Minify dead code elimination

Inlines bindings when possible. Tries to evaluate expressions and prunes unreachable as a result

Example

In

function foo() {var x = 1;}
function bar() { var x = f(); }
function baz() {
  var x = 1;
  console.log(x);
  function unused() {
    return 5;
  }
}

Out

function foo() {}
function bar() { f(); }
function baz() {
  console.log(1);
}

Installation

npm install babel-plugin-minify-dead-code-elimination

Usage

.babelrc

// without options
{
  "plugins": ["minify-dead-code-elimination"]
}

// with options
{
  "plugins": ["minify-dead-code-elimination", { "optimizeRawSize": true }]
}

Via CLI

babel --plugins minify-dead-code-elimination script.js

Via Node API

require("babel-core").transform("code", {
  plugins: ["minify-dead-code-elimination"]
});

Options

  • keepFnName - prevent plugin from removing function name. Useful for code depending on fn.name
  • keepFnArgs - prevent plugin from removing function args. Useful for code depending on fn.length
  • keepClassName - prevent plugin from removing class name. Useful for code depending on cls.name
  • tdz - Account for TDZ (Temporal Dead Zone)