mirror of
https://github.com/S2-/minifyfromhtml.git
synced 2025-08-03 20:30:04 +02:00
64 lines
957 B
Markdown
64 lines
957 B
Markdown
# babel-plugin-transform-remove-undefined
|
|
|
|
For variable assignments, this removes rvals that evaluate to `undefined`
|
|
(`var`s in functions only).
|
|
For functions, this removes return arguments that evaluate to `undefined`.
|
|
|
|
## Example
|
|
|
|
**In**
|
|
|
|
```javascript
|
|
let a = void 0;
|
|
function foo() {
|
|
var b = undefined;
|
|
return undefined;
|
|
}
|
|
```
|
|
|
|
**Out**
|
|
|
|
```javascript
|
|
let a;
|
|
function foo() {
|
|
var b;
|
|
return;
|
|
}
|
|
```
|
|
|
|
## Installation
|
|
|
|
```sh
|
|
npm install babel-plugin-transform-remove-undefined
|
|
```
|
|
|
|
## Usage
|
|
|
|
### Via `.babelrc` (Recommended)
|
|
|
|
**.babelrc**
|
|
|
|
```json
|
|
{
|
|
"plugins": ["babel-plugin-transform-remove-undefined"]
|
|
}
|
|
```
|
|
|
|
### Via CLI
|
|
|
|
```sh
|
|
babel --plugins babel-plugin-transform-remove-undefined script.js
|
|
```
|
|
|
|
### Via Node API
|
|
|
|
```javascript
|
|
require("@babel/core").transform("code", {
|
|
plugins: ["babel-plugin-transform-remove-undefined"]
|
|
});
|
|
```
|
|
|
|
## Options
|
|
|
|
+ `tdz` - Detect usages before declaration/initialization in let/const(throws) and var(void 0)
|