Suppress format warnings for response headers

Author: AayushP123

CHANGELOG.md

@@ -101,6 +101,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ### Changed
 
+- Fixed unsupported type-format warnings for response header schemas, which are always emitted as strings. [#4227](https://github.com/microsoft/kiota/issues/4227)
 - C#, Java, Go, PHP, Dart, TypeScript, Python and Ruby client: default value initialization in model classes for DateTime/Date/Time/UUID properties did not compile [#7404](https://github.com/microsoft/kiota/issues/7404)
 - All languages: default value initialization in model classes for numeric/boolean properties was missing [#7404](https://github.com/microsoft/kiota/issues/7404)
 - Fixed a bug where required query parameters from one HTTP operation were leaking into the path-item-level URL template, making them appear required for sibling operations on the same path. [#7292](https://github.com/microsoft/kiota/issues/7292)

src/Kiota.Builder/Validation/InconsistentTypeFormatPair.cs

@@ -48,7 +48,8 @@ public class InconsistentTypeFormatPair : ValidationRule<IOpenApiSchema>
     ];
     public InconsistentTypeFormatPair() : base(nameof(InconsistentTypeFormatPair), static (context, schema) =>
     {
-        if (schema is null || !schema.Type.HasValue || string.IsNullOrEmpty(schema.Format) || KnownAndNotSupportedFormats.knownAndUnsupportedFormats.Contains(schema.Format) || escapedTypes.Contains(schema.Type.Value))
+        if (KnownAndNotSupportedFormats.IsHeaderSchema(context.PathString) ||
+            schema is null || !schema.Type.HasValue || string.IsNullOrEmpty(schema.Format) || KnownAndNotSupportedFormats.knownAndUnsupportedFormats.Contains(schema.Format) || escapedTypes.Contains(schema.Type.Value))
             return;
         var sanitizedType = schema.Type.Value & ~JsonSchemaType.Null;
         if (!validPairs.TryGetValue(sanitizedType, out var validFormats) || !validFormats.Contains(schema.Format))

src/Kiota.Builder/Validation/KnownAndNotSupportedFormats.cs

@@ -25,9 +25,28 @@ public class KnownAndNotSupportedFormats : ValidationRule<IOpenApiSchema>
     };
     public KnownAndNotSupportedFormats() : base(nameof(KnownAndNotSupportedFormats), static (context, schema) =>
     {
-        if (!string.IsNullOrEmpty(schema.Format) && knownAndUnsupportedFormats.Contains(schema.Format))
+        if (!IsHeaderSchema(context.PathString) &&
+            !string.IsNullOrEmpty(schema.Format) && knownAndUnsupportedFormats.Contains(schema.Format))
             context.CreateWarning(nameof(KnownAndNotSupportedFormats), $"The format {schema.Format} is not supported by Kiota and the string type will be used.");
     })
     {
     }
+
+    internal static bool IsHeaderSchema(string? path)
+    {
+        if (string.IsNullOrEmpty(path))
+            return false;
+        var pathSegments = path.Split('/', StringSplitOptions.RemoveEmptyEntries);
+        for (var i = 0; i < pathSegments.Length - 1; i++)
+        {
+            if (pathSegments[i].Equals("components", StringComparison.OrdinalIgnoreCase) &&
+                pathSegments[i + 1].Equals("headers", StringComparison.OrdinalIgnoreCase))
+                return true;
+            if (pathSegments[i].Equals("responses", StringComparison.OrdinalIgnoreCase) &&
+                i + 2 < pathSegments.Length &&
+                pathSegments[i + 2].Equals("headers", StringComparison.OrdinalIgnoreCase))
+                return true;
+        }
+        return false;
+    }
 }

tests/Kiota.Builder.Tests/Validation/InconsistentTypeFormatPairTests.cs

@@ -98,6 +98,30 @@ public async Task DoesntAddWarningOnNullable()
                 type: string
                 format: binary
                 nullable: true
+""";
+        var diagnostic = await GetDiagnosticFromDocumentAsync(documentTxt);
+        Assert.Empty(diagnostic.Warnings);
+    }
+    [Fact]
+    public async Task DoesntAddAWarningForResponseHeaders()
+    {
+        var documentTxt =
+    """
+openapi: 3.0.1
+info:
+  title: Sample API
+  version: 1.0.0
+paths:
+  /items:
+    post:
+      responses:
+        '201':
+          description: Created
+          headers:
+            Location:
+              schema:
+                type: string
+                format: int32
 """;
         var diagnostic = await GetDiagnosticFromDocumentAsync(documentTxt);
         Assert.Empty(diagnostic.Warnings);

tests/Kiota.Builder.Tests/Validation/KnownAndNotSupportedFormatsTests.cs

@@ -75,6 +75,77 @@ public async Task DoesntFailWhenNoFormat()
         var diagnostic = await GetDiagnosticFromDocumentAsync(documentTxt);
         Assert.Empty(diagnostic.Warnings);
     }
+    [Fact]
+    public async Task DoesntAddAWarningForResponseHeaders()
+    {
+        var documentTxt =
+    """
+openapi: 3.0.1
+info:
+  title: Sample API
+  version: 1.0.0
+paths:
+  /items:
+    post:
+      responses:
+        '201':
+          description: Created
+          headers:
+            Location:
+              schema:
+                type: string
+                format: uri
+""";
+        var diagnostic = await GetDiagnosticFromDocumentAsync(documentTxt);
+        Assert.Empty(diagnostic.Warnings);
+    }
+    [Fact]
+    public async Task DoesntAddAWarningForComponentHeaders()
+    {
+        var documentTxt =
+    """
+openapi: 3.0.1
+info:
+  title: Sample API
+  version: 1.0.0
+paths: {}
+components:
+  headers:
+    Location:
+      schema:
+        type: string
+        format: uri
+""";
+        var diagnostic = await GetDiagnosticFromDocumentAsync(documentTxt);
+        Assert.Empty(diagnostic.Warnings);
+    }
+    [Fact]
+    public async Task AddsAWarningForSchemaPropertyNamedHeaders()
+    {
+        var documentTxt =
+    """
+openapi: 3.0.1
+info:
+  title: Sample API
+  version: 1.0.0
+paths:
+  /items:
+    get:
+      responses:
+        '200':
+          description: Success
+          content:
+            application/json:
+              schema:
+                type: object
+                properties:
+                  headers:
+                    type: string
+                    format: uri
+""";
+        var diagnostic = await GetDiagnosticFromDocumentAsync(documentTxt);
+        Assert.Single(diagnostic.Warnings);
+    }
     private static async Task<OpenApiDiagnostic> GetDiagnosticFromDocumentAsync(string document)
     {
         var rule = new KnownAndNotSupportedFormats();