Add common.compat alias for BaseEventTrigger

providers/apache/iceberg/pyproject.toml

@@ -60,7 +60,7 @@ requires-python = ">=3.10"
 # After you modify the dependencies, and rebuild your Breeze CI image with ``breeze ci-image build``
 dependencies = [
     "apache-airflow>=2.11.0",
-    "apache-airflow-providers-common-compat>=1.8.0",
+    "apache-airflow-providers-common-compat>=1.8.0",  # use next version
     "pyiceberg>=0.8.0",
 ]
 

providers/apache/iceberg/src/airflow/providers/apache/iceberg/triggers/iceberg.py

@@ -22,15 +22,8 @@
 from pyiceberg.exceptions import NoSuchNamespaceError, NoSuchTableError
 
 from airflow.providers.apache.iceberg.hooks.iceberg import IcebergHook
-from airflow.providers.apache.iceberg.version_compat import AIRFLOW_V_3_0_PLUS
-
-if AIRFLOW_V_3_0_PLUS:
-    from airflow.triggers.base import BaseEventTrigger, TriggerEvent
-else:
-    from airflow.triggers.base import (  # type: ignore[assignment]
-        BaseTrigger as BaseEventTrigger,
-        TriggerEvent,
-    )
+from airflow.providers.common.compat.triggers import BaseEventTrigger
+from airflow.triggers.base import TriggerEvent
 
 if TYPE_CHECKING:
     from collections.abc import AsyncIterator

providers/common/compat/src/airflow/providers/common/compat/triggers.py

@@ -0,0 +1,38 @@
+# 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.
+"""Compatibility imports for core trigger base classes across Airflow 2 and Airflow 3."""
+
+from __future__ import annotations
+
+from typing import TYPE_CHECKING
+
+from airflow.providers.common.compat._compat_utils import create_module_getattr
+
+if TYPE_CHECKING:
+    from airflow.triggers.base import BaseEventTrigger as BaseEventTrigger
+
+
+# Airflow 3.0 added BaseEventTrigger to mark triggers usable as event-driven scheduling sources.
+# Airflow 2.x has no such marker, so it falls back to BaseTrigger: subclasses still work as
+# deferred triggers there, they just cannot drive an asset watcher.
+_RENAME_MAP: dict[str, tuple[str, str, str]] = {
+    "BaseEventTrigger": ("airflow.triggers.base", "airflow.triggers.base", "BaseTrigger"),
+}
+
+__getattr__ = create_module_getattr(import_map={}, rename_map=_RENAME_MAP)
+
+__all__ = sorted(_RENAME_MAP.keys())

providers/common/compat/tests/unit/common/compat/test_triggers.py

@@ -0,0 +1,36 @@
+# 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
+
+import pytest
+
+import airflow.triggers.base
+from airflow.providers.common.compat import triggers
+
+
+class TestBaseEventTrigger:
+    def test_falls_back_to_base_trigger_without_base_event_trigger(self, monkeypatch):
+        """On Airflow 2.x, where the class does not exist, the alias resolves to BaseTrigger."""
+        # Already absent when the tests run against Airflow 2.x, which is the case being simulated.
+        monkeypatch.delattr(airflow.triggers.base, "BaseEventTrigger", raising=False)
+
+        assert triggers.BaseEventTrigger is airflow.triggers.base.BaseTrigger
+
+    def test_unknown_attribute_raises(self):
+        with pytest.raises(AttributeError, match="module has no attribute 'NotATrigger'"):
+            triggers.NotATrigger