Read group documentation from document tags.

src/Refitter.Core/IdentifierUtils.cs

@@ -53,4 +53,14 @@ public static string Sanitize(this string value)
         return string.Join(string.Empty, value.Split(IllegalSymbols, StringSplitOptions.RemoveEmptyEntries))
                 .Trim(dash);
     }
+
+    /// <summary>
+    /// Sanitizes and formats controller tags for identifier usage.
+    /// </summary>
+    /// <param name="tag">The tag to sanitize.</param>
+    /// <returns>A sanitized, title-cased identifier string.</returns>
+    public static string SanitizeControllerTag(this string tag)
+    {
+        return tag.Sanitize().CapitalizeFirstCharacter();
+    }
 }

src/Refitter.Core/RefitInterfaceGenerator.cs

@@ -363,7 +363,7 @@ private string GenerateInterfaceDeclaration(out string interfaceName)
 
         var modifier = settings.TypeAccessibility.ToString().ToLowerInvariant();
         var code = new StringBuilder();
-        docGenerator.AppendInterfaceDocumentation(document, code);
+        docGenerator.AppendSingleInterfaceDocumentation(document, code);
         code.Append($"""
                 {Separator}{GetGeneratedCodeAttribute()}
                 {Separator}{modifier} partial interface {interfaceName}{inheritance}

src/Refitter.Core/RefitMultipleInterfaceByTagGenerator.cs

@@ -49,7 +49,7 @@ public override IEnumerable<GeneratedCode> GenerateCode()
                 if (!interfacesByGroup.TryGetValue(kv.Key, out var sb))
                 {
                     interfacesByGroup[kv.Key] = sb = new StringBuilder();
-                    this.docGenerator.AppendInterfaceDocumentation(operation, sb);
+                    this.docGenerator.AppendInterfaceDocumentationByTag(document, kv.Key, sb);
 
                     interfaceName = GetInterfaceName(kv.Key);
                     sb.AppendLine($$"""
@@ -131,8 +131,7 @@ private string GetGroupName(OpenApiOperation operation, string ungroupedTitle)
     {
         if (operation.Tags.FirstOrDefault() is string group && !string.IsNullOrWhiteSpace(group))
         {
-            return IdentifierUtils.Sanitize(group)
-                .CapitalizeFirstCharacter();
+            return group.SanitizeControllerTag();
         }
 
         return ungroupedTitle;

src/Refitter.Core/RefitMultipleInterfaceGenerator.cs

@@ -36,7 +36,7 @@ public override IEnumerable<GeneratedCode> GenerateCode()
                     : "Execute";
                 var code = new StringBuilder();
 
-                this.docGenerator.AppendInterfaceDocumentation(operation, code);
+                this.docGenerator.AppendInterfaceDocumentationByEndpoint(operation, code);
 
                 var interfaceName = GetInterfaceName(kv, verb, operation);
                 code.AppendLine($$"""

src/Refitter.Core/XmlDocumentationGenerator.cs

@@ -19,6 +19,11 @@
     /// </summary>
     private const string Separator = "    ";
 
+    /// <summary>
+    /// The name of the XML documentation tag used for summaries.
+    /// </summary>
+    private const string SummaryTag = "summary";
+
     /// <summary>
     /// Instantiates a new instance of the <see cref="XmlDocumentationGenerator"/> class.
     /// </summary>
@@ -29,39 +34,62 @@
     }
 
     /// <summary>
-    /// Appends XML docs for the given interface definition to the given code builder.
-    /// This uses the OpenAPI operation info to generate the summary and remarks.
+    /// Generates an interface description from the tags of the given OpenAPI document and appends it to the builder.
+    /// </summary>
+    /// <param name="document">The parent document of the controller.</param>
+    /// <param name="tag">The controller tag that the endpoints were grouped by.</param>
+    /// <param name="code">The builder to append the documentation to.</param>
+    public void AppendInterfaceDocumentationByTag(OpenApiDocument document, string tag, StringBuilder code)
+    {
+        if (!_settings.GenerateXmlDocCodeComments)
+        {
+            return;
+        }
+
+        var controllerTag = document.Tags.FirstOrDefault(t => t.Name.SanitizeControllerTag() == tag);
+        var controllerDescription = controllerTag?.Description;
+        if (!string.IsNullOrEmpty(controllerDescription))
+        {
+            this.AppendXmlCommentBlock(SummaryTag, EscapeSymbols(controllerDescription), code, indent: Separator);
+        }
+    }
+
+    /// <summary>
+    /// Generates an interface description from the summary of the given endpoint and appends it to the builder.
     /// </summary>
-    /// <param name="group">The OpenAPI definition of the interface.</param>
+    /// <param name="endpoint">The OpenAPI definition of the endpoint.</param>
     /// <param name="code">The builder to append the documentation to.</param>
-    public void AppendInterfaceDocumentation(OpenApiOperation group, StringBuilder code)
+    public void AppendInterfaceDocumentationByEndpoint(OpenApiOperation endpoint, StringBuilder code)
     {
         if (!_settings.GenerateXmlDocCodeComments)
         {
             return;
         }
 
