Reports when named exports are not grouped together in a single export declaration or when multiple assignments to CommonJS module.exports or exports object are present in a single file.
Rationale: An export declaration or module.exports assignment can appear anywhere in the code. By requiring a single export declaration all your exports will remain at one place, making it easier to see what exports a module provides.
This rule warns whenever a single file contains multiple named export declarations or multiple assignments to module.exports (or exports).
js
// A single named export declaration -> ok
export const valid = true
```js const first = true const second = true
// A single named export declaration -> ok export { first, second, } ```
js
// Aggregating exports -> ok
export { default as module1 } from 'module-1'
export { default as module2 } from 'module-2'
js
// A single exports assignment -> ok
module.exports = {
first: true,
second: true
}
```js const first = true const second = true
// A single exports assignment -> ok module.exports = { first, second, } ```
```js function test() {} test.property = true test.another = true
// A single exports assignment -> ok module.exports = test ```
```ts const first = true; type firstType = boolean
// A single named export declaration (type exports handled separately) -> ok export {first} export type {firstType} ```
js
// Multiple named export statements -> not ok!
export const first = true
export const second = true
js
// Aggregating exports from the same module -> not ok!
export { module1 } from 'module-1'
export { module2 } from 'module-1'
js
// Multiple exports assignments -> not ok!
exports.first = true
exports.second = true
js
// Multiple exports assignments -> not ok!
module.exports = {}
module.exports.first = true
js
// Multiple exports assignments -> not ok!
module.exports = () => {}
module.exports.first = true
module.exports.second = true
```ts type firstType = boolean type secondType = any
// Multiple named type export statements -> not ok! export type {firstType} export type {secondType} ```
If you do not mind having your exports spread across the file, you can safely turn this rule off.