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Minify constant folding

Tries to evaluate expressions and inline the result. For now only deals with numbers and strings

Example

In

"a" + "b"
2 * 3;
4 | 3;
"b" + a + "c" + "d" + g + z + "f" + "h" + "i"

[a, b, c].concat([d, e], f, g, [h]);
["a", "b", "c"].join();
["a", "b", "c"].join('@');
[1, 2, 3].length;
[1, 2, 3][1];
[1, 2, 3].shift();
[1, 2, 3].slice(0, 2);
[a, b, c].pop();
[a, b, c].reverse();
"a,b,c".split(",");
"abc"[0];
"abc".charAt();
"abc".charAt(1);
"abc".length;

Out

"ab";
6;
7;
"b" + a + "cd" + g + z + "fhi";

[a, b, c, d, e, f, g, h];
"a,b,c";
"a@b@c";
3;
2;
2;
[1, 2];
c;
[c, b, a];
["a", "b", "c"];
"a";
"a";
"a";
"b";
3;

Installation

npm install babel-plugin-minify-constant-folding

Usage

.babelrc

{
  "plugins": ["minify-constant-folding"]
}

Via CLI

babel --plugins minify-constant-folding script.js

Via Node API

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

Options

  • tdz - Account for TDZ (Temporal Dead Zone)

© 2018 Sebastian McKenzie
Licensed under the MIT License.
http://babeljs.io/docs/plugins/minify-constant-folding/