fix: #129 resource template handling in FastMCP server

tests/issues/test_129_resource_templates.py

@@ -0,0 +1,44 @@
+import pytest
+
+from mcp import types
+from mcp.server.fastmcp import FastMCP
+
+
+@pytest.mark.anyio
+async def test_resource_templates():
+    # Create an MCP server
+    mcp = FastMCP("Demo")
+
+    # Add a dynamic greeting resource
+    @mcp.resource("greeting://{name}")
+    def get_greeting(name: str) -> str:
+        """Get a personalized greeting"""
+        return f"Hello, {name}!"
+
+    @mcp.resource("users://{user_id}/profile")
+    def get_user_profile(user_id: str) -> str:
+        """Dynamic user data"""
+        return f"Profile data for user {user_id}"
+
+    # Get the list of resource templates using the underlying server
+    # Note: list_resource_templates() returns a decorator that wraps the handler
+    # The handler returns a ServerResult with a ListResourceTemplatesResult inside
+    result = await mcp._mcp_server.request_handlers[types.ListResourceTemplatesRequest](
+        types.ListResourceTemplatesRequest(
+            method="resources/templates/list", params=None, cursor=None
+        )
+    )
+    assert isinstance(result.root, types.ListResourceTemplatesResult)
+    templates = result.root.resourceTemplates
+
+    # Verify we get both templates back
+    assert len(templates) == 2
+
+    # Verify template details
+    greeting_template = next(t for t in templates if t.name == "get_greeting")
+    assert greeting_template.uriTemplate == "greeting://{name}"
+    assert greeting_template.description == "Get a personalized greeting"
+
+    profile_template = next(t for t in templates if t.name == "get_user_profile")
+    assert profile_template.uriTemplate == "users://{user_id}/profile"
+    assert profile_template.description == "Dynamic user data"