How to unit test a Node.js module that requires other modules and how to mock the global require function?

Question

This is a trivial example that illustrates the crux of my problem:

var innerLib = require(\'./path/to/innerLib\');

function underTest() {
    return innerLi         


        

Answer 1

I use mock-require. Make sure you define your mocks before you require the module to be tested.

Answer 2

You can use mockery library:

describe 'UnderTest', ->
  before ->
    mockery.enable( warnOnUnregistered: false )
    mockery.registerMock('./path/to/innerLib', { doComplexStuff: -> 'Complex result' })
    @underTest = require('./path/to/underTest')

  it 'should compute complex value', ->
    expect(@underTest()).to.eq 'Complex result'