Abstracting patterns for multiple use

[zaferkadi]

First of all, amazing library, use it everyday.

I have the following case where I use matchers and patterns together (apologies If I already butchered or mixed up the terms, still learning).

import { isMatching, match, P, Pattern } from "ts-pattern";

interface FileInfo {
  size: number;
}

// I can define a pattern
const bigFileSizePattern: Pattern.Pattern<FileInfo> = {
  size: P.when((size) => size > 30000),
};

// I can use this pattern 
export const bigFileSizeMatcher = isMatching<Pattern.Pattern<FileInfo>>(bigFileSizePattern);
bigFileSizeMatcher({ size: 30001 }); // true

export const matchFile = (file: FileInfo) =>
  match(file)
    .with(
      bigFileSizePattern,
      () => `above 30mb`
    ).run();

What I achieved with this is I was able to define one pattern, and not duplicate it when using isMatching, or inside with().

However, when I start adding more patterns, like this:

const smallFileSizePattern: Pattern.Pattern<FileInfo> = {
  size: P.when((size) => size <= 30000),
};

const smallFileSizeMatcher = isMatching<Pattern.Pattern<FileInfo>>(smallFileSizePattern);

// And use both in my matchFile function, I get an errors

export const matchFile = (file: FileInfo) =>
  match(file)
    .with(
      bigFileSizePattern,
      () => `above 30mb`,

    ).with(
      smallFileSizePattern,
      () => `below 30mb`
    )
    .run();

I get an error always on the second with(), some infer problem that I can't decipher.
I could be doing something wrong, or what i am trying to achieve is not possible.
I appreciate any help on this 🙏