The critical semantics are resilient to browser flakiness, so we don't
need this feature test.
Also added comments explaining how invokeGuardedCallback dev works.
* Support throwing null
In JavaScript, you can throw values of any type, not just errors. That
includes null. We currently rely on null checks to determine if a user-
provided function has thrown. This refactors our error handling code to
keep track of an explicit boolean flag instead.
* Add DOM fixture test case for break on exception behavior
* preventDefault error events during feature test
We call invokeGuardedCallbackDev at startup as part of a feature test.
But we don't want those errors to log to the console.
* Add throwing null test case
* Use ReactFeatureFlags instead of ReactDOMFeatureFlags
React ART uses this, too.
* Non-errors in error logger
If a non-error is thrown, we'll coerce the value to a string and use
that as the message.
* Disable Fiber specific test run in CI
This disables the comparison against previously recorded test. Instead,
we'll rely on jest failures to fail tests.
* Extract jest config into two separate projects for Fiber and Stack
Allows us to run both in the same jest run. The setupMocks file is forked into
specific environment configuration for each project. This replaces the
environment variable.
I used copy pasta here to make it clear. We can abstract this later. It's clear
to me that simply extracting shared stuff is not the best way to abstract this.
setupMocks for example didn't need all the code in both branches.
I think that some of the stuff that is shared such as error message extracting
etc. should probably be lifted out into a stand-alone jest project instead of
being shared.
* Fix class equivalence test
There's a behavior change when projects are used which makes
setupTestFrameworkScriptFile not override the normal config.
This test should probably just move to a separate CI script or something
less hacky.
* Only run Fiber tests with scripts/fiber/record-tests
