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1.5.9 • Public • Published

stylint - the stylus linter.

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As part of your project: npm install stylint --save-dev

As a cli tool: npm install stylint -g


NOTE: We are currently working on a 2.0 release. Bug fixing will not be a priority during this process, but we will try to make sure every bug is squashed after that.

Follow the project, milestone and issue for progress. Please contribute if you have the time! Both with code, but also with ideas and features.

The goal of 2.0 is to make the project more stable:

  • actual unit tests on the rules to avoid regressions, instead of coupling them to the tests of the core linter
  • a clearly defined API surface, making Stylint easy to depend on for external tools
  • a cleaner way of invoking Stylint programatically
  • a way of linting a string of code, not just files
  • simplify config (inspired by ESLint's config structure)

Sometime in the future™️ we will also provide extension points for custom rules, and maybe even automatically fix some violations, but that's a change that might take some time. These goals are more long-term though, short term the focus is on stability and integration with tools.

If you have any problems with the linter just create a ticket there and I will respond.

Same thing if you have any feature requests.

I will gladly accept pull requests if you want to do the work yourself.

you can also ping me here


-h or --help Display list of commands

-w or --watch Watch file or directory and run lint on change

-c or --config Pass in location of custom config file

-v or --version Display current version

Example cli Usage:

stylint Run stylint on cwd

stylint path/to/filename.styl Run stylint on a file

stylint path/to/dir --watch Watch dir, run stylint on file change

stylint --help Get list of commands

stylint --version Get version number

stylint --config path/to/config/.configrc Run stylint with custom config settings

stylint --reporter stylint-reporter-module Run stylint with custom reporter module

stylint styl/ --watch -c path/to/config/.configrc Watch dir, use custom config

Non CLI Usage

I'll be the first to admit that the syntax is a bit weird, but it works just fine.

const stylint = require('stylint')('path/to/stylus/', {
        brackets: 'always',
        namingConvention: 'BEM',
        semicolons: 'always'
}, callbackFn).create();

API docs are in the docs/ folder


You can use the CLI with gulp-shell like below:

gulp.task('stylint', shell.task([
        'stylint path/to/styl/ -c .stylintrc'

Or just use gulp-stylint

var gulp = require('gulp');
var stylint = require('gulp-stylint');
gulp.task('default', function () {
        return gulp.src('src/*.styl')


You can use grunt-stylint

    stylint: {
        options: {
            config: {
                colons: 'never'
        src: ['src/**/*.styl']


You can use stylint-loader

module.exports = {
    // ...
    module: {
        preLoaders: [
                test: /\.styl$/,
                loader: 'stylint'
        loaders: [
                test: /\.styl$/,
                loader: 'style!css!stylus'
    // ...

As Part of Your Workflow

Stylint integrations with multiple IDEs are available.

Why Write This Tool?

Stylus is my CSS pre-processor of choice and the lack of a decent linter (or really, any linter) was an annoying pain point. So I thought I'd try my hand at writing what I thought my ideal linter would look like.

Why Use This Tool?

To catch little mistakes (duplication of rules for instance) and to enforce a code style guide. This is particularly important with Stylus, which is unopinionated when it comes to syntax. Like Stylus itself, this linter opts for flexibility over rigidity.


The following is a list of all options available to stylint.

Note that customProperties and mixins are aliases

    "blocks": false,
    "brackets": "never",
    "colons": "always",
    "colors": "always",
    "commaSpace": "always",
    "commentSpace": "always",
    "cssLiteral": "never",
    "customProperties": [],
    "depthLimit": false,
    "duplicates": true,
    "efficient": "always",
    "exclude": [],
    "extendPref": false,
    "globalDupe": false,
    "groupOutputByFile": true,
    "indentPref": false,
    "leadingZero": "never",
    "maxErrors": false,
    "maxWarnings": false,
    "mixed": false,
    "mixins": [],
    "namingConvention": false,
    "namingConventionStrict": false,
    "none": "never",
    "noImportant": true,
    "parenSpace": false,
    "placeholders": "always",
    "prefixVarsWithDollar": "always",
    "quotePref": false,
    "reporterOptions": {
        "columns": ["lineData", "severity", "description", "rule"],
        "columnSplitter": "  ",
        "showHeaders": false,
        "truncate": true
    "semicolons": "never",
    "sortOrder": "alphabetical",
    "stackedProperties": "never",
    "trailingWhitespace": "never",
    "universal": false,
    "valid": true,
    "zeroUnits": "never",
    "zIndexNormalize": false

Custom Configuration

Stylint will try to find a custom configuration in many different places before it falls back to the default config (see above). It goes in this order of importance:

  1. Pass in via function parameter (ie, using stylint programmatically)
  2. Passed in via command line flag
  3. Passed in via package.json, either as an object or path to a .stylintrc file
  4. Via a .stylintrc file, starting from the cwd and working up to the home user directory
  5. If all of the above fails, use the default config

You can also use the -c or --config flags to pass in the location of your custom .stylintrc config file if it resides somewhere else.

