       calls.should.eql 'ab'
 
     it 'parses, convert and stringify CSS', ->
-      a = (css) -> css.should.be.an.instanceof(Root)
+      a = (css) -> css.should.be.an.instanceof(postcss.Root)
       postcss(a).process('a {}').css.should.have.type('string')
 
     it 'adds map field only on request', ->


  describe 'process()', ->

    it 'returns Result object', ->
      result = postcss().process('a{}')
      result.should.be.an.instanceOf(Result)

SourceMap = require('source-map')
postcss   = require('../lib/postcss')
Result    = require('../lib/result')

describe 'postcss.Root', ->

  it 'allows to build own CSS', ->
    root = new postcss.Root()
    rule = new postcss.Rule(selector: 'a')
    rule.append( new postcss.Declaration(prop: 'color', value: 'black') )
    root.append( rule )

    root.toString().should.eql 'a {color: black}'

describe 'postcss()', ->

