esm-env-robust

Like esm-env, uses export conditions to return environment information in a way that works with major bundlers and runtimes, but this project is also 'robust' in the sense it have also a fallback bahaviour for older environments that doesn't support the exports fields in package.json.

This project was motivated to solve issue esm-env#1, but works for wider audience.

Demo of fallback in old environment: https://svelte.dev/repl/6ae4871d6a48460fb8be28afaf9a6e1d?version=3.54.0

Usage

1. Install with npm install esm-env-robust.
2. Import according to the desired behaviour:
   • If you want to detect only whether the environment is the browser or not, use:

       import { BROWSER } from 'esm-env-robust';

   • If you (also) need to check whether the environment is production or development, you need to specify what is the fallback behaviour for older environment by the import path:
     • If the desired fallback is that DEV will be false, use:

     import { DEV, BROWSER } from 'esm-env-robust/dev-fallback-false';

     • If the desired fallback is that DEV will be true, use:

     import { DEV, BROWSER } from 'esm-env-robust/dev-fallback-true';

If you don't care about fallback behaviour for older environments at all, consider using the basic esm-env package instead.

Fallback value of BROWSER

The fallback value of BROWSER is set up on runtime by checking the value of typeof window. Currently, code minification tools, as far as we know, don't optimize this value to compile time. That means you enjoy the most of both worlds by using this package - on updated environments you'll get the correct value on compile time, and on older environments you'll get the correct value on runtime (better than nothing).

License

MIT