Simple Type Matcher

A lightweight pattern matching utility for JavaScript/TypeScript that provides flexible object matching capabilities.

Installation

npm install simple-type-matcher
# or
yarn add simple-type-matcher

Features

• Simple and intuitive API
• TypeScript support
• Flexible matching patterns
• Built-in matcher helpers
• Support for custom matching functions

Usage

Basic Matching

import matcher from "simple-type-matcher";

// Simple value matching
matcher({name: "John"}, {name: "John"}); // true
matcher({age: 25}, {age: 30}); // false

// Truthy value matching
matcher({active: true}, {active: true}); // true
matcher({active: "yes"}, {active: true}); // true

Using Matcher Helpers

import matcher, {match} from "simple-type-matcher";

// Match any value
matcher({data: "anything"}, {data: match.anything()}); // true

// Match by type
matcher(
  {name: "John", age: 25},
  {
    name: match.any(String),
    age: match.any(Number),
  }
); // true

Custom Matching Functions

import matcher from "simple-type-matcher";

// Using custom matching functions
matcher({number: 42}, {number: (value) => value % 2 === 0}); // true

matcher({text: "Hello"}, {text: (value) => value.length > 10}); // false

API Reference

matcher(objectToMatch: object, matchers: Matchers): boolean

The main function that performs the matching operation.

• objectToMatch: The object to be matched against
• matchers: An object containing the matching rules
• Returns: true if all matchers pass, false otherwise

Matcher Helpers

match.anything(): MatcherFn

Returns a matcher function that always returns true.

match.any(type: String | Number | Boolean | Object | Function): MatcherFn

Returns a matcher function that checks if a value is of the specified type.

TypeScript Support

The library is written in TypeScript and includes type definitions. The main types are:

• MatcherFn: A function that takes any value and returns a boolean
• ValueType: Union type of possible matcher values
• Matchers: Type for the matchers object

License

MIT © Becca Bailey