Minify constant folding

尝试表达式求值并嵌入结果。现在只处理数字和字符串

示例

输入

"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;

输出

"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;

安装

npm install babel-plugin-minify-constant-folding

使用

通过 .babelrc (推荐)

.babelrc

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

通过 CLI

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

通过 Node API

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

可选项

  • tdz - TDZ的配置 (Temporal Dead Zone)(暂时性死区)