[electron] UnhandledPromiseRejec

$ vue-cli-service test:unit
 WEBPACK  Compiling...



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 DONE  Compiled successfully in 3044ms


 WEBPACK  Compiled successfully in 3044ms

 MOCHA  Testing...



  Application launch

(node:1112) UnhandledPromiseRejectionWarning: Error: ChromeDriver did not start within 5000ms
    at /Users/kerwin/Program/vue/tddvue/node_modules/spectron/lib/chrome-driver.js:63:25
    at Request._callback (/Users/kerwin/Program/vue/tddvue/node_modules/spectron/lib/chrome-driver.js:121:23)
    at self.callback (/Users/kerwin/Program/vue/tddvue/node_modules/request/request.js:185:22)
    at Request.emit (events.js:198:13)
    at Request.EventEmitter.emit (domain.js:448:20)
    at Request.onRequestError (/Users/kerwin/Program/vue/tddvue/node_modules/request/request.js:881:8)
    at ClientRequest.emit (events.js:198:13)
    at ClientRequest.EventEmitter.emit (domain.js:448:20)
    at Socket.socketErrorListener (_http_client.js:392:9)
    at Socket.emit (events.js:198:13)
    at Socket.EventEmitter.emit (domain.js:448:20)
    at emitErrorNT (internal/streams/destroy.js:91:8)
    at emitErrorAndCloseNT (internal/streams/destroy.js:59:3)
    at process._tickCallback (internal/process/next_tick.js:63:19)

(node:1112) UnhandledPromiseRejectionWarning: Unhandled promise rejection. This error originated either by throwing inside of an async function without a catch block, or by rejecting a promise which was not handled with .catch(). (rejection id: 1)
(node:1112) [DEP0018] DeprecationWarning: Unhandled promise rejections are deprecated. In the future, promise rejections that are not handled will terminate the Node.js process with a non-zero exit code.

    1) "before each" hook for "opens a window"

 ERROR  mochapack exited with code 1.


  HelloWorld.vue
    ✓ renders props.msg when passed


  1 passing (30s)
  1 failing

  1) Application launch
       "before each" hook for "opens a window":
     Error: Timeout of 30000ms exceeded. For async tests and hooks, ensure "done()" is called; if returning a Promise, ensure it resolves. (/Users/kerwin/Program/vue/tddvue/dist/js/main.js)
  



 MOCHA  Tests completed with 1 failure(s)


Total task duration: 39.28s

解决方法：

$ npm install --save-dev spectron