Lint markdown with customized rule by JavaScript

Recently, I have a repository with a lot of markdown files. Anduin2017/HowToCook: 程序员在家做饭方法指南。Programmer's guide about how to cook at home (Chinese only). (github.com)

I installed some markdown lint plugins. However, there are some customized need for me to lint files.

I think it might be a good idea to lint it with node JS, since it configures easily in GitHub pipeline and works with some advanced OO features.

Put a package.json in the root folder:

{
	"name": "how-to-cook",
	"description": "程序员在家做饭方法指南。Programmer's guide about how to cook at home (Chinese).",
	"version": "1.1.0",
	"author": "Anduin2017",
	"dependencies": {
		"textlint": "^12.1.0",
		"textlint-rule-ja-space-between-half-and-full-width": "^2.2.0",
		"textlint-rule-zh-half-and-full-width-bracket": "^1.1.0"
	},
	"devDependencies": {
		"glob": "^7.2.0"
	}
}

Put a file here:

const util = require("util");
const glob = util.promisify(require('glob'));
const fs = require("fs").promises;
const path = require('path');


async function main() {
    var errors = [];
    var directories = await glob(__dirname + '../../dishes/**/*.md');

    for (var filePath of directories) {
        var data = await fs.readFile(filePath, 'utf8');
        var filename = path.parse(filePath).base.replace(".md","");

        dataLines = data.split('\n').map(t => t.trim());
        titles = dataLines.filter(t => t.startsWith('#'));
        secondTitles = titles.filter(t => t.startsWith('## '));

        if (dataLines.filter(line => line.includes(' 勺')).length > 0) {
            errors.push(`File ${filePath} is invalid! 勺 is not an accurate unit!`);
        }
        if (titles[0].trim() != "# " + filename + "的做法") {
            errors.push(`File ${filePath} is invalid! It's title should be: ${"# " + filename + "的做法"}! It was ${titles[0].trim()}!`);
            continue;
        }
        if (secondTitles.length != 4) {
            errors.push(`File ${filePath} is invalid! It doesn't has 4 second titles!`);
            continue;
        }
        if (secondTitles[0].trim() != "## 必备原料和工具") {
            errors.push(`File ${filePath} is invalid! The first title is NOT 必备原料和工具! It was ${secondTitles[0]}!`);
        }
        if (secondTitles[1].trim() != "## 计算") {
            errors.push(`File ${filePath} is invalid! The second title is NOT 计算!`);
        }
        if (secondTitles[2].trim() != "## 操作") {
            errors.push(`File ${filePath} is invalid! The thrid title is NOT 操作!`);
        }
        if (secondTitles[3].trim() != "## 附加内容") {
            errors.push(`File ${filePath} is invalid! The fourth title is NOT 附加内容!`);
        }

        var mustHave = '如果您遵循本指南的制作流程而发现有问题或可以改进的流程，请提出 Issue 或 Pull request 。';
        var mustHaveIndex = dataLines.indexOf(mustHave);
        if (mustHaveIndex < 0) {
            errors.push(`File ${filePath} is invalid! It doesn't have necessary scentence.`);
        }
    }
    
    if (errors.length > 0) {
        for (var error of errors) {
            console.error(error + "\n");
        }

        var message = `Found ${errors.length} errors! Please fix!`;
        throw new Error(message);
    }
}

main();

To lint it in CI, create a file to .github/workflows/ci.yml.

Edit the content like this:

name: Continuous Integration

on:
  pull_request:
    branches: [ master ]

jobs:
  markdown-lint:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v2
      - uses: actions/setup-node@v2
        with:
          node-version: '16'
          cache: 'npm'
      - name: Install packages
        run: sudo gem install mdl
      - name: Lint markdown files
        run: mdl . -r ~MD036,~MD024,~MD004,~MD029
      - run: npm install
      - run: node .github/manual_lint.js
        # Suppress 036 Emphasis used instead of a header
        # Suppress 024 Multiple headers with the same content