Ace TravisCI unit tests fail (yet pass on MacOS, Windows and Linux)

[danielweck]

Latest Ace 1.2.0-beta.13:
#315

https://travis-ci.org/github/daisy/ace/jobs/684576632

TypeError: _fakeTimers(...).LegacyFakeTimers is not a constructor

[danielweck]

https://travis-ci.org/github/daisy/ace/jobs/684601865

Investigation shows that the LegacyFakeTimers class is in fact undefined

https://github.com/facebook/jest/blob/master/packages/jest-environment-node/src/index.ts
https://unpkg.com/browse/jest-environment-node@26.0.1/build/index.js

this.fakeTimers = new (_fakeTimers().LegacyFakeTimers)({
      config,
      global,
      moduleMocker: this.moduleMocker,
      timerConfig
    });

I note the typical TypeScript transpiled output for default exports and __esModule, but this works just fine in other Linux computers, so I fail to see what is specific to Travis here (same Node versions):

https://github.com/facebook/jest/blob/master/packages/jest-fake-timers/src/legacyFakeTimers.ts
https://unpkg.com/browse/@jest/fake-timers@26.0.1/build/legacyFakeTimers.js

Object.defineProperty(exports, '__esModule', {

https://github.com/facebook/jest/blob/master/packages/jest-fake-timers/src/index.ts
https://unpkg.com/browse/@jest/fake-timers@26.0.1/build/index.js

'use strict';

Object.defineProperty(exports, '__esModule', {
  value: true
});

Object.defineProperty(exports, 'LegacyFakeTimers', {
  enumerable: true,
  get: function () {
    return _legacyFakeTimers.default;
  }
});

var _legacyFakeTimers = _interopRequireDefault(require('./legacyFakeTimers'));


function _interopRequireDefault(obj) {
  return obj && obj.__esModule ? obj : {default: obj};
}

[danielweck]

Note that other modules work, such as this.moduleMocker = new (_jestMock().ModuleMocker)(global);:
https://unpkg.com/browse/jest-environment-node@26.0.1/build/index.js
=>
https://unpkg.com/browse/jest-mock@26.0.1/build/index.js

...so I am guessing the problem stems from the level of indirection:
https://unpkg.com/browse/@jest/fake-timers@26.0.1/build/index.js

[danielweck]

Fixed: https://travis-ci.org/github/daisy/ace/builds/684668999