Merge pull request #176 from sheffler/fixFirstProgressReport

progress_token is 0 on first tool-call and the return is taken mistakenly

tests/issues/test_176_progress_token.py

@@ -0,0 +1,46 @@
+from unittest.mock import AsyncMock, MagicMock
+
+import pytest
+
+from mcp.server.fastmcp import Context
+from mcp.shared.context import RequestContext
+
+pytestmark = pytest.mark.anyio
+
+
+async def test_progress_token_zero_first_call():
+    """Test that progress notifications work when progress_token is 0 on first call."""
+
+    # Create mock session with progress notification tracking
+    mock_session = AsyncMock()
+    mock_session.send_progress_notification = AsyncMock()
+
+    # Create request context with progress token 0
+    mock_meta = MagicMock()
+    mock_meta.progressToken = 0  # This is the key test case - token is 0
+
+    request_context = RequestContext(
+        request_id="test-request", session=mock_session, meta=mock_meta
+    )
+
+    # Create context with our mocks
+    ctx = Context(request_context=request_context, fastmcp=MagicMock())
+
+    # Test progress reporting
+    await ctx.report_progress(0, 10)  # First call with 0
+    await ctx.report_progress(5, 10)  # Middle progress
+    await ctx.report_progress(10, 10)  # Complete
+
+    # Verify progress notifications
+    assert (
+        mock_session.send_progress_notification.call_count == 3
+    ), "All progress notifications should be sent"
+    mock_session.send_progress_notification.assert_any_call(
+        progress_token=0, progress=0.0, total=10.0
+    )
+    mock_session.send_progress_notification.assert_any_call(
+        progress_token=0, progress=5.0, total=10.0
+    )
+    mock_session.send_progress_notification.assert_any_call(
+        progress_token=0, progress=10.0, total=10.0
+    )