safer-rewire v1.0.2

safer-rewire

This micro-lib provides a wrapper for rewire, exposing additional functions that ensure the mocked functionality is replaced rather than added in to the tested module

Motivation

Idea for this project arose when encountered this issue in rewire library. After opening discussion of it, out of curiosity whipped up this lib to experiment whether more safer rewiring could be easily achieved, by leveraging the functionality inside rewire library.

Usage

Module exports a wrapper function, that accepts actual rewire function as parameter, and returns an object which exposes following properties:

Example

const rewire = require('rewire')
const saferRewire = require('safer-rewire')(rewire)
const { rewiredModule, __replaceWith__ } = saferRewire('foo.js')

describe('foo', () => {
  describe('#hello SAFE', () => {
    let mocks
    const hello = rewiredModule.__get__('hello')
    beforeEach(() => {
      mocks = {
        bar: sinon.stub().returns('bar message') // `bar` is not defined anywhere in foo.js
      }
    });
    it('should throw error from missing definition', () => {
      return __replaceWith__({ ...mocks })(() => {
        expect(() => hello()).to.throw('bar is not a function')
      })
    });
  });
});