proxyquire-2/examples/sinon/foo-tests.js

Proxies import/require in order to allow overriding dependencies during testing.

"use strict";
/*jshint asi:true*/
/*global describe before beforeEach after afterEach it */

/*
 * These examples demonstrate how to use proxyquire with Sinon.JS (<http://sinonjs.org/>).
 * Run these tests with mocha (<http://visionmedia.github.com/mocha/>).
 * e.g., mocha foo-tests.js
 */

var proxyquire =  require('../..')
  , sinon      =  require('sinon')
  , assert     =  require('assert')
  , fs         =  require('fs')
  , path       =  require('path')
  , foo
  ;

// Stubbing return values
describe('when path.extname(file) returns ".markdown"', function () {
  var extnameStub
    , file = 'somefile';

  before(function () {
    extnameStub = sinon.stub(path, 'extname');
    foo = proxyquire('./foo', { path: { extname: extnameStub } } );

    extnameStub.withArgs(file).returns('.markdown');
  })

  after(function () {
    path.extname.restore();
  });
  
  it('extnameAllCaps returns ".MARKDOWN"', function () {
    assert.equal(foo.extnameAllCaps(file), '.MARKDOWN');
  })
})

// Stubbing callbacks
describe('when fs.readdir calls back with ["file1", "file2"]', function () {
  var readdirStub;

  before(function () {
    readdirStub = sinon.stub(fs, 'readdir');
    foo = proxyquire('./foo', { fs: { readdir: readdirStub } } );

    readdirStub.withArgs('../simple').yields(null, [ 'file1', 'file2' ]);
  })  

  after(function () {
    fs.readdir.restore();
  });

  it('filesAllCaps calls back with ["FILE1", "FILE2"]', function (done) {
    foo.filesAllCaps('../simple', function (err, files) {
      assert.equal(err, null);
      assert.equal(files[0], 'FILE1');
      assert.equal(files[1], 'FILE2');
      done();
    });
  })
})

describe('when fs.readdir returns an error', function () {
  var readdirError
    , readdirStub;

  before(function () {
    readdirStub = sinon.stub(fs, 'readdir');
    foo = proxyquire('./foo', { fs: { readdir: readdirStub } } );

    readdirError = new Error('some error');
    readdirStub.withArgs('../simple').yields(readdirError, null);
  })  

  after(function () {
    fs.readdir.restore();
  });

  it('filesAllCaps calls back with that error', function (done) {
    foo.filesAllCaps('../simple', function (err, files) {
      assert.equal(err, readdirError);
      assert.equal(files, null);
      done();
    });
  })
})

// Spying
describe('when calling filesAllCaps with "../simple"', function () {
  
  var readdirSpy;

  before(function () {
    readdirSpy = sinon.spy(fs, 'readdir');
    foo = proxyquire('./foo', { fs: { readdir: readdirSpy } } );
  })

  after(function () {
    fs.readdir.restore();
  });

  it('calls fs.readdir with "../simple"', function (done) {
    foo.filesAllCaps('../simple', function (err, files) {
      assert(fs.readdir.calledOnce);
      assert.equal(fs.readdir.getCall(0).args[0], '../simple');
      done();
    });
  })
})