use power-assert on .coffee test

grunt_slash_mochaTest.coffee

# have to remove compilers: 'coffee:coffee-script'
module.exports = 
    sample:
    options:
      reporter: 'spec'
      require: 'espower-coffee/guess'
      colors: true
      timeout: 10000
    src: [
      'test/power-assert.coffee'
      ]     

Gruntfile.coffee

module.exports = (grunt) ->
  require('time-grunt')(grunt)
  require('load-grunt-config')(grunt)

output

$ grunt mochaTest:sample
Running "mochaTest:sample" (mochaTest) task


  array
    #indexOf()
      1) should return index when the value is present


  0 passing (10ms)
  1 failing

  1) array #indexOf() should return index when the value is present:
     AssertionError: # /Users/pochi/Documents/development/(snip)/test/power-assert.coffee:15

assert(this.arr.indexOf(zero) === two)
            |   |       |     |   |   
            |   |       |     |   2   
            |   -1      0     false   
            [1,2,3]                   

[number] two
=> 2
[number] this.arr.indexOf(zero)
=> -1

package.json

{
  "private": true,
  "dependencies": {
    "coffee-script": "~1.7.1",
    "grunt-cli": "~0.1.13",
    "grunt": "~0.4.3",
    "grunt-mocha-test": "~0.7.0",
    "grunt-contrib-coffee": "^0.10.1",
    "time-grunt": "^0.3.1",
    "load-grunt-config": "^0.8.0"
  },
  "devDependencies": {
    "mocha": "~1.14.0",
    "should": "",
    "sinon": "",
    "espower-coffee": "^0.1.0"
  }
}

test_slash_power-assert.coffee

assert = require 'power-assert'

describe 'array', ->
  beforeEach ->
    @arr = [1,2,3]
  describe '#indexOf()', ->
    it 'should return index when the value is present', ->
      zero = 0
      two = 2
      assert(@arr.indexOf(zero) is two)