1 files changed, 106 insertions, 0 deletions
diff --git a/src/ansiblelint/rules/no_changed_when.py b/src/ansiblelint/rules/no_changed_when.py
new file mode 100644
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+++ b/src/ansiblelint/rules/no_changed_when.py
@@ -0,0 +1,106 @@
+"""Implementation of the no-changed-when rule."""
+# 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.
+
+from __future__ import annotations
+
+import sys
+from typing import TYPE_CHECKING
+
+from ansiblelint.rules import AnsibleLintRule
+
+if TYPE_CHECKING:
+    from ansiblelint.errors import MatchError
+    from ansiblelint.file_utils import Lintable
+    from ansiblelint.utils import Task
+
+
+class CommandHasChangesCheckRule(AnsibleLintRule):
+    """Commands should not change things if nothing needs doing."""
+
+    id = "no-changed-when"
+    severity = "HIGH"
+    tags = ["command-shell", "idempotency"]
+    version_added = "historic"
+
+    _commands = [
+        "ansible.builtin.command",
+        "ansible.builtin.shell",
+        "ansible.builtin.raw",
+        "ansible.legacy.command",
+        "ansible.legacy.shell",
+        "ansible.legacy.raw",
+        "command",
+        "shell",
+        "raw",
+    ]
+
+    def matchtask(
+        self,
+        task: Task,
+        file: Lintable | None = None,
+    ) -> list[MatchError]:
+        result = []
+        # tasks in a block are "meta" type
+        if (
+            task["__ansible_action_type__"] in ["task", "meta"]
+            and task["action"]["__ansible_module__"] in self._commands
+            and (
+                "changed_when" not in task.raw_task
+                and "creates" not in task["action"]
+                and "removes" not in task["action"]
+            )
+        ):
+            result.append(self.create_matcherror(filename=file))
+        return result
+
+
+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(
+        ("file", "expected"),
+        (
+            pytest.param(
+                "examples/playbooks/rule-no-changed-when-pass.yml",
+                0,
+                id="pass",
+            ),
+            pytest.param(
+                "examples/playbooks/rule-no-changed-when-fail.yml",
+                3,
+                id="fail",
+            ),
+        ),
+    )
+    def test_rule_no_changed_when(
+        default_rules_collection: RulesCollection,
+        file: str,
+        expected: int,
+    ) -> None:
+        """Validate no-changed-when rule."""
+        results = Runner(file, rules=default_rules_collection).run()
+
+        for result in results:
+            assert result.rule.id == CommandHasChangesCheckRule.id, result
+        assert len(results) == expected