describe "Babel transpiler support", -> describe 'when a .js file starts with /** @babel */;', -> it "transpiles it using babel", -> transpiled = require('./fixtures/babel/babel-comment.js') expect(transpiled(3)).toBe 4 describe "when a .js file starts with 'use babel';", -> it "transpiles it using babel", -> transpiled = require('./fixtures/babel/babel-single-quotes.js') expect(transpiled(3)).toBe 4 describe 'when a .js file starts with "use babel";', -> it "transpiles it using babel", -> transpiled = require('./fixtures/babel/babel-double-quotes.js') expect(transpiled(3)).toBe 4 describe "when a .js file does not start with 'use babel';", -> it "does not transpile it using babel", -> expect(-> require('./fixtures/babel/invalid.js')).toThrow()