107 lines
2.8 KiB
Markdown
107 lines
2.8 KiB
Markdown
# import/namespace
|
|
|
|
💼 This rule is enabled in the following configs: ❗ `errors`, ☑️ `recommended`.
|
|
|
|
<!-- end auto-generated rule header -->
|
|
|
|
Enforces names exist at the time they are dereferenced, when imported as a full namespace (i.e. `import * as foo from './foo'; foo.bar();` will report if `bar` is not exported by `./foo`.).
|
|
|
|
Will report at the import declaration if there are _no_ exported names found.
|
|
|
|
Also, will report for computed references (i.e. `foo["bar"]()`).
|
|
|
|
Reports on assignment to a member of an imported namespace.
|
|
|
|
Note: for packages, the plugin will find exported names
|
|
from [`jsnext:main`], if present in `package.json`.
|
|
Redux's npm module includes this key, and thereby is lintable, for example.
|
|
|
|
A module path that is [ignored] or not [unambiguously an ES module] will not be reported when imported.
|
|
|
|
[ignored]: ../README.md#importignore
|
|
[unambiguously an ES module]: https://github.com/bmeck/UnambiguousJavaScriptGrammar
|
|
|
|
## Rule Details
|
|
|
|
Currently, this rule does not check for possible
|
|
redefinition of the namespace in an intermediate scope. Adherence to the ESLint
|
|
`no-shadow` rule for namespaces will prevent this from being a problem.
|
|
|
|
For [ES7], reports if an exported namespace would be empty (no names exported from the referenced module.)
|
|
|
|
Given:
|
|
|
|
```js
|
|
// @module ./named-exports
|
|
export const a = 1
|
|
const b = 2
|
|
export { b }
|
|
|
|
const c = 3
|
|
export { c as d }
|
|
|
|
export class ExportedClass { }
|
|
|
|
// ES7
|
|
export * as deep from './deep'
|
|
```
|
|
|
|
and:
|
|
|
|
```js
|
|
// @module ./deep
|
|
export const e = "MC2"
|
|
```
|
|
|
|
See what is valid and reported:
|
|
|
|
```js
|
|
// @module ./foo
|
|
import * as names from './named-exports'
|
|
|
|
function great() {
|
|
return names.a + names.b // so great https://youtu.be/ei7mb8UxEl8
|
|
}
|
|
|
|
function notGreat() {
|
|
doSomethingWith(names.c) // Reported: 'c' not found in imported namespace 'names'.
|
|
|
|
const { a, b, c } = names // also reported, only for 'c'
|
|
}
|
|
|
|
// also tunnels through re-exported namespaces!
|
|
function deepTrouble() {
|
|
doSomethingWith(names.deep.e) // fine
|
|
doSomethingWith(names.deep.f) // Reported: 'f' not found in deeply imported namespace 'names.deep'.
|
|
}
|
|
|
|
```
|
|
|
|
### Options
|
|
|
|
#### `allowComputed`
|
|
|
|
Defaults to `false`. When false, will report the following:
|
|
|
|
```js
|
|
/*eslint import/namespace: [2, { allowComputed: false }]*/
|
|
import * as a from './a'
|
|
|
|
function f(x) {
|
|
return a[x] // Unable to validate computed reference to imported namespace 'a'.
|
|
}
|
|
```
|
|
|
|
When set to `true`, the above computed namespace member reference is allowed, but
|
|
still can't be statically analyzed any further.
|
|
|
|
## Further Reading
|
|
|
|
- Lee Byron's [ES7] export proposal
|
|
- [`import/ignore`] setting
|
|
- [`jsnext:main`](Rollup)
|
|
|
|
[ES7]: https://github.com/leebyron/ecmascript-more-export-from
|
|
[`import/ignore`]: ../../README.md#importignore
|
|
[`jsnext:main`]: https://github.com/rollup/rollup/wiki/jsnext:main
|