Prettier now includes support for prettifying Markdown (including code blocks!), so as such, I'd recommend using the official Prettier instead. See the release notes for more information

A simple utility and CLI to run prettier on code blocks within Markdown, leaving any non-code blocks untouched.

Currently works on the following languages (basically everything prettier supports!):

• JavaScript
• TypeScript
• JSON
• CSS
• SASS
• LESS
• GraphQL

yarn global add @dschau/prettier-markdown

Command line usage is simple. All options (besides --dry, which will not write files to disk) are passed directly through to prettier.

prettier-markdown src/**/*.md README.md --single-quote --trailing-comma es5

Usage is fairly simple. An array of markdown files are passed, as well as any prettier options, and prettier is run on the specified files.

const path = require('path');
const { prettierMarkdown } = require('@dschau/prettier-markdown');

prettierMarkdown(
  ['README.md', 'blog/posts/2017-01-01-hello-world/index.md'].map(file =>
    path.join(process.cwd(), file)
  )
).then(files => {
  // array of files that were written
});

Note that line highlights (e.g. like the below) are kept intact and the block is still prettified!

```javascript {1-2}
const a =   'b';
const b =   'c';

  alert('hello world');
```

Frontmatter, i.e. in a Gastby blog post, is preserved as authored.

---
title: Hello World
tags:
  - Some Tag
  - Another Tag
---

```javascript
// this will be prettified
var a =    'a';

```