-        this.AppendXmlCommentBlock("summary", group?.Summary ?? "No summary available", code, indent: Separator);
+        var summary = endpoint.Summary;
+        if (!string.IsNullOrEmpty(summary))
+        {
+            this.AppendXmlCommentBlock(SummaryTag, EscapeSymbols(summary), code, indent: Separator);
+        }
     }
 
     /// <summary>
-    /// Appends XML docs for the given interface definition to the given code builder.
-    /// This uses the OpenAPI document's info description as the summary.
+    /// Generates an interface description from the title of the given document and appends it to the builder.
     /// </summary>
-    /// <param name="document">The OpenAPI definition of the interface.</param>
+    /// <param name="document">The OpenAPI definition of the document.</param>
     /// <param name="code">The builder to append the documentation to.</param>
-    public void AppendInterfaceDocumentation(OpenApiDocument document, StringBuilder code)
+    public void AppendSingleInterfaceDocumentation(OpenApiDocument document, StringBuilder code)
     {
         if (!_settings.GenerateXmlDocCodeComments)
         {
             return;
         }
 
-        this.AppendXmlCommentBlock(
-            "summary",
-            document.Info?.Title ?? "Refit interface - no description available",
-            code,
-            indent: Separator);
+        var title = document.Info?.Title;
+        if (!string.IsNullOrEmpty(title))
+        {
+            this.AppendXmlCommentBlock(SummaryTag, EscapeSymbols(title), code, indent: Separator);
+        }
     }
 
     /// <summary>
@@ -85,7 +113,7 @@
             return;
 
         if (!string.IsNullOrWhiteSpace(method.Summary))
-            this.AppendXmlCommentBlock("summary", EscapeSymbols(method.Summary), code);
+            this.AppendXmlCommentBlock(SummaryTag, EscapeSymbols(method.Summary), code);
 
         if (!string.IsNullOrWhiteSpace(method.Description))
             this.AppendXmlCommentBlock("remarks", EscapeSymbols(method.Description), code);

src/Refitter.SourceGenerator.Tests/AdditionalFiles/Generated/SwaggerPetstoreMultipleInterfaces.g.cs

@@ -191,7 +191,6 @@ public partial interface IUpdatePetWithFormEndpoint
     public partial interface IDeletePetEndpoint
     {
         /// <summary>Deletes a pet</summary>
-        /// <param name="api_key">api_key parameter</param>
         /// <param name="petId">Pet id to delete</param>
         /// <param name="cancellationToken">The cancellation token to cancel the request.</param>
         /// <returns>A <see cref="Task"/> that completes when the request is finished.</returns>
@@ -219,7 +218,6 @@ public partial interface IUploadFileEndpoint
         /// <summary>uploads an image</summary>
         /// <param name="petId">ID of pet to update</param>
         /// <param name="additionalMetadata">Additional Metadata</param>
-        /// <param name="body">body parameter</param>
         /// <param name="cancellationToken">The cancellation token to cancel the request.</param>
         /// <returns>
         /// A <see cref="Task"/> representing the <see cref="IApiResponse"/> instance containing the result:
@@ -258,7 +256,6 @@ public partial interface IPlaceOrderEndpoint
     {
         /// <summary>Place an order for a pet</summary>
         /// <remarks>Place a new order in the store</remarks>
-        /// <param name="body">body parameter</param>
         /// <param name="cancellationToken">The cancellation token to cancel the request.</param>
         /// <returns>successful operation</returns>
         /// <exception cref="ApiException">
@@ -360,7 +357,6 @@ public partial interface ICreateUsersWithListInputEndpoint
     {
         /// <summary>Creates list of users with given input array</summary>
         /// <remarks>Creates list of users with given input array</remarks>
-        /// <param name="body">body parameter</param>
         /// <param name="cancellationToken">The cancellation token to cancel the request.</param>
         /// <returns>Successful operation</returns>
         /// <exception cref="ApiException">Thrown when the request returns a non-success status code.</exception>

src/Refitter.SourceGenerator.Tests/AdditionalFiles/Generated/SwaggerPetstoreMultipleInterfacesByTag.g.cs

