README.md

babel-preset-minify

Babel preset for all minify plugins.

• Install
• Usage
• Options

Install

npm install babel-preset-minify --save-dev

Usage

Via .babelrc (Recommended)

.babelrc

{
  "presets": ["minify"]
}

or pass in options -

{
  "presets": [["minify", {
    "mangle": {
      "exclude": ["MyCustomError"]
    },
    "unsafe": {
      "typeConstructors": false
    },
    "keepFnName": true
  }]]
}

Via CLI

babel script.js --presets minify

Via Node API

const babel = require("@babel/core");
const fs = require("fs");

const code = fs.readFileSync("./input.js").toString();

const minified = babel.transform(code, {
  presets: ["minify"]
});

Options

Two types of options:

1. 1-1 mapping with plugin
2. The same option passed to multiple plugins

1-1 mapping with plugin

• false - disable plugin
• true - enable plugin
• { ...pluginOpts } - enable plugin and pass pluginOpts to plugin

OptionName	Plugin	DefaultValue
booleans	transform-minify-booleans	true
builtIns	minify-builtins	true
consecutiveAdds	transform-inline-consecutive-adds	true
deadcode	minify-dead-code-elimination	true
evaluate	minify-constant-folding	true
flipComparisons	minify-flip-comparisons	true
guards	minify-guarded-expressions	true
infinity	minify-infinity	true
mangle	minify-mangle-names	true
memberExpressions	transform-member-expression-literals	true
mergeVars	transform-merge-sibling-variables	true
numericLiterals	minify-numeric-literals	true
propertyLiterals	transform-property-literals	true
regexpConstructors	transform-regexp-constructors	true
removeConsole	transform-remove-console	false
removeDebugger	transform-remove-debugger	false
removeUndefined	transform-remove-undefined	true
replace	minify-replace	true
simplify	minify-simplify	true
simplifyComparisons	transform-simplify-comparison-operators	true
typeConstructors	minify-type-constructors	true
undefinedToVoid	transform-undefined-to-void	true

The same option passed to multiple plugins

• When multiple plugins require the same option, it's easier to declare it in one place. These options are passed on to two or more plugins.

OptionName	Plugins
keepFnName	Passed to mangle & deadcode
keepClassName	Passed to mangle & deadcode
tdz	Passed to builtIns, evaluate, deadcode, removeUndefined

Examples

{
  "presets": [["minify", {
    "evaluate": false,
    "mangle": true
  }]]
}

{
  "presets": [["minify", {
    "mangle": {
      "exclude": ["ParserError", "NetworkError"]
    }
  }]]
}

{
  "presets": [["minify", {
    "keepFnName": true
  }]]
}
// is the same as
{
  "presets": [["minify", {
    "mangle": {
      "keepFnName": true
    },
    "deadcode": {
      "keepFnName": true
    }
  }]]
}