|
|
|
|
# import/extensions - Ensure consistent use of file extension within the import path
|
|
|
|
|
|
|
|
|
|
Some file resolve algorithms allow you to omit the file extension within the import source path. For example the `node` resolver can resolve `./foo/bar` to the absolute path `/User/someone/foo/bar.js` because the `.js` extension is resolved automatically by default. Depending on the resolver you can configure more extensions to get resolved automatically.
|
|
|
|
|
|
|
|
|
|
In order to provide a consistent use of file extensions across your code base, this rule can enforce or disallow the use of certain file extensions.
|
|
|
|
|
|
|
|
|
|
## Rule Details
|
|
|
|
|
|
|
|
|
|
This rule either takes one string option, one object option, or a string and an object option. If it is the string `"never"` (the default value), then the rule forbids the use for any extension. If it is the string `"always"`, then the rule enforces the use of extensions for all import statements. If it is the string `"ignorePackages"`, then the rule enforces the use of extensions for all import statements except package imports.
|
|
|
|
|
|
|
|
|
|
```
|
|
|
|
|
"import/extensions": [<severity>, "never" | "always" | "ignorePackages"]
|
|
|
|
|
```
|
|
|
|
|
|
|
|
|
|
By providing an object you can configure each extension separately.
|
|
|
|
|
|
|
|
|
|
```
|
|
|
|
|
"import/extensions": [<severity>, {
|
|
|
|
|
<extension>: "never" | "always" | "ignorePackages"
|
|
|
|
|
}]
|
|
|
|
|
```
|
|
|
|
|
|
|
|
|
|
For example `{ "js": "always", "json": "never" }` would always enforce the use of the `.js` extension but never allow the use of the `.json` extension.
|
|
|
|
|
|
|
|
|
|
By providing both a string and an object, the string will set the default setting for all extensions, and the object can be used to set granular overrides for specific extensions.
|
|
|
|
|
|
|
|
|
|
```
|
|
|
|
|
"import/extensions": [
|
|
|
|
|
<severity>,
|
|
|
|
|
"never" | "always" | "ignorePackages",
|
|
|
|
|
{
|
|
|
|
|
<extension>: "never" | "always" | "ignorePackages"
|
|
|
|
|
}
|
|
|
|
|
]
|
|
|
|
|
```
|
|
|
|
|
|
|
|
|
|
For example, `["error", "never", { "svg": "always" }]` would require that all extensions are omitted, except for "svg".
|
|
|
|
|
|
|
|
|
|
`ignorePackages` can be set as a separate boolean option like this:
|
|
|
|
|
```
|
|
|
|
|
"import/extensions": [
|
|
|
|
|
<severity>,
|
|
|
|
|
"never" | "always" | "ignorePackages",
|
|
|
|
|
{
|
|
|
|
|
ignorePackages: true | false,
|
|
|
|
|
pattern: {
|
|
|
|
|
<extension>: "never" | "always" | "ignorePackages"
|
|
|
|
|
}
|
|
|
|
|
}
|
|
|
|
|
]
|
|
|
|
|
```
|
|
|
|
|
In that case, if you still want to specify extensions, you can do so inside the **pattern** property.
|
|
|
|
|
Default value of `ignorePackages` is `false`.
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
### Exception
|
|
|
|
|
|
|
|
|
|
When disallowing the use of certain extensions this rule makes an exception and allows the use of extension when the file would not be resolvable without extension.
|
|
|
|
|
|
|
|
|
|
For example, given the following folder structure:
|
|
|
|
|
|
|
|
|
|
```
|
|
|
|
|
├── foo
|
|
|
|
|
│ ├── bar.js
|
|
|
|
|
│ ├── bar.json
|
|
|
|
|
```
|
|
|
|
|
|
|
|
|
|
and this import statement:
|
|
|
|
|
|
|
|
|
|
```js
|
|
|
|
|
import bar from './foo/bar.json';
|
|
|
|
|
```
|
|
|
|
|
|
|
|
|
|
then the extension can’t be omitted because it would then resolve to `./foo/bar.js`.
