Constnium/node_modules/eslint-plugin-import/docs/rules/no-unused-modules.md

108 lines
2.8 KiB
Markdown
Raw Normal View History

2022-06-23 02:27:43 +02:00
# import/no-unused-modules
Reports:
- modules without any exports
- individual exports not being statically `import`ed or `require`ed from other modules in the same project
- dynamic imports are supported if argument is a literal string
## Rule Details
### Usage
In order for this plugin to work, one of the options `missingExports` or `unusedExports` must be enabled (see "Options" section below). In the future, these options will be enabled by default (see https://github.com/import-js/eslint-plugin-import/issues/1324)
Example:
```
"rules: {
...otherRules,
"import/no-unused-modules": [1, {"unusedExports": true}]
}
```
### Options
This rule takes the following option:
- **`missingExports`**: if `true`, files without any exports are reported (defaults to `false`)
- **`unusedExports`**: if `true`, exports without any static usage within other modules are reported (defaults to `false`)
- `src`: an array with files/paths to be analyzed. It only applies to unused exports. Defaults to `process.cwd()`, if not provided
- `ignoreExports`: an array with files/paths for which unused exports will not be reported (e.g module entry points in a published package)
### Example for missing exports
#### The following will be reported
```js
const class MyClass { /*...*/ }
function makeClass() { return new MyClass(...arguments) }
```
#### The following will not be reported
```js
export default function () { /*...*/ }
```
```js
export const foo = function () { /*...*/ }
```
```js
export { foo, bar }
```
```js
export { foo as bar }
```
### Example for unused exports
given file-f:
```js
import { e } from 'file-a'
import { f } from 'file-b'
import * as fileC from 'file-c'
export { default, i0 } from 'file-d' // both will be reported
export const j = 99 // will be reported
```
and file-d:
```js
export const i0 = 9 // will not be reported
export const i1 = 9 // will be reported
export default () => {} // will not be reported
```
and file-c:
```js
export const h = 8 // will not be reported
export default () => {} // will be reported, as export * only considers named exports and ignores default exports
```
and file-b:
```js
import two, { b, c, doAnything } from 'file-a'
export const f = 6 // will not be reported
```
and file-a:
```js
const b = 2
const c = 3
const d = 4
export const a = 1 // will be reported
export { b, c } // will not be reported
export { d as e } // will not be reported
export function doAnything() {
// some code
} // will not be reported
export default 5 // will not be reported
```
#### Important Note
Exports from files listed as a main file (`main`, `browser`, or `bin` fields in `package.json`) will be ignored by default. This only applies if the `package.json` is not set to `private: true`
## When not to use
If you don't mind having unused files or dead code within your codebase, you can disable this rule