[random test failure] Drupal\Tests\settings_tray\FunctionalJavascript\SettingsTrayBlockFormTest::testEditModeEnableDisable

Problem/Motivation

Discovered at #3316274-74: Stabilize FunctionalJavascript testing AJAX: add ::assertExpectedAjaxRequest().

1) Drupal\Tests\settings_tray\FunctionalJavascript\SettingsTrayBlockFormTest::testEditModeEnableDisable
Failed asserting that false is true.

/var/www/html/vendor/phpunit/phpunit/src/Framework/Constraint/Constraint.php:121
/var/www/html/vendor/phpunit/phpunit/src/Framework/Constraint/Constraint.php:55
/var/www/html/core/modules/settings_tray/tests/src/FunctionalJavascript/SettingsTrayTestBase.php:117
/var/www/html/core/modules/settings_tray/tests/src/FunctionalJavascript/SettingsTrayBlockFormTest.php:244
/var/www/html/vendor/phpunit/phpunit/src/Framework/TestResult.php:726

This is happening in \Drupal\Tests\settings_tray\FunctionalJavascript\SettingsTrayTestBase::assertEditModeEnabled(), which is testing mouse over/hover triggering JS, it's unrelated to AJAX.

Steps to reproduce

Proposed resolution

• Use WaitTerminateTestTrait to allow unskipping ::testEditModeEnableDisable
• Use ::waitForElementVisible instead of usleep

See #21 and #23 for justification.

Remaining tasks

#3400318: Skip SettingsTrayBlockFormTest::testEditModeEnableDisable due to random fails

User interface changes

API changes

Data model changes

Release notes snippet