test(upgrade): clean up global state after test (#28181)
In ngUpgradeLite, when a downgraded component
[requests its downgraded module][1], the AngularJS injector is
[temporarily stored][2] with the intention of grabbing it
[once the module has been bootstrapped][3] (which also cleans up the
[temporary injector reference][4]).
In [some tests][5], bootstrapping a component might throw an error,
which causes the test to fail immediatelly and move on to the next
test. In slow browsers (e.g. on CI/Saucelabs), the (successful)
bootstrapping of another downgraded module might not have been
completed in time and thus the temporary injector reference not cleaned
up.
In such a case, if the following test (in our randomized test suite)
happens to rely on the temporary injector reference's being initially
unset (such as [this test][6]), it will fail. This might appear as a
flake on CI, because it depends on a race condition and specific order
of tests, so it usually goes away after a rerun.
This commit fixes it by ensuring the temporary injector reference is
manually cleaned up, when necessary.
Jira issue: FW-939
[1]: f983e99fb2/packages/upgrade/src/common/downgrade_component.ts (L120)
[2]: f983e99fb2/packages/upgrade/src/static/downgrade_module.ts (L165)
[3]: f983e99fb2/packages/upgrade/src/static/downgrade_module.ts (L169)
[4]: f983e99fb2/packages/upgrade/src/static/angular1_providers.ts (L25)
[5]: f983e99fb2/packages/upgrade/test/static/integration/downgrade_module_spec.ts (L1331-L1381)
[6]: f983e99fb2/packages/upgrade/test/static/angular1_providers_spec.ts (L31-L45)
PR Close #28181
3b7a571cc5