babel-plugin-unsafe-optimizations-duplicated-globals

This plugin creates local variables to store values of global variables.

This allows better minification of global variables usages.

For example:

const array1 = Array.from(data1);
const array2 = Array.from(data2);
const array3 = Array.from(data3);
const array4 = Array.from(data4);
const array5 = Array.from(data5);

will be transformed to:

const a = Array;
const array1 = a.from(data1);
const array2 = a.from(data2);
const array3 = a.from(data3);
const array4 = a.from(data4);
const array5 = a.from(data5);

Why is it unsafe?

It's unsafe because it assumes that values of global variables will not be changed. Assigning a new value to a global variable will not get reflected in the app after this transform.

This plugin can be used if you are sure that global variables are not going to be changed.

Configuration

target

Selects JavaScript syntax version for the output code. Supported values are: "es5", "es6".

includeGlobal

Array of strings, which specifies globals to transform, all other globals will be ignored.

excludeGlobal

Array of strings, which specifiec global to ignore during transform.