Method runGofmt

dev/devcam/hook.go:182–227

runGofmt runs the external gofmt command over the local version of staged files. It returns the files that need gofmting.

()

// runGofmt runs the external gofmt command over the local version of staged files.
// It returns the files that need gofmting.
func (c *hookCmd) runGofmt() (files []string, err error) {
	repo, err := repoRoot()
	if err != nil {
		return nil, err
	}
	if !strings.HasSuffix(repo, string(filepath.Separator)) {
		repo += string(filepath.Separator)
	}

	out, err := cmdOutputDirErr(".", "git", "diff-index", "--name-only", "--diff-filter=ACM", "--cached", "HEAD", "--", ":(glob)**/*.go", ":!/vendor/")
	if err != nil {
		return nil, err
	}
	indexFiles := addRoot(repo, nonBlankLines(out))
	if len(indexFiles) == 0 {
		return
	}

	args := []string{"-l"}
	// TODO(mpl): it would be nice to TrimPrefix the pwd from each file to get a shorter output.
	// However, since git sets the pwd to GIT_DIR before running the pre-commit hook, we lost
	// the actual pwd from when we ran `git commit`, so no dice so far.
	args = append(args, indexFiles...)

	if c.verbose {
		fmt.Fprintln(cmdmain.Stderr, commandString("gofmt", args))
	}
	cmd := exec.Command("gofmt", args...)
	var stdout, stderr bytes.Buffer
	cmd.Stdout = &stdout
	cmd.Stderr = &stderr
	err = cmd.Run()

	if err != nil {
		// Error but no stderr: usually can't find gofmt.
		if stderr.Len() == 0 {
			return nil, fmt.Errorf("invoking gofmt: %v", err)
		}
		return nil, fmt.Errorf("%s: %v", stderr.String(), err)
	}

	// Build file list.
	files = lines(stdout.String())
	sort.Strings(files)
	return files, nil
}

func printf(format string, args ...interface{}) {
	cmdmain.Errorf(format, args...)