refactor(toc_helper): utilize hexo-util (hexojs#3850)

* refactor(toc_helper): relpace cheerio with htmlparser2

* test(toc_helper): use classic for loop

* refactor(toc_helper): utilize tocObj

lib/plugins/helper/toc.js

@@ -1,35 +1,29 @@
 'use strict';
 
-let cheerio;
-const { escapeHTML } = require('hexo-util');
+const { tocObj } = require('hexo-util');
 
 function tocHelper(str, options = {}) {
-  if (!cheerio) cheerio = require('cheerio');
+  options = Object.assign({
+    max_depth: 6,
+    class: 'toc',
+    list_number: true
+  }, options);
 
-  const $ = cheerio.load(str);
-  const headingsMaxDepth = Object.prototype.hasOwnProperty.call(options, 'max_depth') ? options.max_depth : 6;
-  const headingsSelector = ['h1', 'h2', 'h3', 'h4', 'h5', 'h6'].slice(0, headingsMaxDepth).join(',');
-  const headings = $(headingsSelector);
+  const data = tocObj(str, { max_depth: options.max_depth });
 
-  if (!headings.length) return '';
+  if (!data.length) return '';
+
+  const className = options.class;
+  const listNumber = options.list_number;
 
-  const className = options.class || 'toc';
-  const listNumber = Object.prototype.hasOwnProperty.call(options, 'list_number') ? options.list_number : true;
   let result = `<ol class="${className}">`;
   const lastNumber = [0, 0, 0, 0, 0, 0];
   let firstLevel = 0;
   let lastLevel = 0;
 
-  function getId(ele) {
-    const id = $(ele).attr('id');
-    const $parent = $(ele).parent();
-    return id || ($parent.length < 1 ? null : getId($parent));
-  }
-
-  headings.each(function() {
-    const level = +this.name[1];
-    const id = getId(this);
-    const text = escapeHTML($(this).text());
+  for (let i = 0, len = data.length; i < len; i++) {
+    const el = data[i];
+    const { level, id, text } = el;
 
     lastNumber[level - 1]++;
 
@@ -67,7 +61,7 @@ function tocHelper(str, options = {}) {
     result += `<span class="${className}-text">${text}</span></a>`;
 
     lastLevel = level;
-  });
+  }
 
   for (let i = firstLevel - 1; i < lastLevel; i++) {
     result += '</li></ol>';

package.json

@@ -43,7 +43,6 @@
     "archy": "^1.0.0",
     "bluebird": "^3.5.2",
     "chalk": "^3.0.0",
-    "cheerio": "0.22.0",
     "hexo-cli": "^3.0.0",
     "hexo-front-matter": "^1.0.0",
     "hexo-fs": "^2.0.0",
@@ -71,6 +70,7 @@
     "@easyops/git-exec-and-restage": "^1.0.4",
     "chai": "^4.1.2",
     "chai-as-promised": "^7.1.1",
+    "cheerio": "0.22.0",
     "eslint": "^6.0.1",
     "eslint-config-hexo": "^4.0.0",
     "hexo-renderer-marked": "^2.0.0",