|
|
|
|
|
|
|
|
|
|
### Examples
|
|
|
|
|
|
|
|
|
|
The following patterns are considered problems when configuration set to "never":
|
|
|
|
|
|
|
|
|
|
```js
|
|
|
|
|
import foo from './foo.js';
|
|
|
|
|
|
|
|
|
|
import bar from './bar.json';
|
|
|
|
|
|
|
|
|
|
import Component from './Component.jsx';
|
|
|
|
|
|
|
|
|
|
import express from 'express/index.js';
|
|
|
|
|
```
|
|
|
|
|
|
|
|
|
|
The following patterns are not considered problems when configuration set to "never":
|
|
|
|
|
|
|
|
|
|
```js
|
|
|
|
|
import foo from './foo';
|
|
|
|
|
|
|
|
|
|
import bar from './bar';
|
|
|
|
|
|
|
|
|
|
import Component from './Component';
|
|
|
|
|
|
|
|
|
|
import express from 'express/index';
|
|
|
|
|
|
|
|
|
|
import * as path from 'path';
|
|
|
|
|
```
|
|
|
|
|
|
|
|
|
|
The following patterns are considered problems when configuration set to "always":
|
|
|
|
|
|
|
|
|
|
```js
|
|
|
|
|
import foo from './foo';
|
|
|
|
|
|
|
|
|
|
import bar from './bar';
|
|
|
|
|
|
|
|
|
|
import Component from './Component';
|
|
|
|
|
|
|
|
|
|
import foo from '@/foo';
|
|
|
|
|
```
|
|
|
|
|
|
|
|
|
|
The following patterns are not considered problems when configuration set to "always":
|
|
|
|
|
|
|
|
|
|
```js
|
|
|
|
|
import foo from './foo.js';
|
|
|
|
|
|
|
|
|
|
import bar from './bar.json';
|
|
|
|
|
|
|
|
|
|
import Component from './Component.jsx';
|
|
|
|
|
|
|
|
|
|
import * as path from 'path';
|
|
|
|
|
|
|
|
|
|
import foo from '@/foo.js';
|
|
|
|
|
```
|
|
|
|
|
|
|
|
|
|
The following patterns are considered problems when configuration set to "ignorePackages":
|
|
|
|
|
|
|
|
|
|
```js
|
|
|
|
|
import foo from './foo';
|
|
|
|
|
|
|
|
|
|
import bar from './bar';
|
|
|
|
|
|
|
|
|
|
import Component from './Component';
|
|
|
|
|
|
|
|
|
|
```
|
|
|
|
|
|
|
|
|
|
The following patterns are not considered problems when configuration set to "ignorePackages":
|
|
|
|
|
|
|
|
|
|
```js
|
|
|
|
|
import foo from './foo.js';
|
|
|
|
|
|
|
|
|
|
import bar from './bar.json';
|
|
|
|
|
|
|
|
|
|
import Component from './Component.jsx';
|
|
|
|
|
|
|
|
|
|
import express from 'express';
|
|
|
|
|
|
|
|
|
|
import foo from '@/foo'
|
|
|
|
|
```
|
|
|
|
|
|
|
|
|
|
The following patterns are not considered problems when configuration set to `['error', 'always', {ignorePackages: true} ]`:
|
|
|
|
|
|
|
|
|
|
```js
|
|
|
|
|
import Component from './Component.jsx';
|
|
|
|
|
|
|
|
|
|
import baz from 'foo/baz.js';
|
|
|
|
|
|
|
|
|
|
import express from 'express';
|
|
|
|
|
|
|
|
|
|
import foo from '@/foo';
|
|
|
|
|
```
|
|
|
|
|
|
|
|
|
|
## When Not To Use It
|
|
|
|
|
|
|
|
|
|
If you are not concerned about a consistent usage of file extension.
|