babel-preset-mjs

Babel preset to transpile JS to restricted mjs JS.

Features

Restriction	Solution
No String, Number, RegExp, Date, Function, etc.	Not solved
No try/catch/finally.	Transpiled to functions that make try/catch/finally work.
No error classes.	Not solved
No `new` or prototypes. In order to create an object with a custom prototype, use `Object.create()`, which is available.	`new` is handled by `Object.create()`, and the constructor is called on the resultant object
Strict mode only. No `for..of`, `=>`, destructors, generators, proxies, promises, classes, template strings.	Handled by `babel-preset-es2015` (included by default).
No `var`, only `let`.	All uses of `var` are changed to `let`.
No getters, setters, `valueOf`.	Not solved
No `==` or `!=`, only `===` and `!==`.	All uses of `==` are transpiled to a manually evaluated loose equals.
`load()` is used to load external JS, not very standardized and pollutes the global scope.	Not solved
No `setTimeout()` and `setInterval()` API.	Polyfilled using `api_timer.js`.

.babelrc:

{
  "presets": [
    "mjs"
  ]
}

Licensed under MIT license.