StyleStats

StyleStats is a Node.js library to collect CSS statistics.

Installation

StyleStats works on Node.js 0.10.x

$ npm install -g stylestats

Usage

$ stylestats path/to/stylesheet.css
StyleStats!
┌─────────────────────────────────┬────────────────────┐
│ Style Sheets                    │ 1                  │
├─────────────────────────────────┼────────────────────┤
│ Size                            │ 241B               │
├─────────────────────────────────┼────────────────────┤
│ Data URI Size                   │ 0                  │
├─────────────────────────────────┼────────────────────┤
│ Gzipped Size                    │ 158B               │
├─────────────────────────────────┼────────────────────┤
│ Rules                           │ 7                  │
├─────────────────────────────────┼────────────────────┤
│ Selectors                       │ 12                 │
├─────────────────────────────────┼────────────────────┤
│ Simplicity                      │ 58.3%              │
├─────────────────────────────────┼────────────────────┤
│ Average of Identifier           │ 1.25               │
├─────────────────────────────────┼────────────────────┤
│ Most Identifier                 │ 3                  │
├─────────────────────────────────┼────────────────────┤
│ Most Identifier Selector        │ .foo .bar .baz     │
├─────────────────────────────────┼────────────────────┤
│ Average of Cohesion             │ 1.4285714285714286 │
├─────────────────────────────────┼────────────────────┤
│ Lowest Cohesion                 │ 2                  │
├─────────────────────────────────┼────────────────────┤
│ Lowest Cohesion Selector        │ .foo               │
├─────────────────────────────────┼────────────────────┤
│ Total Unique Font Sizes         │ 2                  │
├─────────────────────────────────┼────────────────────┤
│ Unique Font Sizes               │ 12px               │
│                                 │ 16px               │
├─────────────────────────────────┼────────────────────┤
│ Total Unique Font Families      │ 0                  │
├─────────────────────────────────┼────────────────────┤
│ Unique Font Families            │ N/A                │
├─────────────────────────────────┼────────────────────┤
│ Total Unique Colors             │ 3                  │
├─────────────────────────────────┼────────────────────┤
│ Unique Colors                   │ #333333            │
│                                 │ #CCCCCC            │
│                                 │ RED                │
├─────────────────────────────────┼────────────────────┤
│ ID Selectors                    │ 1                  │
├─────────────────────────────────┼────────────────────┤
│ Universal Selectors             │ 1                  │
├─────────────────────────────────┼────────────────────┤
│ Unqualified Attribute Selectors │ 1                  │
├─────────────────────────────────┼────────────────────┤
│ JavaScript Specific Selectors   │ 0                  │
├─────────────────────────────────┼────────────────────┤
│ Important Keywords              │ 1                  │
├─────────────────────────────────┼────────────────────┤
│ Float Properties                │ 1                  │
├─────────────────────────────────┼────────────────────┤
│ Properties Count                │ color: 4           │
│                                 │ font-size: 3       │
│                                 │ margin: 2          │
│                                 │ float: 1           │
├─────────────────────────────────┼────────────────────┤
│ Media Queries                   │ 0                  │
└─────────────────────────────────┴────────────────────┘

Specified css file will be analyzed.

# Providing multiple input is also supported.
$ stylestats foo.css bar.css baz.css

CSS files in specified directory will be analyzed.

$ stylestats path/to/dir

Glob input is supported (quotes are required).

$ stylestats 'path/**/*.css'

You can specify a remote CSS file.

$ stylestats http://t32k.me/wisteria/css/wisteria.css

If you specify an HTML page, StyleStats will analyze stylesheets and style elements.

$ stylestats http://t32k.me/

--format option outputs JSON, HTML, Markdown and CSV.

$ stylestats foo.css -f <json|html|md|csv>

If you have gist installed, you can upload StyleStats data to GitHub Gist with a one-liner command.

$ stylestats http://t32k.me/ -f md > stats.md && gist stats.md
https://gist.github.com/9725673

Other tools

• Online tool
• Gulp module by @1000ch
• Grunt module by @tvooo

Metrics

Simplicity

The Simplicity is measured as Rules divided by Selectors.

Average of Identifier

The Average of Identifier is measured as Total Identifiers divided by Selectors.

Average of Cohesion

The Average of Cohesion is measured as Total declarations divided by Rules.

Lowest Cohesion

The Lowest Cohesion metric is the number of selector declarations.

See also:

• SOLID CSS | Blog | Miller Medeiros

Unqualified Attribute Selectors

The Unqualified Attribute Selectors metrics is the number of unqualified attribute selectors.

