Expected Behavior of Error Propogation

[Austio]

Hey sorry for the multiple issues but saw this while driving out a test.

This may be more of a discussion, but what is the intended behavior of error propogation in vue-test-utils? I created an example below but what i'm seeing in production is a mounted function in throwing an error due to some bad assumptions and that causes a white screen. In my test when i reproduce by throwing an error in the mounted function I see the error in the console but I am not able to access it in vue-test-utils, i've tried numerous 'mocha' like ways to get the error to surface but was unable to.

Any thoughts on how to get access to thrown errors?

Here is a repo with reproduction.
https://github.com/Austio/vue-test-utils-mocha-webpack-example/pull/1/files

[Austio]

I think that the throw('error') should either be accessible on the wrapper or propagate up. See repo for above for the full example.

mounted() {
  console.error('throwing an error');
  throw('Error');
}

[Austio]

found a way to test the error, does not seem ideal but would work

describe('when it errors', function() {
    let errorConsole;
    beforeEach(() => {
      errorConsole = sinon.stub(console, 'error');
    });

    afterEach(() => {
      errorConsole.restore();
    });

    it('does not error when the header is initialized with null', function() {
      mount(LoggedIn, {
        localVue,
        attachToDocument: true,
        store,
      });

      expect(errorConsole.called, `Console Error: ${errorConsole.args[0]}`).not
        .to.be.true;
    });``

[Austio]

Had an additional thought on this. Could we take advantage of the errorHandler?

function globalHandleError (err, vm, info) {
  if (config.errorHandler) {
    try {
      return config.errorHandler.call(null, err, vm, info)
    } catch (e) {
      logError(e, null, 'config.errorHandler')
    }
  }
  logError(err, vm, info)
}

[eddyerburgh]

Hi @Austio.

You're right, thrown errors should make a test fail. Are you able to make a PR to improve error propagation?

[Austio]

@eddyerburgh #154 Proof of concept for idea to handle. Please let me know what you think and will finish out if this is good direction to go.

[eddyerburgh]

Looks perfect Austio, I've left some feedback on style issues, ready to merge when they're fixed