Allow Setting Extension Priority (and Then Not Requiring Extensions in Imports)

[machineghost]

What is the problem this feature will solve?

In recent years Node has been trading developer convenience for functionality, as several recent changes (eg. https://satanacchio.hashnode.dev/everything-you-need-to-know-about-nodejs-type-stripping#heading-a-predictable-experience) strongly encourage:

import foo from 'foo.js';

over:

import foo from 'foo';

However, for most devs that's a false trade! We can have convenient (extension-less) imports and have the benefits of the new features.

How?

What is the feature you are proposing to solve the problem?

node --prioritizeExtensions=js,jsx,ts,tsx

Now, when Node sees:

import foo from 'foo';

it will treat it as

import foo from 'foo.js';

... unless that fails, in which case it will treat is as:

import foo from 'foo.jsx';

... and so on.

What alternatives have you considered?

Not requiring an argument ... but the dev needs some way to specify "if you see foo.js and foo.ts, but I said from foo, use the .js one".

Look, I know three or four extra characters of typing (.jsx) may not seem like a lot, but it adds up across dozens of imports in hundreds (or thousands) of files. Please, consider letting us have our extension-less imports back.

[marco-ippolito]

You example is not correct:

import foo from 'foo'

Will look for a package foo in the node_modules.
While:

import foo from './foo'

is not allowed.

I'm -1 on having extension guessing.
Node.js would have to do several attempts to read on the fs. A few more characters would save the runtime a lot of overhead which is reasonable.
Also the list would be:
js, cjs, mjs, ts, cts, mts which is quite long.

[machineghost]

You example is not correct:

Sorry, the perils of pseudocode ... but you seemed to grok my intent :)

Node.js would have to do several attempts to read on the fs. A few more characters would save the runtime a lot of overhead which is reasonable.

You seem to be making assumptions for every Node developer. Personally, and I suspect a lot of people would share this preference, I would happily trade 0.5s startup time for never having to write an extension in my imports ever again.

[marco-ippolito]

I mean if it stays behind a flag, I'd not be totally opposed. I would not like to be the default behavior. I'm afraid it will create a flavor that only works for some and not for others.

[machineghost]

I'm afraid it will create a flavor that only works for some and not for others.

Legitimate concern, but my counterarguments would be:

• every new flag does that (to an extent)
• if someone picks the "wrong" flavor and wants to switch, they're probably just a multi-file find/replace or two away from the other flavor
• Node already has "mixed flavors" (both imports with extensions and ones without)