You can use the stylintrc property in your package.json to point to a .stylintrc file, or just directly pass in your config

If requiring Stylint ( as opposed to using it via the cli ), the 2nd param is the config object.


Stylint has 2 levels of output, Warnings and Errors. All Stylint rules optionally take an object, allowing you to set it to be an Error. Combined with the maxWarnings and maxErrors properties, you can be very flexible about say, code style but strict on things like code duplication.


        "brackets": {
                "expect": "never",
                "error": true
        "colons": {
                "expect": "always",
                "error": true

Custom Reporters

Stylint console output can be modified with the use of a reporter. Feel free to write your own (no matter how outlandish) and I'll add it here.

Excluding files, directories, and code blocks from the linter


Before linting Stylint will look for a .stylintignore file in the current working directory, and will ignore files listed there. The files should be formatted in the same way you would use .gitignore or .eslintignore

For reference, it looks like this:


the package.json approach

You can also exclude files/directories via your package.json by adding a stylintignore property.

For reference:

    "stylintignore": ["path/to/file.styl", "path/to/directory/"],

the config approach

see config documentation below for how to use the exclude option via .stylintrc or your passed in config object

stylint toggle ( inline comment: @stylint off || @stylint on )

Disable linting for a particular block of code by placing @stylint off in a line comment. Re-enable by placing @stylint on in a line comment further down. Stylint will not test any lines until turned back on. Use this to suppress warnings on a case-by-case basis. By default the linter will check every line except for @css blocks or places where certain rules have exceptions.

For example, let's say you want to enforce namingConvention: "lowercase_underscore", but you're also styling elements from the Bootstrap framework. You can use the @stylint off toggle to prevent warnings in places where you're referencing Bootstrap classes.


.button_block {
// @stylint off
.button_block .btn-default {
// @stylint on

ignore line toggle ( inline comment: @stylint ignore )

A toggle that works like @stylint off, but just for one line. Useful for cases where you want to include fallback css for browser support.


    background-imageurl('path/to/png.png'// @stylint ignore
    cursorpointer // @stylint ignore
    cursor: zoom-in

transparent mixins / custom properties ( Array )

In Stylus you have the option of using mixins transparently, like css properties. Because of how Stylus' syntax works, this rule also allows you to add adhoc support for custom properties as needed by just added the name of the property to this array.

>>> config file
    "customProperties": ['myCustomProperty']
>>> example.styl
    myCustomProperty: 5px

Where myCustomProperty is a mixin that takes a px val as it's parameter.

If you use nib, size, absolute, and fixed are often used in this way. If you use css-modules, composes is another one.

Because of nib's widespread use, and css-modules growing popularity, the above 4 custom properties are supported by Stylint by default.

blocks ( default: false, 'always' || 'never' || false )

When 'always' expect the @block keyword when defining block variables. When 'never', expect no @block keyword when defining block variables. When false, do not check either way.

Example if 'always': prefer my-block = @block over my-block =

Example if 'never': prefer my-block = over my-block = @block

brackets ( default: 'never', 'always' || 'never' || false )

When 'always', expect {} when declaring a selector. When 'never', expect no brackets when declaring a selector.

Example if 'always': prefer .some-class-name { over .some-class-name

Example if 'never': prefer .some-class-name over .some-class-name {

colons ( default: 'always', 'always' || 'never' || false )

When 'always', expect : when declaring a property. When 'never', expect no : when declaring a property.

Example if 'always': prefer margin: 0 over margin 0

Example if 'never: prefer margin 0 over margin: 0

colors ( default: 'always' || false )

When 'always', enforce variables when defining hex values

Example if true: prefer color $red over color #f00

commaSpace ( default: 'always', 'always' || 'never' || false )

Enforce or disallow spaces after commas.

Example if always: prefer rgba(0, 0, 0, .18) over rgba(0,0,0,.18)

Example if never: prefer rgba(0,0,0,.18) over rgba(0, 0, 0, .18)

commentSpace ( default: 'always', 'always' || 'never' || false )

Enforce or disallow spaces after line comments

Example if always: prefer // comment over //comment

Example if never: prefer //comment over // comment

cssLiteral ( default: 'never', 'never' || false )

By default Stylint ignores @css blocks. If set to true however, it will throw a warning if @css is used.

