chore: import upstream snapshot with attribution

tests/server/tasks/test_task_protocol.py

@@ -0,0 +1,81 @@
+"""
+Tests for SEP-1686 protocol-level task handling.
+
+Generic protocol tests that use tools as test fixtures.
+Tests metadata, notifications, and error handling at the protocol level.
+"""
+
+import pytest
+
+from fastmcp import FastMCP
+from fastmcp.client import Client
+
+
+@pytest.fixture
+async def task_enabled_server():
+    """Create a FastMCP server with task-enabled tools."""
+    mcp = FastMCP("task-test-server")
+
+    @mcp.tool(task=True)
+    async def simple_tool(message: str) -> str:
+        """A simple tool for testing."""
+        return f"Processed: {message}"
+
+    @mcp.tool(task=True)
+    async def failing_tool() -> str:
+        """A tool that always fails."""
+        raise ValueError("This tool always fails")
+
+    return mcp
+
+
+async def test_task_metadata_includes_task_id_and_ttl(task_enabled_server):
+    """Task metadata properly includes server-generated taskId and ttl."""
+    async with Client(task_enabled_server) as client:
+        # Submit with specific ttl (server generates task ID)
+        task = await client.call_tool(
+            "simple_tool",
+            {"message": "test"},
+            task=True,
+            ttl=30000,
+        )
+        assert task
+        assert not task.returned_immediately
+
+        # Server should have generated a task ID
+        assert task.task_id is not None
+        assert isinstance(task.task_id, str)
+
+
+async def test_task_notification_sent_after_submission(task_enabled_server):
+    """Server sends an initial task status notification after submission."""
+
+    @task_enabled_server.tool(task=True)
+    async def background_tool(message: str) -> str:
+        return f"Processed: {message}"
+
+    async with Client(task_enabled_server) as client:
+        task = await client.call_tool("background_tool", {"message": "test"}, task=True)
+        assert task
+        assert not task.returned_immediately
+
+        # Verify we can query the task
+        status = await task.status()
+        assert status.task_id == task.task_id
+
+
+async def test_failed_task_stores_error(task_enabled_server):
+    """Failed tasks store the error in results."""
+
+    @task_enabled_server.tool(task=True)
+    async def failing_task_tool() -> str:
+        raise ValueError("This tool always fails")
+
+    async with Client(task_enabled_server) as client:
+        task = await client.call_tool("failing_task_tool", task=True)
+        assert task
+        assert not task.returned_immediately
+
+        # Wait for task to fail
+        status = await task.wait(state="failed", timeout=2.0)
+        assert status.status == "failed"