fix: use explicit commit hash for docker package versioning (#856)

tests/unit/test_version.py

@@ -0,0 +1,56 @@
+# SPDX-FileCopyrightText: © Jens Bergmann and contributors
+# SPDX-License-Identifier: AGPL-3.0-or-later
+# SPDX-ArtifactOfProjectHomePage: https://github.com/Second-Hand-Friends/kleinanzeigen-bot/
+import importlib
+from datetime import datetime, timezone
+from unittest.mock import MagicMock, patch
+
+import pytest
+
+import version
+
+
+class TestVersion:
+    def test_get_version_prefers_git_commit_hash_env_var(self, monkeypatch:pytest.MonkeyPatch) -> None:
+        """Use explicit build metadata when present."""
+        monkeypatch.setenv("GIT_COMMIT_HASH", "abc1234")
+
+        with patch("version.shutil.which") as which_mock, patch("version.subprocess.run") as run_mock:
+            assert version.get_version() == f"{datetime.now(timezone.utc).year}+abc1234"
+
+        which_mock.assert_not_called()
+        run_mock.assert_not_called()
+
+    def test_get_version_falls_back_to_git(self, monkeypatch:pytest.MonkeyPatch) -> None:
+        """Resolve the version from git metadata when no override is provided."""
+        monkeypatch.delenv("GIT_COMMIT_HASH", raising = False)
+        result = MagicMock(stdout = "deadbee\n")
+
+        with patch("version.shutil.which", return_value = "/usr/bin/git") as which_mock, patch("version.subprocess.run", return_value = result) as run_mock:
+            assert version.get_version() == f"{datetime.now(timezone.utc).year}+deadbee"
+
+        which_mock.assert_called_once_with("git")
+        run_mock.assert_called_once_with(
+            ["/usr/bin/git", "rev-parse", "--short", "HEAD"],
+            check = True,
+            capture_output = True,
+            text = True,
+        )
+
+    def test_get_version_raises_when_git_is_missing(self, monkeypatch:pytest.MonkeyPatch) -> None:
+        """Fail clearly when no explicit hash and no git executable are available."""
+        monkeypatch.delenv("GIT_COMMIT_HASH", raising = False)
+
+        with patch("version.shutil.which", return_value = None), pytest.raises(RuntimeError, match = "set GIT_COMMIT_HASH or build from a valid git checkout"):
+            version.get_version()
+
+    def test_get_version_raises_when_git_head_is_unavailable(self, monkeypatch:pytest.MonkeyPatch) -> None:
+        """Fail clearly when git exists but repository metadata is unavailable."""
+        monkeypatch.delenv("GIT_COMMIT_HASH", raising = False)
+        called_process_error = getattr(importlib.import_module("subprocess"), "CalledProcessError")
+
+        with patch("version.shutil.which", return_value = "/usr/bin/git"), patch(
+            "version.subprocess.run",
+            side_effect = called_process_error(128, ["/usr/bin/git", "rev-parse", "--short", "HEAD"]),
+        ), pytest.raises(RuntimeError, match = "set GIT_COMMIT_HASH or build from a valid git checkout"):
+            version.get_version()