jest.TestFrameworkSetup.js

import fs from 'fs'
import os from 'os'
import path from 'path'

// module mocks ***************************************/
jest.mock('fs')
jest.mock('os')
/** * **************************************************/

// Useful function mocks ******************************/
function mockReadFile (DataObj) {
  const stringData = JSON.stringify(DataObj, 'utf8')
  fs.readFileSync.mockReturnValue(stringData)
}
function mockWriteFile (DataObj) {
  fs.writeFile.mockImplementation(() => { return DataObj })
}
const NOOP = () => {} // classical no operation function
/** * *************************************************/

// Pre-Mocked modules ********************************/
const mockHomeDir = path.join('C:', 'User', 'home')
const mockInstallDir = path.join('C:', 'Program Files (x86)', 'World of Warcraft', 'Interface', 'AddOns')

os.homedir.mockReturnValue(mockHomeDir)
// fs module - anything that can create things
fs.WriteStream.mockImplementation(NOOP)
fs.mkdir.mockImplementation(NOOP)
fs.mkdirSync.mockImplementation(NOOP)
fs.readdirSync.mockImplementation(NOOP)
fs.chmod.mockImplementation(NOOP)
fs.chmodSync.mockImplementation(NOOP)
fs.chown.mockImplementation(NOOP)
fs.chownSync.mockImplementation(NOOP)
fs.write.mockImplementation(NOOP)
fs.writeSync.mockImplementation(NOOP)
fs.writeFile.mockImplementation(NOOP)
fs.writeFileSync.mockImplementation(NOOP)
fs.copyFile.mockImplementation(NOOP)
fs.copyFileSync.mockImplementation(NOOP)
/** * ***********************************************/

// Testing globals *********************************/
global.mockReadFile = mockReadFile
global.mockWriteFile = mockWriteFile
global.NOOP = NOOP
global.mockHomeDir = mockHomeDir
global.mockInstallDir = mockInstallDir
/** * ***********************************************/