Example if 'never': @css will throw a warning

depthLimit ( default: false, number or false )

Set the max selector depth. If set to 4, max selector depth will be 4 indents. Pseudo selectors like &:first-child or &:hover won't count towards the limit.

Set to false if you don't want to check for this.

duplicates ( default: true, true || false )

Checks if selector or property duplicated unnecessarily. By default, only checks on a file-by-file basis, but if globalDupes: true is set, then it will also check for duplicates globally (for root values only).

Example if true: the following will throw a warning:

    margin 0
    margin 5px

efficient ( default: 'always', 'always' || 'never' || false )

Check for places where properties can be written more efficiently.

Example if always: prefer margin 0 over margin 0 0

Example if never: prefer margin 0 0 over margin 0

exclude ( default: [], array of strings )

Exclude certain file patterns from linting.

Example: ["vendor/**/*", "node_modules/**/*"] will exclude all files in the vendor or node_modules directory.

extendPref ( default: false, '@extend' || '@extends' || false )

Pass in either @extend or @extends and then enforce that. Both are valid in Stylus. It doesn't really matter which one you use. I prefer @extends myself.

Example if set to @extends: prefer @extends $some-var over @extend $some-var

Example if set to @extend: prefer @extend $some-var over @extend $some-var

globalDupe ( default: false, true || false )

Works in conjunction with duplicates. Does nothing on its own. If false, duplicates will check for dupes within individual files only. If true, duplicates will check for dupes across all files.

Example if true: the following will throw a warning

>>> file1.styl
    margin 0
>>> file2.styl
    margin 5px

groupOutputByFile ( default: true, true || false )

Stylint's default setting groups errors and warnings by file when outputting. You can disable this if you want

Example if true:

    73:32      warning  mixed spaces and tabs  mixed
    78:30   error    missing semicolon      semicolons
    16     warning  prefer alphabetical when sorting properties  sortOrder

Example if false:

    73:32      warning  mixed spaces and tabs  mixed
    78:30   error    missing semicolon      semicolons
    16     warning  prefer alphabetical when sorting properties  sortOrder

indentPref ( default: false, number or false )

This works in conjunction with depthLimit. If you indent with spaces this is the number of spaces you indent with. If you use hard tabs, set this value to false.

If you set this to a number, it will output warnings/errors if you the # of spaces used for indenting differs from the number set.

By default this value is false, so if you indent with spaces you'll need to manually set this value in a custom .stylintrc file.

Example if 2: prefer /s/smargin: 0 over /s/s/smargin: 0

leadingZero ( default: 'never', 'always' || 'never' || false )

Enforce or disallow unnecessary leading zeroes on decimal points.

Example if always: prefer rgba( 0, 0, 0, 0.5 ) over rgba( 0, 0, 0, .5 )

Example if never: prefer rgba( 0, 0, 0, .5 ) over rgba( 0, 0, 0, 0.5 )

maxErrors ( default: false, number || false )

Set 'max' number of Errors.

maxWarnings ( default: false, number || false )

Set 'max' number of Warnings.

mixed ( default: false, boolean, relies on indentPref )

Returns true if mixed spaces and tabs are found. If a number is passed to indentPref, it assumes soft tabs (ie, spaces), and if false is passed to indentPref it assumes hard tabs.

If soft tabs, outputs warning/error if hard tabs used. If hard tabs, outputs warning/error if unnecessary extra spaces found.

Example if indentPref: 4 and mixed: true: prefer \s\s\s\smargin\s0 over \tmargin\s0

Example if indentPref: 2 and mixed: true: prefer \s\smargin\s0 over \tmargin\s0

Example if indentPref: false and mixed: true: prefer \tmargin\s0 over \s\s\s\smargin\s0

namingConvention ( default: false, false | 'lowercase-dash' | 'lowercase_underscore' | 'camelCase' | 'BEM' )

Enforce a particular naming convention when declaring classes, ids, and variables. Throws a warning if you don't follow the convention.

Example if set to 'lowercase-dash': prefer $var-name over $var_name or $varName

Example if set to 'lowercase_underscore': prefer $var_name over $var-name or $varName

Example if set to 'camelCase': prefer $varName over $var_name or $var-name

Example if set to 'BEM': prefer $var__like--this over $var_name or $varName

namingConventionStrict ( default: false, true || false )

By default, namingConvention only looks at variable names. If namingConventionStrict is set to true, namingConvention will also look at class and id names.

If you have a lot of 3rd party css you can't change you might want to leave this off.

none ( default: 'never'. options: 'always' || never' || false )

If 'always' check for places where none used instead of 0. If 'never' check for places where 0 could be used instead of none.