The following patterns will be counted:

[type=text] {
    color: red;
}

.selected [type=text] {
    color: red;
}

The following patterns are considered to be okay and will not be counted:

/* unqualified attribute selector is not key */
.selected [type=text] a {
    color: red;
}

See also:

• Disallow unqualified attribute selectors · stubbornella/csslint Wiki

JavaScript Specific Selectors

The JavaScript Specific Selectors metrics is the number of JavaScript-specific selectors, such as js-*. The selectors are only for JavaScript hooks; you should not to hang any presentation off them.

See also:

• About HTML semantics and front-end architecture – Nicolas Gallagher

User Specified Selectors

The User Specified Selectors metrics is the number of user-specified selectors. Default is false. For instance, you can count the number of components if you specify "\\.component\\-" using reqular expression in .stylestatsrc .

Properties Count

The Properties Count is the number of property declarations. The default is to display the top 10 properties.

Configuration

You can configure StyleStats.

CLI:

$ stylestats -c path/to/.stylestatsrc

API:

var StyleStats = require('stylestats');
var stats = new StyleStats('path/to/stylesheet.css', 'path/to/.stylestatsrc');

Default configuration is here.

Here is an example JSON to enable display gzipped size:

{
  "gzippedSize": false
}

gzippedSize attribute is true by default.

CLI Reference

Help:

$ stylestats --help

  Usage: stylestats [options] <file ...>

  Options:

    -h, --help             output usage information
    -V, --version          output the version number
    -c, --config <path>    set configurations
    -f, --format <format>  set the output format <json|html|md|csv>
    -t, --template <path>  set the template path for output formant
    -s, --specs <path>     run test with your test specs file
    -n, --number           show only numeral metrics
    -m, --mobile           set the mobile user agent

Example:

$ stylestats path/to/stylesheet.css -c path/to/.stylestatsrc
 StyleStats!
┌────────────────────────────┬────────┐
│ Style Sheets               │ 1      │
├────────────────────────────┼────────┤
│ Size                       │ 19.0KB │
├────────────────────────────┼────────┤
│ Gzipped Size               │ 3.7KB  │
├────────────────────────────┼────────┤
│ Total Unique Font Families │ 3      │
└────────────────────────────┴────────┘

Integration

• Plot your data with Jenkins
• Plot your data with moniteur
• Plot your data with Google Analytics

API Reference

new StyleStats(stylesheet, config)

1. stylesheet Required String|Array Stylesheet file path or its array.
2. config Optional String|Object Configuration JSON file path or object.

StyleStats.parse(fn)

var StyleStats = require('stylestats');
var stats = new StyleStats('path/to/stylesheet.css');

stats.parse(function (error, result) {
  console.log(JSON.stringify(result, null, 2));
});

Example

CSS example:

* { float: left; }
body { color: #333; }
h1, h2, h3, h4, h5, h6 { margin: 0; }
a[src] { color: red !important; }
.foo { color: #ccc; font-size: 12px; }
.foo .bar .baz { color: #ccc; font-size: 12px; }
#bar { margin: 10px; font-size: 16px; }

Statistics tree of above css:

{
  "published": "2014-06-14T10:10:40.825Z",
  "paths": [ "test/fixture/example.css" ],
  "stylesheets": 1,
  "size": 240,
  "dataUriSize": 0,
  "gzippedSize": 158,
  "rules": 7,
  "selectors": 12,
  "simplicity": 0.5833333333333334,
  "averageOfIdentifier": 1.25,
  "mostIdentifier": 3,
  "mostIdentifierSelector": ".foo .bar .baz",
  "averageOfCohesion": 1.4285714285714286,
  "lowestCohesion": 2,
  "lowestCohesionSelector": [ ".foo" ],
  "totalUniqueFontSizes": 2,
  "uniqueFontSizes": [ "12px", "16px" ],
  "totalUniqueFontFamilies": 0,
  "uniqueFontFamilies": [],
  "totalUniqueColors": 3,
  "uniqueColors": [ "#333333", "#CCCCCC", "RED" ],
  "idSelectors": 1,
  "universalSelectors": 1,
  "unqualifiedAttributeSelectors": 1,
  "javascriptSpecificSelectors": 0,
  "importantKeywords": 1,
  "floatProperties": 1,
  "mediaQueries": 0,
  "propertiesCount": [
    { "property": "color", "count": 4 },
    { "property": "font-size", "count": 3 },
    { "property": "margin", "count": 2 },
    { "property": "float", "count": 1 }
  ]
}

License

Code is released under the MIT license.