PostCSS Markdown Syntax

PostCSS syntax for parsing Markdown

Getting Started

First thing's first, install the module:

1npm install postcss-markdown --save-dev

If you want support SCSS/SASS/LESS/SugarSS syntax, you need to install the corresponding module.

• SCSS: postcss-scss
• SASS: postcss-sass
• LESS: postcss-less
• SugarSS: sugarss
• Stylus: postcss-styl

Use Cases

1const postcss = require("postcss");
2const syntax = require("postcss-markdown")({
3    // Enable support for HTML (default: true)
4    htmlInMd: true,
5    // syntax for parse scss (non-required options)
6    scss: require("postcss-scss"),
7    // syntax for parse less (non-required options)
8    less: require("postcss-less"),
9    // syntax for parse css blocks (non-required options)
10    css: require("postcss-safe-parser"),
11});
12const autoprefixer = require("autoprefixer");
13postcss([autoprefixer])
14    .process(source, { syntax: syntax })
15    .then(function (result) {
16        // An alias for the result.css property. Use it with syntaxes that generate non-CSS output.
17        result.content;
18    });

input:

# title

```css
::placeholder {
    color: gray;
}
```

output:

# title

```css
::-moz-placeholder {
    color: gray;
}
:-ms-input-placeholder {
    color: gray;
}
::placeholder {
    color: gray;
}
```

If you want support SCSS/SASS/LESS/SugarSS syntax, you need to install these module:

• SCSS: postcss-scss
• SASS: postcss-sass
• LESS: postcss-less
• SugarSS: sugarss
• Stylus: postcss-styl

Advanced Use Cases

Options

1const options = {
2    rules: [
3        {
4            // custom language
5            test: /^postcss$/i,
6            lang: "scss",
7        },
8        {
9            // custom language
10            test: /^customcss$/i,
11            lang: "custom",
12        },
13    ],
14
15    // custom parser for CSS (using `postcss-safe-parser`)
16    css: "postcss-safe-parser",
17    // custom parser for SASS (PostCSS-compatible syntax.)
18    sass: require("postcss-sass"),
19    // custom parser for SCSS (by module name)
20    scss: "postcss-scss",
21    // custom parser for LESS (by module path)
22    less: require.resolve("./node_modules/postcss-less"),
23    // custom parser for SugarSS
24    sugarss: require("sugarss"),
25    // custom parser for custom language
26    custom: require("postcss-custom-syntax"),
27};
28const syntax = require("postcss-markdown")(options);

Turning PostCSS off from within your Markdown

PostCSS can be temporarily turned off by using special comments in your Markdown. For example:

<!-- postcss-ignore -->
```css
a {
    color: red;
}
```

Linting with Stylelint

The main use case of this plugin is to apply linting with Stylelint to CSS (and CSS-like) code blocks in markdown file.

You can use it by configuring your stylelint config as follows:

1{
2    "overrides": [
3        {
4            "files": ["*.md", "**/*.md"],
5            "customSyntax": "postcss-markdown"
6        }
7    ]
8}

Editor integrations

Visual Studio Code

Use the stylelint.vscode-stylelint extension that Stylelint provides officially.

You have to configure the stylelint.validate option of the extension to check .md files, because the extension does not check the *.md file by default.

Example .vscode/settings.json:

1{
2  "stylelint.validate": [
3      ...,
4      // ↓ Add "markdown" language.
5      "markdown"
6  ]