Unit test for fluent-react withLocalization fails inconsistently

[flut1]

I noticed that my pull request #378 was failing in Travis on the following test:

getString with access to the l10n context, with message changes

Upon further investigation, it seems like this also fails on the master branch, but not consistently. If I run all tests for fluent-react, they seem to sometimes succeed, and if I run this test in isolation it seems to always succeed.

I can think of 2 possible reasons:

• The tests are somehow affecting each other. The test is using the full rendering API from Enzyme. Their docs say that tests may affect each other.
• The test contains a race condition. The line l10n.setBundles([newBundle]); causes a force-update in WithLocalization, but maybe React doesn't flush these changes synchronously.

[flut1]

My suggestion would be to add wrapper.update() before the assertion here:

fluent.js/fluent-react/test/with_localization_test.js

Line 112 in ab37e18

This seems to fix it. Is it ok to force-update the component or should the test also assert that WithLocalization updates by itself?

A similar test in localized_change_test.js seems to already have this wrapper.update() statement before the last assertion:

fluent.js/fluent-react/test/localized_change_test.js

Line 35 in ab37e18

wrapper.update();

[stasm]

Thanks for the investigation, @flut1 :) I opened #384 to add wrapper.update() as you suggest. This should be sufficient for the time being. As you note, wrapper.update() is already used in other tests to serve the similar purpose.

The tests will need to be reviewed anyways when I start working on #182, which I hope is soon.