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babel-plugin-transform-remove-undefined

For functions, this removes return arguments that evaluate to undefined.

Example

In

let a = void 0;
function foo() {
  var b = undefined;
  return undefined;
}

Out

let a;
function foo() {
  var b;
  return;
}

Installation

npm install babel-plugin-transform-remove-undefined --save-dev

Usage

With a configuration file (Recommended)

{
  "plugins": ["babel-plugin-transform-remove-undefined"]
}

Via CLI

babel --plugins babel-plugin-transform-remove-undefined script.js

Via Node API

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)

You can read more about configuring plugin options here

  • Example
  • Installation
  • Usage
    • With a configuration file (Recommended)
    • Via CLI
    • Via Node API
  • Options
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