eslint-plugin-toplevel

An eslint plugin for disallow side effect at module toplevel

Why?

Side effect in toplevel of a module are hard to reason, and behave diffrently in CommonJS and ES6 modules. And there is no way to import a module without it's side effects. Solution is simple: Don't make side effect at top level.

Example

$3

``JS
console.log('hello world');
let s=0;
for (let i=0;i<10;i++) {
s += i;
}
console.log(s);
fetch('/api').then(res=>res.text()).then(console.log);
`

$3

`JS
export async function main() {
console.log('hello world');
let s=0;
for (let i=0;i<10;i++) {
s += i;
}
console.log(s);
const res = await fetch('/api');
console.log(await res.text());
}
`

And then in html:

`HTML

`

Or in nodejs make a runner.mjs file:
`JS
import { main } from "./main.mjs";
main();
`

Rules

There are three rules in this plugin:

$3

Disallow var usage at toplevel module.
Goal of this rule is to prevent modules to have internal state.

$3

similiar to no-toplevel-var

$3

Disallow any side effect at top level

Contributing

I'd love to accept your patches and contributions to this project.
There are many ways you can contribute. For example:
* Add tests
* Fix bugs
* Add option to ignore module.exports assigns in no-toplevel-side-effect` rule
* Add good documention