func matchVersion()

in tool/preprocess/match.go [175:223]
39 lines of code
15 McCabe index (conditional complexity)

func matchVersion(version string, ruleVersion string) (bool, error) {
	// Fast path, always match if the rule version is not specified
	if ruleVersion == "" {
		return true, nil
	}
	// Check if both rule version and package version are in sane
	if !strings.Contains(version, "v") {
		return false, errc.New(errc.ErrMatchRule,
			fmt.Sprintf("invalid version %v", version))
	}
	if !strings.Contains(ruleVersion, "[") ||
		!strings.Contains(ruleVersion, ")") ||
		!strings.Contains(ruleVersion, ",") ||
		strings.Contains(ruleVersion, "v") {
		return false, errc.New(errc.ErrMatchRule,
			fmt.Sprintf("invalid rule version %v", ruleVersion))
	}
	// Remove extra whitespace from the rule version string
	ruleVersion = strings.ReplaceAll(ruleVersion, " ", "")

	// Compare the version with the rule version, the rule version is in the
	// format [start, end), where start is inclusive and end is exclusive
	// and start or end can be omitted, which means the range is open-ended.
	ruleVersionStart, ruleVersionEnd := splitVersionRange(ruleVersion)
	switch {
	case ruleVersionStart != "v" && ruleVersionEnd != "v":
		// Full version range
		if semver.Compare(version, ruleVersionStart) >= 0 &&
			semver.Compare(version, ruleVersionEnd) < 0 {
			return true, nil
		}
	case ruleVersionStart == "v":
		// Only end is specified
		util.Assert(ruleVersionEnd != "v", "sanity check")
		if semver.Compare(version, ruleVersionEnd) < 0 {
			return true, nil
		}
	case ruleVersionEnd == "v":
		// Only start is specified
		util.Assert(ruleVersionStart != "v", "sanity check")
		if semver.Compare(version, ruleVersionStart) >= 0 {
			return true, nil
		}
	default:
		return false, errc.New(errc.ErrMatchRule,
			fmt.Sprintf("invalid rule version range %v", ruleVersion))
	}
	return false, nil
}