Add support for markdown-it plugins (#22)

* load markdown-it plugins
* test markdown-it plugins
* add section to readme on markdown plugins and options (#1)

Author: tkraak

README.md

@@ -84,6 +84,7 @@ Any of these plugins can be customized by passing options described below.
 | **delimiters** | Delimiters used for html-escaped expressions | `['{{', '}}']` |
 | **unescapeDelimiters** | Delimiters used for unescaped expressions | `['{{{', '}}}']` |
 | **markdown** | Options passed in to [markdown-it](https://github.com/markdown-it/markdown-it) constructor | `{ typographer: true, linkify: true }` |
+| **markdownPlugins** | Plugins to be loaded by [markdown-it](https://github.com/markdown-it/markdown-it) parser. See below for more details. | |
 | **content** | Options passed to the [reshape-content](https://github.com/reshape/content) plugin | `{ md: renderMarkdown, mdi: renderMarkdownInline }` |
 | **parser** | custom html parser if desired. pass `false` to use the default html parser | `sugarml` |
 | **retext** | Plugins to be passed to the [reshape-retext](https://github.com/reshape/retext) plugin | `[smartypants]` ([ref](https://github.com/wooorm/retext-smartypants)) |
@@ -129,6 +130,26 @@ Would render without additional paragraph wrappings or unexpected title renders:
 <p> Hello, I am #1 and this is <a href='#'>my link</a>.
 ```
 
+### Markdown Plugins
+
+You can pass an array of [markdown-it plugins](https://www.npmjs.com/browse/keyword/markdown-it-plugin) via the `markdownPlugins` option with or without their own options.
+
+```js
+const reshape = require('reshape')
+const standard = require('reshape-standard')
+const emoji = require('markdown-it-emoji')
+const anchor = require('markdown-it-anchor')
+const toc = require('markdown-it-table-of-contents')
+
+reshape(standard(markdownPlugins: [
+  emoji,
+  anchor,
+  [toc, { containerClass: 'toc' }]
+]))
+  .process(someHtml)
+  .then((res) => console.log(res.output()))
+```
+
 ### License & Contributing
 
 - Details on the license [can be found here](LICENSE.md)

lib/index.js

@@ -50,6 +50,10 @@ module.exports = function reshapeStandard (options = {}) {
   if (!contentOpt.md) {
     const markdownOpt = { typographer: true, linkify: true }
     const md = new MarkdownIt(Object.assign({}, markdownOpt, options.markdown))
+    // if the user has provided markdown-it plugins, load them into the parser instance
+    ;(options.markdownPlugins || []).forEach((plugin) => {
+      Array.isArray(plugin) ? md.use(...plugin) : md.use(plugin)
+    })
     contentOpt.md = md.render.bind(md)
     contentOpt.mdi = md.renderInline.bind(md)
   }

test/index.js

@@ -117,3 +117,18 @@ test('prependPlugins option', (t) => {
   t.truthy(out.plugins[0] === 'test')
   t.truthy(out2.plugins[0] === 'test')
 })
+
+test('markdownPlugins option', (t) => {
+  const plugins = [1, 2, 3]
+  let count = 0
+  function MarkdownIt () {}
+  MarkdownIt.prototype.use = (plugin) => {
+    t.truthy(plugins[count] === plugin)
+    count++
+  }
+  MarkdownIt.prototype.render = () => {}
+  MarkdownIt.prototype.renderInline = () => {}
+  const undo = standardRewired.__set__('MarkdownIt', MarkdownIt)
+  standardRewired({ markdownPlugins: plugins })
+  undo()
+})