index.test.js

const MarkdownIt = require('markdown-it')
const MarkdownItClass = require('./index.js')
const attrs = require('markdown-it-attrs')

describe('markdown-it-class', () => {
  it('adds a class to corresponding tags', () => {
    const mapping = {
        h1: 'title',
        h2: 'subtitle'
      },
      mdtxt = '# Hello\n## World'
    htmltxt =
      '<h1 class="title">Hello</h1>\n<h2 class="subtitle">World</h2>'

    const md = new MarkdownIt()
    md.use(MarkdownItClass, mapping)

    expect(md.render(mdtxt).trim()).toBe(htmltxt)
  })

  it('adds classes to corresponding tags', () => {
    const mapping = {
        h1: ['title', 'is-4'],
        h2: ['subtitle', 'is-6']
      },
      mdtxt = '# Hello\n## World'
    htmltxt =
      '<h1 class="title is-4">Hello</h1>\n<h2 class="subtitle is-6">World</h2>'

    const md = new MarkdownIt()
    md.use(MarkdownItClass, mapping)

    expect(md.render(mdtxt).trim()).toBe(htmltxt)
  })

  it('adds classes to em tags', () => {
    const mapping = {
        em: 'tag',
      },
      mdtxt = '# There are three buttons, *red* *green* and *blue*.'
    htmltxt =
      '<h1>There are three buttons, <em class="tag">red</em> <em class="tag">green</em> and <em class="tag">blue</em>.</h1>'

    const md = new MarkdownIt()
    md.use(MarkdownItClass, mapping)

    expect(md.render(mdtxt).trim()).toBe(htmltxt)
  })
  
  it('adds classes to img tags', () => {
    const mapping = {
        img: 'tag',
      },
      mdtxt = '![alt text](http://placehold.it/720x480.jpg)'
    htmltxt =
      '<p><img src="http://placehold.it/720x480.jpg" alt="alt text" class="tag"></p>'

    const md = new MarkdownIt()
    md.use(MarkdownItClass, mapping)

    expect(md.render(mdtxt).trim()).toBe(htmltxt)
  })

  it('works with markdown-it-attrs', () => {
    const mapping = {
        h1: ['is-4', 'is-black'],
        h2: 'is-6'
      },
      mdtxt = '# Hello {.title}\n## World {.subtitle .is-dark}'
    htmltxt =
      '<h1 class="title is-4 is-black">Hello</h1>\n<h2 class="subtitle is-dark is-6">World</h2>'

    const md = new MarkdownIt()
    md.use(MarkdownItClass, mapping)
    md.use(attrs)

    expect(md.render(mdtxt).trim()).toBe(htmltxt)
  })
})