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marco/.agents/skills/ember-best-practices/rules/bundle-direct-imports.md

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---
title: Avoid Importing Entire Addon Namespaces
impact: CRITICAL
impactDescription: 200-500ms import cost reduction
tags: bundle, imports, tree-shaking, performance
---
## Avoid Importing Entire Addon Namespaces
Import specific utilities and components directly rather than entire addon namespaces to enable better tree-shaking and reduce bundle size.
**Incorrect (imports entire namespace):**
```javascript
import { tracked } from '@glimmer/tracking';
import Component from '@glimmer/component';
import { action } from '@ember/object';
// OK - these are already optimized
// But avoid this pattern with utility libraries:
import * as lodash from 'lodash';
import * as moment from 'moment';
class My extends Component {
someMethod() {
return lodash.debounce(this.handler, 300);
}
}
```
**Correct (direct imports):**
```javascript
import { tracked } from '@glimmer/tracking';
import Component from '@glimmer/component';
import { action } from '@ember/object';
import debounce from 'lodash/debounce';
import dayjs from 'dayjs'; // moment alternative, smaller
class My extends Component {
someMethod() {
return debounce(this.handler, 300);
}
}
```
**Even better (use Ember utilities when available):**
```javascript
import { tracked } from '@glimmer/tracking';
import Component from '@glimmer/component';
import { action } from '@ember/object';
import { debounce } from '@ember/runloop';
class My extends Component {
someMethod() {
return debounce(this, this.handler, 300);
}
}
```
Direct imports and using built-in Ember utilities reduce bundle size by avoiding unused code.