1 files changed, 108 insertions, 0 deletions
diff --git a/src/ansiblelint/rules/no_handler.py b/src/ansiblelint/rules/no_handler.py
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+++ b/src/ansiblelint/rules/no_handler.py
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+# Copyright (c) 2016 Will Thames <will@thames.id.au>
+#
+# Permission is hereby granted, free of charge, to any person obtaining a copy
+# of this software and associated documentation files (the "Software"), to deal
+# in the Software without restriction, including without limitation the rights
+# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+# copies of the Software, and to permit persons to whom the Software is
+# furnished to do so, subject to the following conditions:
+#
+# The above copyright notice and this permission notice shall be included in
+# all copies or substantial portions of the Software.
+#
+# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+# THE SOFTWARE.
+
+"""UseHandlerRatherThanWhenChangedRule used with ansible-lint."""
+from __future__ import annotations
+
+import sys
+from typing import TYPE_CHECKING
+
+from ansiblelint.rules import AnsibleLintRule
+
+if TYPE_CHECKING:
+    from ansiblelint.file_utils import Lintable
+    from ansiblelint.utils import Task
+
+
+def _changed_in_when(item: str) -> bool:
+    if not isinstance(item, str):
+        return False
+    item_list = item.split()
+
+    if {"and", "or", "not"} & set(item_list):
+        return False
+    return any(
+        changed in item
+        for changed in [
+            ".changed",
+            "|changed",
+            '["changed"]',
+            "['changed']",
+            "is changed",
+        ]
+    )
+
+
+class UseHandlerRatherThanWhenChangedRule(AnsibleLintRule):
+    """Tasks that run when changed should likely be handlers."""
+
+    id = "no-handler"
+    description = (
+        "If a task has a ``when: result.changed`` setting, it is effectively "
+        "acting as a handler. You could use ``notify`` and move that task to "
+        "``handlers``."
+    )
+    link = "https://docs.ansible.com/ansible/latest/playbook_guide/playbooks_handlers.html#handlers"
+    severity = "MEDIUM"
+    tags = ["idiom"]
+    version_added = "historic"
+
+    def matchtask(
+        self,
+        task: Task,
+        file: Lintable | None = None,
+    ) -> bool | str:
+        if task["__ansible_action_type__"] != "task":
+            return False
+
+        when = task.get("when")
+
+        if isinstance(when, list):
+            if len(when) > 1:
+                return False
+            return _changed_in_when(when[0])
+        if isinstance(when, str):
+            return _changed_in_when(when)
+        return False
+
+
+if "pytest" in sys.modules:
+    import pytest
+
+    from ansiblelint.rules import RulesCollection  # pylint: disable=ungrouped-imports
+    from ansiblelint.runner import Runner  # pylint: disable=ungrouped-imports
+
+    @pytest.mark.parametrize(
+        ("test_file", "failures"),
+        (
+            pytest.param("examples/playbooks/no_handler_fail.yml", 5, id="fail"),
+            pytest.param("examples/playbooks/no_handler_pass.yml", 0, id="pass"),
+        ),
+    )
+    def test_no_handler(
+        default_rules_collection: RulesCollection,
+        test_file: str,
+        failures: int,
+    ) -> None:
+        """Test rule matches."""
+        results = Runner(test_file, rules=default_rules_collection).run()
+        assert len(results) == failures
+        for result in results:
+            assert result.tag == "no-handler"