koki-develop/qiita-cli

package util

import (
    "bufio"
    "io"
    "strings"
    "unicode"

    "gopkg.in/yaml.v3"
)

func ReadMarkdown(r io.Reader, frontMatter interface{}) (string, error) {
    scanner := bufio.NewScanner(r)
    var fmLines []string
    var mdLines []string
    var fm bool

    for scanner.Scan() {
        line := scanner.Text()
        if strings.TrimRightFunc(line, unicode.IsSpace) == "---" {
            fm = !fm
            continue
        }

        if fm {
            fmLines = append(fmLines, line)
        } else {
            mdLines = append(mdLines, line)
        }
    }

    md := strings.TrimSpace(strings.Join(mdLines, "\n"))
    if len(fmLines) == 0 {
        return md, nil
    }

    if err := yaml.Unmarshal([]byte(strings.Join(fmLines, "\n")), frontMatter); err != nil {
        return "", err
    }

    return md, nil
}

func WriteMarkdown(w io.Writer, md string, frontMatter interface{}) error {
    y, err := yaml.Marshal(frontMatter)
    if err != nil {
        return err
    }
    if _, err := w.Write([]byte("---\n")); err != nil {
        return err
    }
    if _, err := w.Write(y); err != nil {
        return err
    }
    if _, err := w.Write([]byte("---\n")); err != nil {
        return err
    }
    if _, err := w.Write([]byte{'\n'}); err != nil {
        return err
    }
    if _, err := w.Write([]byte(md)); err != nil {
        return err
    }

    return nil
}