add unit test for Streamable HTTP Trailing Slash Compatibility

Author: chiliu

tests/server/test_fastmcp_streamable_http_mount.py

@@ -11,15 +11,15 @@ def fastmcp_app():
     return app
 
 def test_streamable_http_mount_dual_paths(fastmcp_app):
-    # Use httpx.ASGITransport to avoid DeprecationWarning
-    transport = httpx.ASGITransport(app=fastmcp_app)
-    client = httpx.Client(transport=transport, base_url="http://testserver")
-    for path in ["/mcp", "/mcp/"]:
-        # Should return 406 because Accept header is missing, but proves route exists
-        resp = client.post(
-            path, json={"jsonrpc": "2.0", "method": "initialize", "id": 1}
-        )
-        assert resp.status_code in (400, 406)  # 406 Not Acceptable or 400 Bad Request
-        # Optionally, test GET as well
-        resp_get = client.get(path)
-        assert resp_get.status_code in (400, 406, 405)
+    # Use httpx.AsyncClient with ASGITransport for async test
+    async def do_test():
+        async with httpx.AsyncClient(app=fastmcp_app, base_url="http://testserver") as client:
+            for path in ["/mcp", "/mcp/"]:
+                resp = await client.post(
+                    path, json={"jsonrpc": "2.0", "method": "initialize", "id": 1}
+                )
+                assert resp.status_code in (400, 406)
+                resp_get = await client.get(path)
+                assert resp_get.status_code in (400, 406, 405)
+    import anyio
+    anyio.run(do_test)