[Tobzzy]

Summary

addon/-private/utils/observer.js picks between async and sync observer implementations with gte('3.13.0') from ember-compatibility-helpers. The oldest Ember version this addon is tested against is 3.28 (ember-source: ~3.28.0 in devDependencies, and ember-lts-3.28 is the oldest scenario in tests/dummy/config/ember-try.js). The addon doesn't declare an Ember peer range, so I'm inferring 3.28 as the floor from that. On any version it is tested against, the check is always true and the non-async branch is dead code.

If you'd like to keep compatibility with Ember < 3.13 for consumers, happy to close this.

This removes the dead branch and the ember-compatibility-helpers dependency, which was only used here:

• observer, addObserver and removeObserver are now exported directly (previously the async* implementations, selected via USE_ASYNC_OBSERVERS).
• ember-compatibility-helpers is dropped from dependencies and yarn.lock is updated. It is still pulled in transitively by another package, so only the direct range was removed.

Behaviour

No behaviour change. One detail worth calling out: removeObserver was previously exported as emberRemoveObserver ? asyncRemoveObserver : emberRemoveObserver. emberRemoveObserver is always defined, so that already resolved to asyncRemoveObserver, which is what is exported now.

Testing

• yarn install --frozen-lockfile, yarn lint and yarn test pass locally (231 passed, 7 skipped).
• The TableStickyPolyfill maxStickyProportion tests are intermittently flaky on the unmodified v6.0.0-12 tag as well, unrelated to this change.