func isUpgrade()

in pkg/clusters/versions.go [124:158]

• 30 lines of code
• 10 McCabe index (conditional complexity)

func isUpgrade(desired, current string, valid []string, allowInPlace bool) error {
	if len(valid) == 0 {
		// Should not happen, but protects from out-of-bounds error.
		return fmt.Errorf("list of valid versions is empty: %v", valid)
	}

	var (
		desiredIndex = -1
		currentIndex = -1
	)
	for i, v := range valid {
		if v == desired {
			desiredIndex = i
		}
		if v == current {
			currentIndex = i
		}
	}
	if desiredIndex == -1 {
		return fmt.Errorf("desired version %s was not found; valid versions: %v", desired, valid)
	}
	if currentIndex == -1 {
		// The defalt version is no longer a valid version.
		// This can happen to node pools with auto-upgrade disabled.
		return nil
	}
	if allowInPlace && currentIndex == desiredIndex {
		return nil
	}
	if currentIndex <= desiredIndex {
		return fmt.Errorf("desired version %s must be newer than current version %s; valid versions: %v", desired, current, valid)
	}

	return nil
}