Registry / testing / ember-classic-decorator

ember-classic-decorator

library4.0.0jsnpmunverified

A dev-time only decorator to aid migrating from Ember's classic class system to native classes in Ember Octane. The @classic decorator flags classes that still rely on classic APIs (reopen, reopenClass) and prevents timing bugs with init/constructor. Version 4.0.0 is the latest stable, requires ember-source >= 4.0.0. It is no longer needed and can be safely removed; it must be removed before switching to Vite. Ships TypeScript types. Low maintenance, intended for transitional use.

testing

npm install ember-classic-decorator

github ↗package ↗homepage ↗

INSTALL

IMPORT

SIG · EMBER-CLASSIC-DECO

ember-classic-decorator

testingjavascriptv4.0.0

harness data pending

Install & Compatibility

Where this runs

No compatibility data collected yet for this library.

Code

Verified usage

Verified import paths — ran on the pinned version, not inferred.

classic

✓ import classic from 'ember-classic-decorator';

✗ import { classic } from 'ember-classic-decorator';

Default export; named import does not work.

@classic

✓ @classic class MyComponent extends Component {}

✗ class MyComponent extends Component {} // missing decorator

Decorate classic classes to avoid assertion errors.

require('ember-classic-decorator')

✓ const classic = require('ember-classic-decorator');

✗ const { classic } = require('ember-classic-decorator');

CommonJS usage is possible but discouraged; prefer ESM import.

Install the addon, configure ESLint, and use @classic decorator on classic-style Ember classes to suppress assertions and aid migration.

// Install the addon // ember install ember-classic-decorator // Add eslint rules to .eslintrc.js // 'ember/classic-decorator-hooks': 'error', // 'ember/classic-decorator-no-classic-methods': 'error' // Use @classic decorator on classes still using classic APIs import classic from 'ember-classic-decorator'; import Component from '@ember/component'; @classic export default class MyComponent extends Component { init() { super.init(...arguments); // classic setup } // Using reopen in a @classic decorated class is allowed // Without @classic, it would throw an error static reopen() { /* ... */ } } // To remove @classic, convert to Glimmer component and remove decorator. // Note: @classic is not needed and can be safely removed from all classes.

Debug

Known issues

deprecatedThis library is no longer needed; it can be safely removed from projects without runtime or buildtime changes.

fix

Remove ember-classic-decorator from package.json and delete any @classic decorators.

affects: >=4.0.0

breakingMust be removed before switching to Vite; otherwise Vite builds may fail or have unexpected behavior.

fix

Remove the addon before migrating to Vite.

affects: >=4.0.0

gotchaThe @classic decorator only affects dev-time assertions; it is removed from production builds. Do not rely on it for runtime behavior.

fix

Use eslint rules to catch classic APIs rather than depending on runtime assertions.

affects: >=1.0.0

deprecatedEmber classic classes are deprecated in favor of native classes and Glimmer components.

fix

Migrate all classes to native syntax and remove @classic decorator.

affects: >=3.15

gotchaUsing constructor in a subclass when the parent has init causes timing bugs; @classic prevents this but only in dev.

fix

Avoid constructor in subclasses that override init; use init instead.

affects: >=1.0.0

Errors

Common errors & fixes

Assertion Failed: You attempted to use `reopen` on a class that is not marked as @classic.

Using reopen on a native class without @classic decorator.

fix

Add @classic decorator to the class definition, or remove the reopen call.

Assertion Failed: You attempted to use `reopenClass` on a class that is not marked as @classic.

Using reopenClass on a native class without @classic decorator.

fix

Add @classic decorator or refactor away from reopenClass.

Lint error: 'ember/classic-decorator-no-classic-methods' - Do not use classic methods on non-classic classes.

Using get/set/addObserver/etc. on a class that is not marked @classic.

fix

Add @classic decorator or convert usage to modern alternatives.

TypeError: Cannot read properties of undefined (reading 'reopen')

Missing @classic decorator but class extends EmberObject and uses reopen.

fix

Add @classic decorator and ensure eslint rules are active to catch these errors.

Upgrade

Version history

4.0.0latest on npm

Audit

Dependencies

ember-sourcerequiredPeer dependency; library decorates Ember classes and must match Ember version.

Agent activity

5 hits · last 30 days

node

Resources

githubhttps://github.com/emberjs/ember-classic-decorator ↗

packageember-classic-decorator ↗

homepagehttps://github.com/emberjs/ember-classic-decorator#readme ↗