Match

Since v1.3.0

Type-level pattern matching utility. Matches a type against a patterns object and returns the corresponding value, with support for a default case.

Signature

export type Match<T, Patterns extends Record<string, any>> = T extends keyof Patterns
	? Patterns[T]
	: Patterns extends { _: infer Default }
		? Default
		: never

Parameters

Parameter	Description
T	The type to match against patterns
Patterns	An object mapping types to their results

Examples

Basic Usage

import type { Match } from 'uni-types'

type Status = 'success' | 'error' | 'pending'
type StatusMessage = Match<Status, { success: 'OK'; error: 'Failed'; pending: 'Waiting' }>
// 'OK' | 'Failed' | 'Waiting'

With Default Case

import type { Match } from 'uni-types'

type Color = 'red' | 'green' | 'blue'
type HexColor = Match<Color, { red: '#ff0000'; green: '#00ff00'; _: '#000000' }>
// '#ff0000' | '#00ff00' | '#000000' (blue matches default)