func runTests()

in tooling/prometheus-rules/main.go [199:247]
41 lines of code
9 McCabe index (conditional complexity)

func runTests(inputRules []alertingRuleFile) error {
	dir, err := os.MkdirTemp("/tmp", "prom-rule-test")
	if err != nil {
		return fmt.Errorf("error creating tempdir %v", err)
	}
	defer func() {
		os.RemoveAll(dir)
	}()

	logrus.Debugf("Created tempdir %s", dir)

	for _, irf := range inputRules {
		if irf.testFileBaseName == "" {
			continue
		}
		ruleGroups, err := yaml.Marshal(irf.rules.Spec)
		if err != nil {
			return fmt.Errorf("error Marshalling rule groups %v", err)
		}

		tmpFile := fmt.Sprintf("%s%s%s", dir, string(os.PathSeparator), irf.fileBaseName)

		err = os.WriteFile(tmpFile, ruleGroups, 0644)
		if err != nil {
			return fmt.Errorf("error writing rule groups file %v", err)
		}

		fileNameParts := strings.Split(irf.fileBaseName, ".")
		if len(fileNameParts) != 2 {
			return fmt.Errorf("missing filename extension or using '.' in filename")
		}

		testFile := filepath.Join(dir, irf.testFileBaseName)
		err = os.WriteFile(testFile, irf.testFileContent, 0644)
		if err != nil {
			return fmt.Errorf("error writing rule groups test file %v", err)
		}
		logrus.Debugf("running test %s", irf.testFileBaseName)
		cmd := exec.Command("promtool", "test", "rules", testFile)
		output, err := cmd.CombinedOutput()
		if err != nil {
			logrus.Error(string(output))
			return fmt.Errorf("error running promtool %v", err)
		}

	}

	return nil
}