnitMigrationCodeFixProvider.cs

@@ -70,10 +70,66 @@ private static async Task<Document> ConvertCodeAsync(Document document, Cancella
         updatedRoot = RemoveUsingDirectives(updatedRoot);
         UpdateSyntaxTrees(ref compilation, ref syntaxTree, updatedRoot);
 
+        updatedRoot = ConvertTheoryData(compilation, updatedRoot);
+        UpdateSyntaxTrees(ref compilation, ref syntaxTree, updatedRoot);
+        
         // Apply all changes in one step
         return document.WithSyntaxRoot(updatedRoot);
     }
 
+    private static SyntaxNode ConvertTheoryData(Compilation compilation, SyntaxNode root)
+    {
+        var currentRoot = root;
+        foreach (var objectCreationExpressionSyntax in currentRoot.DescendantNodes().OfType<BaseObjectCreationExpressionSyntax>())
+        {
+            var type = objectCreationExpressionSyntax switch
+            {
+                ObjectCreationExpressionSyntax explicitObjectCreationExpressionSyntax => explicitObjectCreationExpressionSyntax.Type,
+                ImplicitObjectCreationExpressionSyntax implicitObjectCreationExpressionSyntax => SyntaxFactory.ParseTypeName(compilation.GetSemanticModel(implicitObjectCreationExpressionSyntax.SyntaxTree).GetTypeInfo(implicitObjectCreationExpressionSyntax).Type!.ToDisplayString()),
+                _ => null
+            };
+            
+            if (type is not GenericNameSyntax genericNameSyntax ||
+                genericNameSyntax.Identifier.Text != "TheoryData")
+            {
+                continue;
+            }
+            
+            var collectionItems = objectCreationExpressionSyntax.Initializer!
+                .ChildNodes()
+                .Select(x => x.DescendantNodesAndSelf().OfType<ExpressionSyntax>().First());
+
+            var arrayCreationExpressionSyntax = SyntaxFactory.ArrayCreationExpression(
+                SyntaxFactory.ArrayType(genericNameSyntax.TypeArgumentList.Arguments[0],
+                    SyntaxFactory.SingletonList(
+                        SyntaxFactory.ArrayRankSpecifier(
+                            SyntaxFactory.SingletonSeparatedList<ExpressionSyntax>(
+                                SyntaxFactory.OmittedArraySizeExpression()
+                            )
+                        )
+                    )
+                ),
+                SyntaxFactory.InitializerExpression(
+                    SyntaxKind.ArrayInitializerExpression,
+                    SyntaxFactory.SeparatedList(collectionItems)
+                )
+            ).NormalizeWhitespace();
+
+            currentRoot = currentRoot.ReplaceNode(objectCreationExpressionSyntax, arrayCreationExpressionSyntax);
+        }
+
+        foreach (var genericTheoryDataTypeSyntax in currentRoot.DescendantNodes().OfType<GenericNameSyntax>().Where(x => x.Identifier.Text == "TheoryData"))
+        {
+            var enumerableTypeSyntax = SyntaxFactory.GenericName(
+                SyntaxFactory.Identifier("IEnumerable"),
+                SyntaxFactory.TypeArgumentList(SyntaxFactory.SeparatedList(genericTheoryDataTypeSyntax.TypeArgumentList.Arguments)));
+
+            currentRoot = currentRoot.ReplaceNode(genericTheoryDataTypeSyntax, enumerableTypeSyntax);
+        }
+        
+        return currentRoot.NormalizeWhitespace();
+    }
+
     private static SyntaxNode UpdateInitializeDispose(Compilation compilation, SyntaxNode root)
     {
         // Always operate on the latest root

TUnit.Analyzers.Tests/XUnitMigrationAnalyzerTests.cs

@@ -501,4 +501,63 @@ public ValueTask DisposeAsync()
                 """
             );
     }
+    
+    [Test]
+    public async Task TheoryData_Is_Flagged()
+    {
+        await CodeFixer
+            .VerifyAnalyzerAsync(
+                """
+                {|#0:using System;
+                using Xunit;
+
+                public class MyClass
+                {
+                    public static readonly TheoryData<TimeSpan> Times = new()
+                    {
+                        TimeSpan.FromSeconds(1),
+                        TimeSpan.FromHours(1),
+                        TimeSpan.FromMilliseconds(10)
+                    };
+                }|}
+                """,
+                Verifier.Diagnostic(Rules.XunitMigration).WithLocation(0)
+            );
+    }
+    
+    [Test]
+    public async Task TheoryData_Can_Be_Converted()
+    {
+        await CodeFixer
+            .VerifyCodeFixAsync(
+                """
+                {|#0:using TUnit.Core;
+                using Xunit;
+
+                public class MyClass
+                {
+                    public static readonly TheoryData<TimeSpan> Times = new()
+                    {
+                        TimeSpan.FromSeconds(1),
+                        TimeSpan.FromHours(1),
+                        TimeSpan.FromMilliseconds(10)
+                    };
+                }|}
+                """,
+                Verifier.Diagnostic(Rules.XunitMigration).WithLocation(0),
+                """
+                using TUnit.Core;
+
+                public class MyClass
+                {
+                    public static readonly IEnumerable<TimeSpan> Times = new TimeSpan[]
+                    {
+                        TimeSpan.FromSeconds(1),
+                        TimeSpan.FromHours(1),
+                        TimeSpan.FromMilliseconds(10)
+                    };
+                }
+                """
+            );
+    }
 }