z-pattern-matching/z

does not work with typescript

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#35 opened on Dec 1, 2017

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 (3 comments) (0 reactions) (0 assignees)JavaScript (1,714 stars) (78 forks)batch import
bughelp wanted

Description

Strange but when I use some of the snippets with typescript, it always returns the result of the first param. For example

import {matches} from 'z';

const person = { name: 'Maria' }
matches(person)(
  (x = { name: 'John' }) => console.log('John you are not welcome!'),
  (x)                    => console.log(`Hey ${x.name}, you are welcome!`)
)

returns John you are not welcome.

Contributor guide

Tech stack
javascripttypescript
Domain
full stack
Issue type
bug
DifficultyEstimated implementation difficulty for a new contributor, from 1 for very small changes to 5 for expert-level work.
3
Estimated timeA rough time range for an experienced contributor to investigate, implement, test, and prepare a pull request.
1-3 hours
Activity statusHow available the issue appears right now: fresh, active, stale, blocked, or waiting on maintainer input.
stale
ClarityHow clearly the issue explains the expected change, acceptance criteria, and next step.
mostly clear
Prerequisites
basic understanding of TypeScript type inference
Newbie friendlinessA 1-100 score estimating how approachable this issue is for first-time contributors.
40
Research direction
Investigate the source code of the z library, particularly the `matches` function and how it handles TypeScript type bindings. Look for any type guard or conditional types that might cause the first case to always match. Check the library's type definitions and test files for similar patterns.