ember/no-tracked-built-ins

March 14, 2026 · View on GitHub

🔧 This rule is automatically fixable by the --fix CLI option.

Enforce usage of @ember/reactive/collections imports instead of tracked-built-ins.

Context

Per RFC #1068, the tracked collection utilities from the tracked-built-ins package are being moved into the framework as @ember/reactive/collections. The new API also changes from class constructors (new TrackedArray(...)) to factory functions (trackedArray(...)).

Rule Details

This rule detects imports from tracked-built-ins and provides an autofix to convert them to @ember/reactive/collections with the new function-based API.

The following mappings are applied:

Old (tracked-built-ins)New (@ember/reactive/collections)
TrackedArraytrackedArray
TrackedObjecttrackedObject
TrackedMaptrackedMap
TrackedSettrackedSet
TrackedWeakMaptrackedWeakMap
TrackedWeakSettrackedWeakSet

Additionally, new expressions using these imports are automatically converted to direct function calls.

Examples

Examples of incorrect code for this rule:

import { TrackedArray } from 'tracked-built-ins';

const arr = new TrackedArray([1, 2, 3]);

import { TrackedObject, TrackedMap } from 'tracked-built-ins';

const obj = new TrackedObject({ a: 1 });
const map = new TrackedMap();

Examples of correct code for this rule:

import { trackedArray } from '@ember/reactive/collections';

const arr = trackedArray([1, 2, 3]);

import { trackedObject, trackedMap } from '@ember/reactive/collections';

const obj = trackedObject({ a: 1 });
const map = trackedMap();

Migration

This rule provides automatic fixes via --fix. Running ESLint with the --fix flag will:

  1. Replace import { TrackedArray } from 'tracked-built-ins' with import { trackedArray } from '@ember/reactive/collections'
  2. Replace new TrackedArray(...) with trackedArray(...)

References