fix(mcp): add missing __init__.py for chart, dashboard, dataset packages (#38400)

tests/unit_tests/mcp_service/test_mcp_tool_registration.py

@@ -37,3 +37,56 @@ def test_mcp_prompts_registered():
 
     prompts = mcp._prompt_manager._prompts
     assert len(prompts) > 0
+
+
+def test_mcp_resources_registered():
+    """Test that MCP resources are registered.
+
+    Resources are registered via @mcp.resource() decorators in resource files.
+    They require __init__.py in parent packages for find_packages() to include
+    them in distributions. This test ensures all expected resources are found.
+    """
+    from superset.mcp_service.app import mcp
+
+    resource_manager = mcp._resource_manager
+    resources = resource_manager._resources
+    assert len(resources) > 0, "No MCP resources registered"
+
+    # Verify the two documented resources are registered
+    resource_uris = set(resources.keys())
+    assert "chart://configs" in resource_uris, (
+        "chart://configs resource not registered - "
+        "check superset/mcp_service/chart/__init__.py exists"
+    )
+    assert "instance://metadata" in resource_uris, (
+        "instance://metadata resource not registered - "
+        "check superset/mcp_service/system/resources/ imports"
+    )
+
+
+def test_mcp_packages_discoverable_by_setuptools():
+    """Test that all MCP sub-packages have __init__.py for setuptools.
+
+    setuptools.find_packages() only discovers directories with __init__.py.
+    Without __init__.py, sub-packages (tool, resources, prompts) are excluded
+    from built distributions, causing missing module errors in deployments.
+    """
+    from pathlib import Path
+
+    mcp_root = Path(__file__).parents[3] / "superset" / "mcp_service"
+    assert mcp_root.is_dir(), f"MCP service root not found: {mcp_root}"
+
+    # All immediate sub-directories that contain Python files should be packages
+    missing = []
+    for subdir in sorted(mcp_root.iterdir()):
+        if not subdir.is_dir() or subdir.name.startswith(("_", ".")):
+            continue
+        # Check if it has any .py files in it or its subdirectories
+        has_py = any(subdir.rglob("*.py"))
+        if has_py and not (subdir / "__init__.py").exists():
+            missing.append(subdir.name)
+
+    assert not missing, (
+        f"MCP sub-packages missing __init__.py (will be excluded from "
+        f"setuptools distributions): {missing}"
+    )