Example if 'always': prefer border none over border 0

Example if 'never': prefer outline 0 over outline none

noImportant ( default: true, true || false )

If true, show warning when !important is found.

Example if true: the following will throw a warning

    color red !important

parenSpace ( default: false, 'always' || 'never' || false )

Enforce or disallow use of extra spaces inside parens.

Example if always: prefer my-mixin( $myParam ) over my-mixin($myParam)

Example if never: prefer my-mixin($myParam) over my-mixin( $myParam )

placeholder ( default: 'always', 'always' || 'never' || false )

Enforce extending placeholder vars when using @extend(s)

Example if always: prefer @extends $placeholder over $extends .some-class

Example if never: prefer @extends .some-class over $extends $placeholder

prefixVarsWithDollar ( default: 'always', 'always' || 'never' || false )

Enforce use of $ when defining a variable. In Stylus using a $ when defining a variable is optional, but is a good idea if you want to prevent ambiguity. Not including the $ sets up situations where you wonder: "Is this a variable or a value?" For instance: padding $default is easier to understand than padding default.

Yes, default isn't an acceptable value for padding, but at first glance you might not catch that since it just looks like a value. And now if you try to set cursor default, it's not going to behave the way you expect. All this pain and heartache could've been avoided if you just used a $.

Example if always: prefer $my-var = 0 over my-var = 0

Example if never: prefer my-var = 0 over $my-var = 0

quotePref ( default: false, 'single' || 'double' || false )

Enforce consistent quotation style.

Example if 'single': prefer $var = 'some string' over $var = "some string"

Example if 'double': prefer $var = "some string" over $var = 'some string'

reporterOptions ( Object )

If using the default reporter, Stylint uses columnify when outputting warnings and errors (only if you have groupOutputByFile set to true). See columnify for more details. Using this option, you can easily customize the output (to an extent) without having to install a separate reporter.

Default options:

    columns: ['lineData', 'severity', 'description', 'rule'],
    columnSplitter: '  ',
    showHeaders: false,
    truncate: true

semicolons ( default: 'never', 'always' || 'never' || false )

Enforce or disallow semicolons

Example if always: prefer margin 0; over margin 0

Example if never: prefer margin 0 over margin 0;

sortOrder ( default: 'alphabetical', 'alphabetical' || 'grouped' || [Array] || false )

Enforce a particular sort order when declaring properties. Throws a warning if you don't follow the order. If set to false, allow any order.

Example if 'alphabetical':

prefer this:

    display block
    float left
    position absolute
    right 10px
    top 0

over this:

    position absolute
    top 0
    right 10px
    display block
    float left

Example if 'grouped' (based on predefined grouped ordering):

prefer this:

    position absolute
    top 0
    right 10px
    display block
    float left

over this:

    display block
    float left
    position absolute
    right 10px
    top 0

Example if [ 'margin', 'padding', 'float', 'position' ]:

prefer this:

    margin 0
    padding 0
    float left
    position absolute
    right 10px
    top 0
    display block

over this:

    display block
    float left
    position absolute
    right 10px
    top 0
    margin 0
    padding 0

When set to 'grouped' or {Array} throws a warning if properties that are not defined in the ordering array are not after those that should be ordered.

stackedProperties ( default: 'never', 'never' || false )

No one-liners. Enforce putting properties on new lines.

Example if never: prefer

    padding 0


.className { padding 0 }

trailingWhitespace ( default: 'never', 'never' || false )

If false, ignores trailing white space. If 'never', trailing white space will throw a warning.

universal ( default: false, 'never' || false )

Looks for instances of the inefficient * selector. Lots of resets use this, for good reason (resetting box model), but past that you really don't need this selector, and you should avoid it if possible.

Example if never, disallow the following:

div *
        margin 0

valid ( default: true, true || false )

Check that a property is valid CSS or HTML.

Example if true: marg 0 will throw a warning, prefer margin 0

Example if true: divv will throw a warning, prefer div

zeroUnits ( default: 'never', 'always' || 'never' || false )

Looks for instances of 0px. You don't need the px. Checks all units, not just px.

Example if always: prefer margin-right 0px over margin-right 0

Example if never: prefer margin-right 0 over margin-right 0em

zIndexNormalize ( default: false, number or false )

Enforce some (very) basic z-index sanity. Any number passed in will be used as the base for your z-index values. Throws an error if your value is not normalized.

Example if set to 5: prefer z-index 10 over z-index 9 Example if set to 10: prefer z-index 20 over z-index 15 Example if set to 50: prefer z-index 100 over z-index 75


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