Does not seem to resolve discriminated unions correctly about ts-pattern

[JUSTIVE]

you should use narrowed instances to benefit from pattern matching.

match(object)
    .with({type:"variant1"}, (object) => {
      console.log(object.data.someField);
      console.log(object.flavor);
    })
    .with({type:"variant2"}, (object) => {
      console.log(object.data.length);
      console.log(object.kind);
    })
    .exhaustive();
};

[ian-schu]

Thanks guys! I had no idea I was supposed to be matching on the whole object. It's interesting that the native TS switch will do this exactly as I hoped 🤔

Anyway, I am unblocked on this 👍🏻

Really interested in the TS 5.5 predicate inference. Seems like that would allow match() to behave a lot more like the native switch that I gave in my sandbox.

[gvergnaud]

Yes, as @JUSTIVE showed, you need to match on the whole object and use the narrowed reference that's provided as a parameter to handler functions.

I wish there was a way to narrow an object that's in scope based on the pattern given to .with, but it isn't possible today.

[JUSTIVE]

maybe there's some point where we could benefit from typescript 5.5's type predicate inference. not sure how we'll benefit from it, but since it automatically narrows type, I'm pretty sure there's some way.