PostCSS Parser Tests

This project contains base tests for every PostCSS CSS parser, including:

• 24 CSS files to test extreme cases of the CSS specification.
• Integration tests by popular website styles to test CSS from the wild.

These tests are useful for any CSS parser, not just parsers within the PostCSS ecosystem.

Cases

You can iterate through all test cases using the cases.each method:

const cases = require('postcss-parser-tests')

cases.each((name, css, ideal) => {
  it('parses ' + name, () => {
    const root = parse(css, { from: name })
    const json = cases.jsonify(root)
    expect(json).toEquql(ideal)
  })
})

This returns the case name, CSS string, and PostCSS AST JSON.

If you create a non-PostCSS parser, just compare if the input CSS is equal to the output CSS after parsing.

You can also get the path to some specific test cases using the cases.path(name) method.

Integration

Integration tests are packed into a Gulp task:

const cases = require('postcss-parser-tests')

cases.real(css => {
  return parser(css).toResult({ map: { annotation: false } })
})

Your callback must parse CSS and stringify it back. The plugin will then compare the input and output CSS.

You can add extra sites using an optional third argument:

cases.real(css => {
  return parser(css).toResult({ map: { annotation: false } })
}, [
  'http://browserhacks.com/'
])