# ember/no-tracked-properties-from-args

💼 This rule is enabled in the ✅ `recommended` [config](https://github.com/ember-cli/eslint-plugin-ember#-configurations).

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Disallow creation of @tracked properties from args.

## Rule Details

This rule disallows the creation of @tracked properties with values from `this.args`. The @tracked property will not be updated when the args change, which is almost never what you want. Instead, use a getter to derive the desired state.
If you need to modify a specific arg, consider having the parent provide a way for the child component to update it. This avoids having two sources of truth that you will need to keep in sync.

## Examples

Examples of **incorrect** code for this rule:

```js
class Example {
  @tracked someValue = this.args.someValue;
}
```

Examples of **correct** code for this rule:

```js
class Example {
  get someValue() {
    return this.args.someValue;
  }
}
```

## References

- [Glimmer Components - args](https://guides.emberjs.com/release/upgrading/current-edition/glimmer-components/#toc_getting-used-to-glimmer-components) guide
- [tracked](https://guides.emberjs.com/release/in-depth-topics/autotracking-in-depth/) guide