The `start` convention is a CRA convention but nobody else of the modern
frameworks / tools use this convention for a file watcher and dev mode.
Instead the common convention is `dev`. Instead `start` is for running a
production build that's already been built.
---------
Co-authored-by: Sebastian Silbermann <silbermann.sebastian@gmail.com>
It's confusing to new contributors, and me, that you're supposed to use
`yarn build-combined` for almost everything but not fixtures.
We should use only one build command for everything.
Updated fixtures to use the folder convention of build-combined.
* Don't call idle callback unless there's time remaining
* Expiration fixture
Fixture that demonstrates how async work expires after a certain interval.
The fixture clogs the main thread with animation work, so it only works if the
`timeout` option is provided to `requestIdleCallback`.
* Pass timeout option to requestIdleCallback
Forces `requestIdleCallback` to fire if too much time has elapsed, even if the
main thread is busy. Required to make expiration times work properly. Otherwise,
async work can expire, but React never has a chance to flush it because the
browser never calls into React.