DEVX-145: feat: extract reusable components from infra and grm into devx

tests/unit/test_tools_check_alert_rules.py

@@ -0,0 +1,103 @@
+"""Unit tests for devx.tools.check_alert_rules."""
+
+from __future__ import annotations
+
+from pathlib import Path
+from unittest.mock import MagicMock, patch
+
+from click.testing import CliRunner
+
+from devx.tools.check_alert_rules import main
+
+
+class TestMain:
+    def test_skip_when_promtool_not_found(self, tmp_path: Path):
+        """Should exit 0 and print skip message when promtool is not on PATH."""
+        with patch("shutil.which", return_value=None):
+            runner = CliRunner()
+            result = runner.invoke(main, ["--template-path", str(tmp_path)])
+        assert result.exit_code == 0
+        assert "promtool not found" in result.output
+
+    def test_validates_rules_successfully(self, tmp_path: Path):
+        """Should exit 0 when promtool reports SUCCESS."""
+        (tmp_path / "alert-rules.yml.j2").write_text("groups: []")
+        mock_result = MagicMock()
+        mock_result.returncode = 0
+        mock_result.stdout = "Checking /tmp/test.yml\n  SUCCESS: 60 rules found\n"
+        mock_result.stderr = ""
+        with patch("shutil.which", return_value="/usr/bin/promtool"):
+            with patch("subprocess.run", return_value=mock_result):
+                runner = CliRunner()
+                result = runner.invoke(main, ["--template-path", str(tmp_path)])
+        assert result.exit_code == 0
+
+    def test_fails_on_promtool_error(self, tmp_path: Path):
+        """Should exit non-zero when promtool reports an error."""
+        (tmp_path / "alert-rules.yml.j2").write_text("groups: []")
+        mock_result = MagicMock()
+        mock_result.returncode = 1
+        mock_result.stdout = ""
+        mock_result.stderr = "Error: invalid template function 'default'\n"
+        with patch("shutil.which", return_value="/usr/bin/promtool"):
+            with patch("subprocess.run", return_value=mock_result):
+                runner = CliRunner()
+                result = runner.invoke(main, ["--template-path", str(tmp_path)])
+        assert result.exit_code != 0
+
+    def test_uses_correct_template_path(self, tmp_path: Path):
+        """Should render the specified template from the given path."""
+        (tmp_path / "alert-rules.yml.j2").write_text("groups: []")
+        captured_args = []
+
+        def fake_run(args, **kwargs):
+            captured_args.append(args)
+            mock = MagicMock()
+            mock.returncode = 0
+            mock.stdout = "SUCCESS"
+            mock.stderr = ""
+            return mock
+
+        with patch("shutil.which", return_value="/usr/bin/promtool"):
+            with patch("subprocess.run", side_effect=fake_run):
+                runner = CliRunner()
+                runner.invoke(main, ["--template-path", str(tmp_path)])
+        assert captured_args[0][0] == "promtool"
+        assert captured_args[0][1] == "check"
+        assert captured_args[0][2] == "rules"
+
+    def test_custom_template_name(self, tmp_path: Path):
+        """Should render a custom template name."""
+        (tmp_path / "custom-rules.yml.j2").write_text("groups: []")
+        mock_result = MagicMock()
+        mock_result.returncode = 0
+        mock_result.stdout = "SUCCESS"
+        mock_result.stderr = ""
+        with patch("shutil.which", return_value="/usr/bin/promtool"):
+            with patch("subprocess.run", return_value=mock_result):
+                runner = CliRunner()
+                result = runner.invoke(
+                    main, ["--template-path", str(tmp_path), "--template-name", "custom-rules.yml.j2"]
+                )
+        assert result.exit_code == 0
+
+    def test_template_vars_passed(self, tmp_path: Path):
+        """Should pass template variables to the render call."""
+        (tmp_path / "alert-rules.yml.j2").write_text("grafana: {{ grafana_base_url }}\ngroups: []")
+        mock_result = MagicMock()
+        mock_result.returncode = 0
+        mock_result.stdout = "SUCCESS"
+        mock_result.stderr = ""
+        with patch("shutil.which", return_value="/usr/bin/promtool"):
+            with patch("subprocess.run", return_value=mock_result):
+                runner = CliRunner()
+                result = runner.invoke(
+                    main,
+                    [
+                        "--template-path",
+                        str(tmp_path),
+                        "--var",
+                        "grafana_base_url=https://grafana.test.example.com",
+                    ],
+                )
+        assert result.exit_code == 0