README.md

SafeScript

This package intent is to make "safe" JavaScript runtime by checking types at runtime and disallowing most of implicit coercion

How to use this "safe" JavaScript runtime

In Node project add in package.json:

  "main": "dist/index.js",
  "scripts": {
    "prepare": "safec ./src -d ./dist --src-map true --allow-ts",
    "start": "npm run prepare && node ./dist/index.js"
  },
  "devDependencies": {
    "typescript-plugin-safescript": "^0.5.3"
  },
  "dependencies": {
    "@redradist/module-runtime-safescript": "^0.4.1"
  }

Then in your main script before any code import @redradist/module-runtime-safescript runtime:

import "@redradist/module-runtime-safescript";

let y = 8;

...

y += "233"; // Possible error behaviour

...

The dist/index.js will look like:

import "@redradist/module-runtime-safescript";

let y = 8;

...

y = SafeScript.add(y, "233"); // SafeScript will throw TypeError exception

...

Now you can go in your code and fix the issue:

import "@redradist/module-runtime-safescript";

let y = 8;

...

y += Number("233"); // Now it is "safe" behaviour

...

Using this SafeScript runtime fills like Python on V8 ;)

Philosophy

The Philosophy of SafeScript:

1. Allow subset of "safe" operations in JavaScript and TypeScript
2. Do not introduce a new valid behaviour in runtime, in such way it is easier just to remove SafeScript runtime at anytime