Include actual media type in InvalidSchemaMediaTypeException

CHANGELOG.md

@@ -6,6 +6,8 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.1.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
 ## [Unreleased]
+### Fixed
+- UriRetriever: Include actual media type in InvalidSchemaMediaTypeException message ([#872](https://github.com/jsonrainbow/json-schema/pull/872))
 
 ## [6.6.4] - 2025-12-19
 ### Changed

src/JsonSchema/Uri/UriRetriever.php

@@ -91,7 +91,7 @@ public function confirmMediaType($uriRetriever, $uri)
             }
         }
 
-        throw new InvalidSchemaMediaTypeException(sprintf('Media type %s expected', Validator::SCHEMA_MEDIA_TYPE));
+        throw new InvalidSchemaMediaTypeException(sprintf('Media type %s expected, but %s given', Validator::SCHEMA_MEDIA_TYPE, $contentType));
     }
 
     /**

tests/Uri/UriRetrieverTest.php

@@ -263,6 +263,20 @@ public function testConfirmMediaTypeThrowsExceptionForUnsupportedTypes(): void
         $retriever->confirmMediaType($uriRetriever, null);
     }
 
+    public function testConfirmMediaTypeExceptionIncludesActualMediaType(): void
+    {
+        $uriRetriever = $this->createMock(\JsonSchema\Uri\Retrievers\UriRetrieverInterface::class);
+        $retriever = new UriRetriever();
+        $uriRetriever->expects($this->at(0))
+                ->method('getContentType')
+                ->willReturn('text/html');
+
+        $this->expectException(InvalidSchemaMediaTypeException::class);
+        $this->expectExceptionMessage('Media type application/schema+json expected, but text/html given');
+
+        $retriever->confirmMediaType($uriRetriever, null);
+    }
+
     private function mockRetriever($schema): void
     {
         $retrieverMock = $this->getRetrieverMock($schema);