@a11d/converter

Tools for converting between back-end payloads and domain classes, declared per member with a @converter decorator.

Installation

npm install @a11d/converter

Usage

import { construct, converter, deconstruct, type Converter } from '@a11d/converter'

@converter('bit')
class BitConverter implements Converter<'0' | '1', boolean> {
	construct(value: '0' | '1') {
		return value === '1'
	}

	deconstruct(value: boolean) {
		return value ? '1' : '0'
	}
}

declare global {
	interface ConvertersByKeys {
		'bit': BitConverter
	}
}

class Task {
	@converter({ done: 'bit' }) isDone = false
	@converter({ construct: (value: string) => value.trim() }) title = ''
}

const task = construct(Task, { done: '1', title: ' Write the docs ' })
deconstruct(task) // { title: 'Write the docs', done: '1' }

API

| Name | Kind | Description | | --- | --- | --- | | CompositeConverter | class | Tries each converter in turn and takes the first value that is neither null nor undefined. | | definitionsOf | function | Every definition a class carries, its own and its ancestors'. | | extractDirections | function | Resolves the converter options of a member into the keys and converters it reads from and writes to. | | define | function | Records the converter options of a member on its class, rejecting a second member that deconstructs into the same key. | | construct | function | Builds an instance from an incoming representation, running each member's in converters. | | deconstruct | function | Reduces an instance to its outgoing representation, running each member's out converters. | | converters | const | The converters registered by key, filled by @converter on a class and looked up for the keys a member names. | | converter | const | Registers the decorated converter class under a key, or applies a converter to the decorated member. | | Converter | interface | A bidirectional conversion between how a value arrives and how the domain holds it. | | ConverterKey | type | The keys consumers register through ConvertersByKeys. | | ConverterKeys | type | A registered key, or a fallback chain of them — the first converter yielding a value wins. | | ConverterOption | type | A converter itself, a registered key, or nothing — the last one maps a key across without converting. | | ConverterDefinition | type | One direction: a single option for the member's own key, or a map of the keys it maps against. | | ConverterOptions | type | What @converter takes on a member: one definition for both directions, or separate in and out definitions. | | ConverterDirections | type | Which keys a member reads from and writes to, in declaration order. |

Links

• Changelog
• Source

License

MIT © a11delavar