• proxy-handler-decorators
  • Functions
    • AllowGetTarget
    • DefaultToPrimitive
    • DefaultToStringTag
    • Mapped
    • TargetAsThis
    • getTarget

proxy-handler-decorators

Class decorators for proxy handlers.

Example

A proxy to transform an array, prepending a '!' character to each element.

import {
  getTarget,
  AllowGetTarget,
  Mapped,
  DefaultToPrimitive,
  DefaultToStringTag,
  TargetAsThis,
} from 'proxy-handler-decorators';
import { DefaultProxyHandler } from 'default-proxy-handler';

let counter = 0;
function addBang(words: string[]): string[] {
  counter++;
  return words.map((word) => `${word}!`);
}

@AllowGetTarget
@Mapped<string[]>(addBang)
@DefaultToPrimitive
@DefaultToStringTag
@TargetAsThis
class MappedProxyHandler extends DefaultProxyHandler<string[]> {}
const mappedProxyHandler = new MappedProxyHandler();

const proxy = new Proxy(['hello', 'world'], mappedProxyHandler);
expect(counter).toBe(0);
expect(proxy).toEqual(['hello!', 'world!']);
expect(counter).toBeGreaterThan(0);

counter = 0;
expect(proxy).toEqual(['hello!', 'world!']);
expect(counter).toBeGreaterThan(0);

expect(getTarget(proxy)).toEqual(['hello', 'world']);

Functions

AllowGetTarget

▸ AllowGetTarget<T, SuperClass>(superClass): SuperClass

The decorator to enable getTarget function.

Type parameters

| Name | Type | | :------ | :------ | | T | extends object | | SuperClass | extends (...args: any[]) => ProxyHandler<T> |

Parameters

| Name | Type | | :------ | :------ | | superClass | SuperClass |

Returns

SuperClass

Defined in

index.ts:194

DefaultToPrimitive

▸ DefaultToPrimitive<T, SuperClass>(superClass): SuperClass

A decorator to add a default implementation of [Symbol.toPrimitive] method to the proxy.

Type parameters

| Name | Type | | :------ | :------ | | T | extends object | | SuperClass | extends (...args: any[]) => ProxyHandler<T> |

Parameters

| Name | Type | | :------ | :------ | | superClass | SuperClass |

Returns

SuperClass

Defined in

index.ts:114

DefaultToStringTag

▸ DefaultToStringTag<T, SuperClass>(superClass): SuperClass

A decorator to add a default implementation of [Symbol.toStringTag] method to the proxy.

Type parameters

| Name | Type | | :------ | :------ | | T | extends object | | SuperClass | extends (...args: any[]) => ProxyHandler<T> |

Parameters

| Name | Type | | :------ | :------ | | superClass | SuperClass |

Returns

SuperClass

Defined in

index.ts:150

Mapped

▸ Mapped<T>(mapper): (proxyHandlerConstructor: (...args: any[]) => ProxyHandler<T>) => void

Type parameters

| Name | Type | | :------ | :------ | | T | extends object |

Parameters

| Name | Type | | :------ | :------ | | mapper | (from: T) => T |

Returns

fn

▸ (proxyHandlerConstructor): void

Parameters

| Name | Type | | :------ | :------ | | proxyHandlerConstructor | (...args: any[]) => ProxyHandler<T> |

Returns

void

Defined in

index.ts:212

TargetAsThis

▸ TargetAsThis<T, SuperClass>(superClass): SuperClass

A decorator to bind this to the proxy target for all instance methods on the proxy.

Type parameters

| Name | Type | | :------ | :------ | | T | extends object | | SuperClass | extends (...args: any[]) => ProxyHandler<T> |

Parameters

| Name | Type | | :------ | :------ | | superClass | SuperClass |

Returns

SuperClass

Defined in

index.ts:78

getTarget

▸ getTarget<T>(maybeProxy): T | undefined

Returns the proxy target if proxy is a proxy and its proxy handler has the AllowGetTarget decorator, or undefined otherwise.

Type parameters

| Name | | :------ | | T |

Parameters

| