Add json file support, (+ .yml extension) (#19)

* Implementation

* Update src/OpenApiSourceGenerator/OpenApiSourceGenerator.cs

Remove explicit call to AddJsonReader as this is natively supported

Co-authored-by: Copilot <[email protected]>

---------

Co-authored-by: Copilot <[email protected]>

Author: YVbakker

src/OpenApiSourceGenerator.Tests/Features/FileFormats.feature

@@ -0,0 +1,12 @@
+Feature: File Format Support
+Verify that different file extensions (.yaml, .yml, .json) are correctly recognized and parsed
+
+  Scenario Outline: Parse OpenAPI file with <extension> extension
+    When the code generator is executed with file extension <extension>
+    Then code should be generated
+
+    Examples:
+      | extension |
+      | .yaml     |
+      | .yml      |
+      | .json     |

src/OpenApiSourceGenerator.Tests/Features/Steps/FileFormatsStepDefinitions.cs

@@ -0,0 +1,83 @@
+using System.Linq;
+using Microsoft.CodeAnalysis;
+using Microsoft.CodeAnalysis.CSharp;
+using Microsoft.CodeAnalysis.Text;
+using OpenApiSourceGenerator;
+using Reqnroll;
+using Shouldly;
+
+namespace OpenApiSourceGenerator.Tests.Features.Steps;
+
+[Binding]
+public sealed class FileFormatsStepDefinitions(ScenarioContext scenarioContext)
+{
+    private const string MinimalYamlSpec = """
+        openapi: 3.0.0
+        info:
+          title: API
+          version: 1.0.0
+        paths: {}
+        components:
+          schemas:
+            Model:
+              type: object
+              properties:
+                Name:
+                  type: string
+        """;
+
+    private const string MinimalJsonSpec = """
+        {
+          "openapi": "3.0.0",
+          "info": {"title": "API", "version": "1.0.0"},
+          "paths": {},
+          "components": {
+            "schemas": {
+              "Model": {
+                "type": "object",
+                "properties": {
+                  "Name": {"type": "string"}
+                }
+              }
+            }
+          }
+        }
+        """;
+
+    [When("the code generator is executed with file extension {word}")]
+    public void WhenTheCodeGeneratorIsExecutedWithFileExtension(string extension)
+    {
+        var specification = extension == ".json" ? MinimalJsonSpec : MinimalYamlSpec;
+
+        var generator = new OpenApiSourceGenerator();
+
+        GeneratorDriver driver = CSharpGeneratorDriver.Create(generator);
+
+        // Add the OpenAPI specification as an additional file with the correct extension
+        driver = driver.AddAdditionalTexts(
+            [new TestAdditionalFile($"test{extension}", specification)]
+        );
+
+        // To run generators, we can use an empty compilation
+        var compilation = CSharpCompilation.Create(nameof(FileFormatsStepDefinitions));
+
+        driver.RunGeneratorsAndUpdateCompilation(compilation, out var newCompilation, out var diagnostics);
+
+        scenarioContext["GeneratedCompilation"] = newCompilation;
+        scenarioContext["Diagnostics"] = diagnostics;
+    }
+
+    [Then("code should be generated")]
+    public void ThenCodeShouldBeGenerated()
+    {
+        var newCompilation = (Compilation)scenarioContext["GeneratedCompilation"];
+        
+        // Get all generated syntax trees (excluding the empty compilation)
+        var generatedTrees = newCompilation.SyntaxTrees
+            .Where(t => !string.IsNullOrEmpty(t.FilePath))
+            .ToList();
+
+        // Verify that code was generated
+        generatedTrees.ShouldNotBeEmpty("No code was generated");
+    }
+}

src/OpenApiSourceGenerator.Tests/Features/Steps/OpenApiStepDefinitions.cs

@@ -101,22 +101,3 @@ public void ThenTheFollowingCodeShouldBeGenerated(string className, string expec
         generatedRoot.IsEquivalentTo(expectedRoot).ShouldBeTrue();
     }
 }
-
-// Helper class to create additional files for testing
-internal class TestAdditionalFile : AdditionalText
-{
-    private readonly string _text;
-
-    public TestAdditionalFile(string path, string text)
-    {
-        Path = path;
-        _text = text;
-    }
-
-    public override string Path { get; }
-
-    public override SourceText GetText(System.Threading.CancellationToken cancellationToken = default)
-    {
-        return SourceText.From(_text);
-    }
-}