@@ -14,7 +14,7 @@
 
 namespace Refitter.Tests.AdditionalFiles.ByTag
 {
-    /// <summary>Update an existing pet</summary>
+    /// <summary>Everything about your Pets</summary>
     [System.CodeDom.Compiler.GeneratedCode("Refitter", "1.0.0.0")]
     public partial interface IPetApi
     {
@@ -195,7 +195,7 @@ public partial interface IPetApi
         Task<ApiResponse> UploadFile(long petId, [Query] string additionalMetadata, StreamPart body);
     }
 
-    /// <summary>Returns pet inventories by status</summary>
+    /// <summary>Operations about user</summary>
     [System.CodeDom.Compiler.GeneratedCode("Refitter", "1.0.0.0")]
     public partial interface IStoreApi
     {
@@ -276,7 +276,7 @@ public partial interface IStoreApi
         Task DeleteOrder(long orderId);
     }
 
-    /// <summary>Create user</summary>
+    /// <summary>Access to Petstore orders</summary>
     [System.CodeDom.Compiler.GeneratedCode("Refitter", "1.0.0.0")]
     public partial interface IUserApi
     {

src/Refitter.SourceGenerator.Tests/AdditionalFiles/Generated/UseJsonInheritanceConverter.g.cs

@@ -12,7 +12,6 @@
 
 namespace Refitter.Tests.UseJsonInheritanceConverter
 {
-    /// <summary>Refit interface - no description available</summary>
     [System.CodeDom.Compiler.GeneratedCode("Refitter", "1.0.0.0")]
     public partial interface IApiClient
     {

src/Refitter.SourceGenerator.Tests/AdditionalFiles/Generated/UsePolymorphicSerialization.g.cs

@@ -12,7 +12,6 @@
 
 namespace Refitter.Tests.UsePolymorphicSerialization
 {
-    /// <summary>Refit interface - no description available</summary>
     [System.CodeDom.Compiler.GeneratedCode("Refitter", "1.0.0.0")]
     public partial interface IApiClient
     {

src/Refitter.Tests/XmlDocumentationGeneratorTests.cs

@@ -22,7 +22,7 @@ public void Can_Generate_Interface_Doc_Without_Linebreaks()
     {
         var docs = new StringBuilder();
         var interfaceDefinition = new OpenApiOperation { Summary = "Test", };
-        this._generator.AppendInterfaceDocumentation(interfaceDefinition, docs);
+        this._generator.AppendInterfaceDocumentationByEndpoint(interfaceDefinition, docs);
         docs.ToString().Trim().Should().Be("/// <summary>Test</summary>");
     }
 
@@ -31,12 +31,24 @@ public void Can_Generate_Interface_Doc_With_Linebreaks()
     {
         var docs = new StringBuilder();
         var interfaceDefinition = new OpenApiOperation { Summary = "Test\n", };
-        this._generator.AppendInterfaceDocumentation(interfaceDefinition, docs);
+        this._generator.AppendInterfaceDocumentationByEndpoint(interfaceDefinition, docs);
         docs.ToString().Trim().Should().NotBe("/// <summary>Test</summary>");
         docs.ToString().Trim().Should().Contain("<summary>")
             .And.Contain("Test");
     }
 
+    [Test]
+    public void Can_Generate_Interface_Doc_From_Controller_Tag()
+    {
+        var docs = new StringBuilder();
+        var controllerTag =  new OpenApiTag { Name = "TestController", Description = "TestControllerDescription" };
+        var document =  new OpenApiDocument { Tags = [controllerTag] };
+
+        this._generator.AppendInterfaceDocumentationByTag(document, "TestController", docs);
+
+        docs.ToString().Trim().Should().Be("/// <summary>TestControllerDescription</summary>");
+    }
+
     [Test]
     public void Can_Generate_Method_Summary()
     {