zod-pattern
Pattern matching utility powered by Zod schemas.
Overview
zod-pattern provides a simple, typesafe and flexible pattern matching utility based on Zod schemas. With this library, you can validate and transform data using the power of Zod, and easily handle various cases based on the shape and value of the input.
Features
- ⚡ Clear Syntax: Concise and expressive syntax to make your patterns clear and readable.
- 🌟 Full Type Inference: Achieve strong typing for matched data and results with the power of Zod's infer.
- 🚀 Optional Transforms: Either provide static outcomes or utilize dynamic transform functions for matched results.
Installation
npm install zod-patternUsage
Basic Matching
Define patterns using Zod schemas and corresponding results:
import { pattern } from "zod-pattern";
import { z } from "zod";
type Strength = "strong" | "medium" | "weak";
const predictionMatcher = pattern()
.returnType<Strength>()
.case(z.number().gte(0.8), "strong")
.case(z.number().gte(0.5), "medium")
.default("weak");
const result = predictionMatcher.match(0.97); // "strong"Matching with Transform Functions
Transform matched data on-the-fly:
const predictionMatcher = pattern()
.case(z.number().gte(0.8), (value) => `strong (${value * 100}%)`)
.case(z.number().gte(0.5), (value) => `medium (${value * 100}%)`)
.default((value) => `weak (${value * 100}%)`);
const result = predictionMatcher.match(0.97); // "strong (97%)"Matching Partial Objects
Match based on partial object shapes:
const partialMatcher = pattern()
.case(z.object({ key: z.string() }), ({ key }) => `Matched via key: "${key}"`)
.default("not matched");
const result = partialMatcher.match({ key: "magic", unused: "value" }); // `Matched via key: "magic"`Routing Events
Process and route various messages/events:
const messageMatcher = pattern()
.case(textMessageSchema, handleTextMessage)
.case(userUpdateSchema, handleUserUpdate)
.case(connectionSchema, handleConnection)
.case(errorSchema, handleError)
.default((err) => new Error(`Unknown message: ${err}`));License
zod-pattern is MIT licensed.