Summary:
Adds a new `npm run test-window` that will launch specs in a window so you
can use the debugger
The spec window wouldn't close because `onbeforeunload` was unnecessarily
preventing close. This circumvents this in spec mode.
Most significantly I discovered we can't use the synchronous timer for the
promise scheduler anymore. Suppose you do:
```
it('should error', async () => {
try {
await doSomething()
throw new Error("doSomething should have thrown!")
} catch (err) {
expect(err.message).toMatch(/my message/)
}
})
```
The way async/await is transpiled, when `doSomething` throws, the error
will propagate all the way back up to the uncaughtPromiseException handler
before the `catch` gets called and registered. The transpilation method
assumes that when the function gets executed it can synchrously advance
beyond the call before the `then` or `catch` resolve. When the promise
scheduler is synchronous this doesn't happen.
I chose to use `setTimeout` instead of `process.nextTick` or
`setImmediate` as the promise scheduler. `setTimeout` seems to work better
with Chrome's async function call stacks. `nextTick` and `setImmediate`,
being Node methods, skip Chrome's async watchers.
Test Plan:
I talked with Juan about these changes, in an upcoming diff he will be
testing these in the context of our broader test suite.
Reviewers: mark, khamidou, halla, spang, juan
Reviewed By: juan
Differential Revision: https://phab.nylas.com/D3779
