The primary goal here was to upgrade Ember to the latest LTS version (3.24) and as many of the other dependencies as necessary to get the app to build. Here is a brief overview of the changes and things to be aware of.

Linting

Some new lint rules were added which led to cleaning up all of the new and existing js and hbs lint errors. Since some rules are Octane focused, individual rules have either been globally ignored until we can fully glimmerize everything or ignored/configured to warn on a per file basis. The .eslintrc.js and .template-lintrc.js contain all the rule overrides. We should work towards fully adopting the recommended lint rules over time.

While template linting was available in the project prior to the upgrade it was not being utilized. Part of the issue (for me at least) was that the Ember Language Server VSCode extension was not working with ember-template-lint. It may no longer be maintained since there hasn't been an update since May 2020 and perhaps that is why it is not working in the latest VSCode with the newest version of ember-template-lint.

It is highly recommended to use the Unstable Ember Language Server extension which is a fork that is actively maintained and works with ember-template-lint in the Vault project. Since some folks may not prefer live linting in the editor I added the lint:hbs:quiet task to the test run. Both js and hbs linting must find no errors before the Ember tests will run. Note that the lint tasks that contain :quiet will not fail if they contain warnings. We should strive to resolve all warnings over time and eventually flip them back to error.

Deprecations

ember-cli-deprecation-workflow was enabled to handle deprecation warnings. It's not always trivial to refactor to get around deprecations and they may also be reported from addons which may involve updating, or in the case of no longer maintained addons there may need to be a plan to migrate away from usage. With that in mind I created an initializer to filter out deprecation warnings that will remain until version 4.0.0. This gives us time to address any immediate issues and plan a path forward before our next major upgrade.

Test Failures

After touching many files fixing lint errors it was expected that there would be failing tests. I would like to briefly highlight some async issues that reoccur throughout the acceptance tests. It seems that after the upgrade the issue has increased and many acceptance tests that wait on an async action before asserting that a route transition has taken place fail intermittently.

await click('[data-test-save]');
assert.equal(currentURL(), '/some/route', 'route changes after save');

There is a new lint rule that errors when placing settled(); after a click citing that the click handler uses settled internally. To get around this for the time being and attempt to fix the flakiness I refactored any failures caught by CircleCI to use waitUntil:

await click('[data-test-save']);
assert.ok(
  await waitUntil(() => currentURL() === '/some/route'),
  'route changes after save'
);

We should attempt to address this issue globally and try and get to a point where we can reduce the usage of settled and waitUntil which will both clean up the readability of the tests and reduce intermittent failures.