rauschma

Creating standalone ESM-based Node.js scripts on Unix and Windows

Approach:

1. The file starts with shell code.
2. That code uses Node.js to execute the file in ESM mode, after it removes the initial non-JavaScript lines.
   • Node.js does not currently have CLI flags for achieving what we do in this step. Therefore, we have to pipe to the node executable.

When editing this file, we want to use the JavaScript mode of our IDE or editor. Therefore, we try to “hide” the shell code from JavaScript as much as possible.

WebReflection

Update

If you're OK in having a node-esm executable, please consider this solution.

#!/usr/bin/env sh
# the /usr/local/bin/node-esm executable
input_file=$1
shift
exec node --input-type=module - $@ <$input_file

sebmarkbage

The Rules of React

All libraries have subtle rules that you have to follow for them to work well. Often these are implied and undocumented rules that you have to learn as you go. This is an attempt to document the rules of React renders. Ideally a type system could enforce it.

What Functions Are "Pure"?

A number of methods in React are assumed to be "pure".

On classes that's the constructor, getDerivedStateFromProps, shouldComponentUpdate and render.