52 lines
813 B
Markdown
52 lines
813 B
Markdown
# babel-plugin-transform-undefined-to-void
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Some JavaScript implementations allow undefined to be overwritten, this may lead to peculiar bugs that are extremely hard to track down.
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This plugin transforms `undefined` into `void 0` which returns undefined regardless of if it's been reassigned.
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## Example
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**In**
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```javascript
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foo === undefined;
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```
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**Out**
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```javascript
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foo === void 0;
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```
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## Installation
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```sh
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npm install babel-plugin-transform-undefined-to-void --save-dev
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```
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## Usage
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### Via `.babelrc` (Recommended)
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**.babelrc**
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```json
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{
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"plugins": ["transform-undefined-to-void"]
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}
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```
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### Via CLI
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```sh
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babel --plugins transform-undefined-to-void script.js
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```
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### Via Node API
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```javascript
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require("@babel/core").transform("code", {
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plugins: ["transform-undefined-to-void"]
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});
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```
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