nightshirt

nightshirt lets you define strongly-typed Immutable.js Records in TypeScript.

nightshirt requires TypeScript 2.1, as it uses keyof and lookup types.

Installation

nightshirt is available via NPM:

npm install --save nightshirt

Usage

Immutable.js provides a Record function for creating record classes, and nightshirt works similarly. Define an interface with your record's properties, and then call makeRecordFactory<T> to create your record class.

Records are of type Record<T>, which makes all properties on T into readonly versions of those properties, and mixes in the methods available on Immutable.js records: get, set, merge, etc.

import makeRecordFactory, {Record} from 'nightshirt'

interface Contact {
    name: string
    email: string
    private: boolean
}

const Contact = makeRecordFactory<Contact>({
    name: '',
    email: '',
    private: false
})

let c: Record<Contact> = new Contact()
c = c.set('private', true)
// c.private = false         // error: 'private' is a read-only property
// c = c.set('private', 2)   // error: `2` is not a boolean (Contact['private'])
// c = c.set('phone', '...') // error: `'phone'` is not 'name' | 'email' | 'private'

c = c.withMutations((c) => {
    c.name = 'Bugs Bunny'
    e.email = '[email protected]'
})
c = c.merge({
    email: '[email protected]',
    private: false
})