60 lines
1.0 KiB
Markdown
60 lines
1.0 KiB
Markdown
|
# babel-plugin-check-es2015-constants
|
||
|
|
||
|
Validate ES2015 constants (prevents reassignment of const variables).
|
||
|
|
||
|
## Example
|
||
|
|
||
|
**In**
|
||
|
|
||
|
```js
|
||
|
const a = 1;
|
||
|
a = 2;
|
||
|
```
|
||
|
|
||
|
**Out**
|
||
|
|
||
|
```bash
|
||
|
repl: "a" is read-only
|
||
|
1 | const a = 1;
|
||
|
> 2 | a = 2;
|
||
|
| ^
|
||
|
```
|
||
|
|
||
|
[Try in REPL](http://babeljs.io/repl/#?babili=false&evaluate=true&lineWrap=false&presets=es2015&experimental=false&loose=false&spec=false&code=const%20a%20%3D%201%3B%0Aa%20%3D%202%3B&playground=true)
|
||
|
|
||
|
## Installation
|
||
|
|
||
|
```sh
|
||
|
npm install --save-dev babel-plugin-check-es2015-constants
|
||
|
```
|
||
|
|
||
|
## Usage
|
||
|
|
||
|
### Via `.babelrc` (Recommended)
|
||
|
|
||
|
**.babelrc**
|
||
|
|
||
|
```json
|
||
|
{
|
||
|
"plugins": ["check-es2015-constants"]
|
||
|
}
|
||
|
```
|
||
|
|
||
|
### Via CLI
|
||
|
|
||
|
```sh
|
||
|
babel --plugins check-es2015-constants script.js
|
||
|
```
|
||
|
|
||
|
### Via Node API
|
||
|
|
||
|
```javascript
|
||
|
require("babel-core").transform("code", {
|
||
|
plugins: ["check-es2015-constants"]
|
||
|
});
|
||
|
```
|
||
|
|
||
|
## Note
|
||
|
|
||
|
This check will only validate consts. If you need it to compile down to `var` then you must also install and enable [`transform-es2015-block-scoping`](http://babeljs.io/docs/plugins/transform-es2015-block-scoping/).
|