feat: add @semantic_layer decorator for extension discovery

tests/unit_tests/semantic_layers/decorators_test.py

@@ -0,0 +1,109 @@
+# Licensed to the Apache Software Foundation (ASF) under one
+# or more contributor license agreements.  See the NOTICE file
+# distributed with this work for additional information
+# regarding copyright ownership.  The ASF licenses this file
+# to you under the Apache License, Version 2.0 (the
+# "License"); you may not use this file except in compliance
+# with the License.  You may obtain a copy of the License at
+#
+#   http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing,
+# software distributed under the License is distributed on an
+# "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+# KIND, either express or implied.  See the License for the
+# specific language governing permissions and limitations
+# under the License.
+
+from __future__ import annotations
+
+from unittest.mock import MagicMock, patch
+
+import pytest
+
+
+def test_semantic_layer_stub_raises() -> None:
+    """The stub decorator raises NotImplementedError before initialization."""
+    import importlib
+
+    import superset_core.semantic_layers.decorators as mod
+
+    # Reload to get the original stub (injection may have replaced it)
+    importlib.reload(mod)
+
+    with pytest.raises(NotImplementedError):
+        mod.semantic_layer(id="test", name="Test")
+
+
+def test_inject_semantic_layer_host_context() -> None:
+    """The injected decorator registers a class in host context."""
+    from superset.semantic_layers.registry import registry
+
+    # Clear registry for test isolation
+    registry.clear()
+
+    with patch(
+        "superset.core.api.core_api_injection.get_current_extension_context",
+        return_value=None,
+    ):
+        from superset.core.api.core_api_injection import (
+            inject_semantic_layer_implementations,
+        )
+
+        inject_semantic_layer_implementations()
+
+    import superset_core.semantic_layers.decorators as mod
+
+    @mod.semantic_layer(id="test_layer", name="Test Layer", description="A test")
+    class FakeLayer:
+        pass
+
+    assert "test_layer" in registry
+    assert registry["test_layer"] is FakeLayer
+    assert FakeLayer.name == "Test Layer"  # type: ignore[attr-defined]
+    assert FakeLayer.description == "A test"  # type: ignore[attr-defined]
+
+    # Cleanup
+    registry.pop("test_layer", None)
+
+
+def test_inject_semantic_layer_extension_context() -> None:
+    """The injected decorator prefixes ID in extension context."""
+    from superset.semantic_layers.registry import registry
+
+    registry.clear()
+
+    mock_context = MagicMock()
+    mock_context.manifest.publisher = "acme"
+    mock_context.manifest.name = "analytics"
+
+    with patch(
+        "superset.core.api.core_api_injection.get_current_extension_context",
+        return_value=None,
+    ):
+        from superset.core.api.core_api_injection import (
+            inject_semantic_layer_implementations,
+        )
+
+        inject_semantic_layer_implementations()
+
+    import superset_core.semantic_layers.decorators as mod
+
+    # Now simulate extension context for the decorator call
+    with patch(
+        "superset.core.api.core_api_injection.get_current_extension_context",
+        return_value=mock_context,
+    ):
+        # Re-inject so the closure captures the mock context
+        inject_semantic_layer_implementations()
+
+    @mod.semantic_layer(id="ext_layer", name="Extension Layer")
+    class ExtLayer:
+        pass
+
+    expected_id = "extensions.acme.analytics.ext_layer"
+    assert expected_id in registry
+    assert registry[expected_id] is ExtLayer
+
+    # Cleanup
+    registry.pop(expected_id, None)