53 lines
1.4 KiB
Markdown
53 lines
1.4 KiB
Markdown
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# import/no-mutable-exports
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Forbids the use of mutable exports with `var` or `let`.
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## Rule Details
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Valid:
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```js
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export const count = 1
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export function getCount() {}
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export class Counter {}
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```
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...whereas here exports will be reported:
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```js
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export let count = 2
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export var count = 3
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let count = 4
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export { count } // reported here
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```
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## Functions/Classes
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Note that exported function/class declaration identifiers may be reassigned,
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but are not flagged by this rule at this time. They may be in the future, if a
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reassignment is detected, i.e.
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```js
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// possible future behavior!
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export class Counter {} // reported here: exported class is reassigned on line [x].
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Counter = KitchenSink // not reported here unless you enable no-class-assign
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// this pre-declaration reassignment is valid on account of function hoisting
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getCount = function getDuke() {} // not reported here without no-func-assign
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export function getCount() {} // reported here: exported function is reassigned on line [x].
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```
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To prevent general reassignment of these identifiers, exported or not, you may
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want to enable the following core ESLint rules:
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- [no-func-assign]
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- [no-class-assign]
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[no-func-assign]: https://eslint.org/docs/rules/no-func-assign
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[no-class-assign]: https://eslint.org/docs/rules/no-class-assign
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## When Not To Use It
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If your environment correctly implements mutable export bindings.
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