push

Author: Kludex

src/mcp/server/mcpserver/resources/resource_manager.py

@@ -82,10 +82,8 @@ def add_template(
         return template
 
     async def get_resource(
-        self,
-        uri: AnyUrl | str,
-        context: Context[ServerSessionT, LifespanContextT, RequestT] | None = None,
-    ) -> Resource | None:
+        self, uri: AnyUrl | str, context: Context[ServerSessionT, LifespanContextT, RequestT] | None = None
+    ) -> Resource:
         """Get resource by URI, checking concrete resources first, then templates."""
         uri_str = str(uri)
         logger.debug("Getting resource", extra={"uri": uri_str})

src/mcp/server/mcpserver/server.py

@@ -347,8 +347,9 @@ async def read_resource(self, uri: AnyUrl | str) -> Iterable[ReadResourceContent
         """Read a resource by URI."""
 
         context = self.get_context()
-        resource = await self._resource_manager.get_resource(uri, context=context)
-        if not resource:
+        try:
+            resource = await self._resource_manager.get_resource(uri, context=context)
+        except ValueError:
             raise ResourceError(f"Unknown resource: {uri}")
 
         try:

tests/issues/test_141_resource_templates.py

@@ -2,6 +2,7 @@
 
 from mcp import Client
 from mcp.server.mcpserver import MCPServer
+from mcp.server.mcpserver.exceptions import ResourceError
 from mcp.types import (
     ListResourceTemplatesResult,
     TextResourceContents,
@@ -54,10 +55,10 @@ def get_user_profile_missing(user_id: str) -> str:  # pragma: no cover
     assert result_list[0].mime_type == "text/plain"
 
     # Verify invalid parameters raise error
-    with pytest.raises(ValueError, match="Unknown resource"):
+    with pytest.raises(ResourceError, match="Unknown resource"):
         await mcp.read_resource("resource://users/123/posts")  # Missing post_id
 
-    with pytest.raises(ValueError, match="Unknown resource"):
+    with pytest.raises(ResourceError, match="Unknown resource"):
         await mcp.read_resource("resource://users/123/posts/456/extra")  # Extra path component
 
 

tests/server/mcpserver/test_server.py

@@ -929,7 +929,7 @@ async def test_resource_decorator_with_metadata(self):
         mcp = MCPServer()
 
         @mcp.resource("resource://config", meta={"ui": {"component": "file-viewer"}, "priority": "high"})
-        def get_config() -> str: ...
+        def get_config() -> str: ...  # pragma: no branch
 
         resources = await mcp.list_resources()
         assert resources == snapshot(
@@ -950,7 +950,7 @@ async def test_resource_template_decorator_with_metadata(self):
         mcp = MCPServer()
 
         @mcp.resource("resource://{city}/weather", meta={"api_version": "v2", "deprecated": False})
-        def get_weather(city: str) -> str: ...
+        def get_weather(city: str) -> str: ...  # pragma: no branch
 
         templates = await mcp.list_resource_templates()
         assert templates == snapshot(
@@ -1277,15 +1277,14 @@ def test_prompt_decorator_error(self):
         with pytest.raises(TypeError, match="decorator was used incorrectly"):
 
             @mcp.prompt  # type: ignore
-            def fn() -> str:
-                return "Hello, world!"
+            def fn() -> str: ...  # pragma: no branch
 
     async def test_list_prompts(self):
         """Test listing prompts through MCP protocol."""
         mcp = MCPServer()
 
         @mcp.prompt()
-        def fn(name: str, optional: str = "default") -> str: ...
+        def fn(name: str, optional: str = "default") -> str: ...  # pragma: no branch
 
         async with Client(mcp) as client:
             result = await client.list_prompts()
@@ -1395,7 +1394,7 @@ async def test_get_prompt_missing_args(self):
         mcp = MCPServer()
 
         @mcp.prompt()
-        def prompt_fn(name: str) -> str: ...
+        def prompt_fn(name: str) -> str: ...  # pragma: no branch
 
         async with Client(mcp) as client:
             with pytest.raises(MCPError, match="Missing required arguments"):