func readGithubOwners()

in dev/codeowners/codeowners.go [99:137]

• 34 lines of code
• 8 McCabe index (conditional complexity)

func readGithubOwners(codeownersPath string) (*githubOwners, error) {
	f, err := os.Open(codeownersPath)
	if err != nil {
		return nil, fmt.Errorf("failed to open %q: %w", codeownersPath, err)
	}
	defer f.Close()

	codeowners := githubOwners{
		owners: make(map[string][]string),
		path:   codeownersPath,
	}

	scanner := bufio.NewScanner(f)
	lineNumber := 0
	for scanner.Scan() {
		lineNumber++
		line := strings.TrimSpace(scanner.Text())
		if len(line) == 0 || strings.HasPrefix(line, "#") {
			continue
		}
		fields := strings.Fields(line)
		if len(fields) == 1 {
			err := codeowners.checkSingleField(fields[0])
			if err != nil {
				return nil, fmt.Errorf("invalid line %d in %q: %w", lineNumber, codeownersPath, err)
			}
			continue
		}
		path, owners := fields[0], fields[1:]

		// It is ok to overwrite because latter lines have precedence in these files.
		codeowners.owners[path] = owners
	}
	if err := scanner.Err(); err != nil {
		return nil, fmt.Errorf("scanner error: %w", err)
	}

	return &codeowners, nil
}