Streamable HTTP - improve usability, fast mcp and auth (#641)

tests/server/test_streamable_http_manager.py

@@ -0,0 +1,81 @@
+"""Tests for StreamableHTTPSessionManager."""
+
+import anyio
+import pytest
+
+from mcp.server.lowlevel import Server
+from mcp.server.streamable_http_manager import StreamableHTTPSessionManager
+
+
+@pytest.mark.anyio
+async def test_run_can_only_be_called_once():
+    """Test that run() can only be called once per instance."""
+    app = Server("test-server")
+    manager = StreamableHTTPSessionManager(app=app)
+
+    # First call should succeed
+    async with manager.run():
+        pass
+
+    # Second call should raise RuntimeError
+    with pytest.raises(RuntimeError) as excinfo:
+        async with manager.run():
+            pass
+
+    assert (
+        "StreamableHTTPSessionManager .run() can only be called once per instance"
+        in str(excinfo.value)
+    )
+
+
+@pytest.mark.anyio
+async def test_run_prevents_concurrent_calls():
+    """Test that concurrent calls to run() are prevented."""
+    app = Server("test-server")
+    manager = StreamableHTTPSessionManager(app=app)
+
+    errors = []
+
+    async def try_run():
+        try:
+            async with manager.run():
+                # Simulate some work
+                await anyio.sleep(0.1)
+        except RuntimeError as e:
+            errors.append(e)
+
+    # Try to run concurrently
+    async with anyio.create_task_group() as tg:
+        tg.start_soon(try_run)
+        tg.start_soon(try_run)
+
+    # One should succeed, one should fail
+    assert len(errors) == 1
+    assert (
+        "StreamableHTTPSessionManager .run() can only be called once per instance"
+        in str(errors[0])
+    )
+
+
+@pytest.mark.anyio
+async def test_handle_request_without_run_raises_error():
+    """Test that handle_request raises error if run() hasn't been called."""
+    app = Server("test-server")
+    manager = StreamableHTTPSessionManager(app=app)
+
+    # Mock ASGI parameters
+    scope = {"type": "http", "method": "POST", "path": "/test"}
+
+    async def receive():
+        return {"type": "http.request", "body": b""}
+
+    async def send(message):
+        pass
+
+    # Should raise error because run() hasn't been called
+    with pytest.raises(RuntimeError) as excinfo:
+        await manager.handle_request(scope, receive, send)
+
+    assert "Task group is not initialized. Make sure to use run()." in str(
+        excinfo.value
+    )