code: function (fn) {
      var origError = console.error
      var origExit = process.exit
      var origLog = console.log
  
      console.error = error = jest.fn()
      console.log = print = jest.fn()
      process.exit = exit = jest.fn()
  
      return execPromise(fn).then(
        function (value) {
          console.error = origError
          console.log = origLog
          process.exit = origExit
  
          return value
        },
        function (reason) {
          console.error = origError
          console.log = origLog
          process.exit = origExit
  
          throw reason
        }
      )
    }
docs: Helper which runs execPromise with spies.