src/OpenApiSourceGenerator.Tests/Features/Steps/TestAdditionalFile.cs

@@ -0,0 +1,20 @@
+using System.Threading;
+using Microsoft.CodeAnalysis;
+using Microsoft.CodeAnalysis.Text;
+
+namespace OpenApiSourceGenerator.Tests.Features.Steps;
+
+/// <summary>
+/// Helper class to create additional files for testing source generators
+/// </summary>
+internal class TestAdditionalFile(string path, string text) : AdditionalText
+{
+    private readonly string _text = text;
+
+    public override string Path { get; } = path;
+
+    public override SourceText GetText(CancellationToken cancellationToken = default)
+    {
+        return SourceText.From(_text);
+    }
+}

src/OpenApiSourceGenerator.Tests/OpenApiSourceGenerator.Tests.csproj

@@ -9,8 +9,8 @@
     <PackageReference Include="Microsoft.CodeAnalysis.Common" Version="5.0.0" />
     <PackageReference Include="Microsoft.CodeAnalysis.CSharp" Version="5.0.0" />
     <PackageReference Include="Microsoft.NET.Test.Sdk" Version="18.0.1" />
-    <PackageReference Include="Microsoft.OpenApi" Version="3.0.1" />
-    <PackageReference Include="Microsoft.OpenApi.YamlReader" Version="3.0.1" />
+    <PackageReference Include="Microsoft.OpenApi" Version="3.0.2" />
+    <PackageReference Include="Microsoft.OpenApi.YamlReader" Version="3.0.2" />
     <PackageReference Include="Reqnroll.TUnit" Version="3.2.1" />
     <PackageReference Include="Shouldly" Version="4.3.0" />
     <PackageReference Include="TUnit" Version="1.5.60" />

src/OpenApiSourceGenerator/OpenApiSourceGenerator.cs

@@ -40,17 +40,26 @@ public void Initialize(IncrementalGeneratorInitializationContext context)
         _openApiReaderSettings.AddYamlReader();
 
         var provider = context.AdditionalTextsProvider
-            .Where(file => file.Path.EndsWith(".yaml", StringComparison.OrdinalIgnoreCase))
+            .Where(file => file.Path.EndsWith(".yaml", StringComparison.OrdinalIgnoreCase) ||
+                           file.Path.EndsWith(".yml", StringComparison.OrdinalIgnoreCase) ||
+                           file.Path.EndsWith(".json", StringComparison.OrdinalIgnoreCase))
             .Collect();
 
         context.RegisterSourceOutput(provider, GenerateCode);
     }
 
     private void GenerateCode(SourceProductionContext context, ImmutableArray<AdditionalText> files)
     {
-        foreach (var text in files.Select(file => file.GetText()).Where(text => text is not null))
+        foreach (var file in files)
         {
-            var (openApiDocument, _) = OpenApiDocument.Parse(text!.ToString(), "yaml", _openApiReaderSettings);
+            var text = file.GetText();
+            if (text is null)
+            {
+                continue;
+            }
+
+            var format = file.Path.EndsWith(".json", StringComparison.OrdinalIgnoreCase) ? "json" : "yaml";
+            var (openApiDocument, _) = OpenApiDocument.Parse(text.ToString(), format, _openApiReaderSettings);
 
             if (openApiDocument is null)
             {

src/OpenApiSourceGenerator/OpenApiSourceGenerator.csproj

@@ -49,8 +49,6 @@
         </PackageReference>
         <PackageReference Include="Microsoft.CodeAnalysis.CSharp" Version="5.0.0"
             PrivateAssets="all" />
-        <PackageReference Include="Microsoft.CodeAnalysis.CSharp.Workspaces" Version="5.0.0"
-            PrivateAssets="all" />
         <PackageReference Include="Microsoft.OpenApi" Version="3.0.2" PrivateAssets="all"
             GeneratePathProperty="true" />
         <PackageReference Include="Microsoft.OpenApi.YamlReader" Version="3.0.2" PrivateAssets="all" GeneratePathProperty="true" />