TSError: The inferred type of 'MY_PATTERN' cannot be named without a reference to '<path>/ts-pattern/dist/types/Pattern'

[GGomez99]

Describe the bug

When working in a yarn project with many workspaces, and having this compilerOptions in their tsconfig.json:

"compilerOptions": {
   "moduleResolution": "bundler"
}

I get a TS error when I try to directly export a Pattern without explicitly typing its type:

The inferred type of 'MY_PATTERN' cannot be named without a reference to '../.yarn/cache/ts-pattern-npm-5.4.0-2464380e11-f757dd3259.zip/node_modules/ts-pattern/dist/types/Pattern'. This is likely not portable. A type annotation is necessary.

TypeScript playground with a minimal reproduction case

Example: Playground

Versions

• TypeScript version: 5.6.2
• ts-pattern version: 5.4.0
• environment: browser / node version

Possible solutions

In order to solve this, we could:

1. Directly export the needed types in the package.json of ts-pattern
2. Put the needed types in a namespace, use it in all the other files and then export that namespace

I think the first solution is the simplest and it won't modify the inferred type names when hovering any ts-pattern functions. The only drawback is that internal types will be exposed through ts-pattern/types but I think that's worth it. I'll make a PR for this!

[lucaschultz]

Having the same problem; I'm missing the Chainable and GuardP types to be able to create a reusable pattern. @gvergnaud, should I whip up another PR, or is someone already on this?

[lucaschultz]

Ah, I think I just realized that there hasn't been a release since this PR was merged. That's probably why I'm having the problem.

Edit: I just patched the changes of #292 locally and it works. Looking forward to the next release 🙂

[gvergnaud]

@GGomez99 's PR has been published as v5.5.0! Closing this issue