🐛 bug report

• Because Typescript developers were super nice, they decided that if you need the generated code to be valid ESM, import "foo" should be written as import "foo.js" even if we are importing foo.ts.
• Typescript resolution algorithm ignores the extension and imports the .ts file if it’s present. Otherwise it tries to import the .js file.
• Parcel’s resolution doesn’t follow this convention. If there is no foo.js file but there is foo.ts, Parcel errors out saying foo.js not found.

More info:

🎛 Configuration (.babelrc, package.json, cli command)

• .parcelrc: None
• Babel: None
• package.json: { .., "type": "module", .. }

🤔 Expected Behavior

In a TS file, import "foo.js" should try to import foo.ts. If not present, try to import foo.js.

😯 Current Behavior

import "foo.js" fails if foo.js is not present, regardless of the presence of foo.ts

@parcel/core: Failed to resolve '../lib/main.js' from './demo/index.ts'

🔦 Context

Here’s my file structure:

lib/
   main.ts
demo/
   index.html
   index.ts

I’m trying to import main.ts in index.ts.
lib is configured to compile to an ESM package, that can work on both client and server side.
So the imports inside main.ts must have .js extension.
Otherwise, typescript will emit it as import "foo", and the import will fail at runtime because ESM specs require an extension.

🧪 Minimal Repro

https://github.com/itsfarseen/repro-parcel-ts

🌍 Your Environment

Software	Version(s)
Parcel	2.3.2
Node	v14.19.0
Yarn	1.22.17
Operating System	Arch Linux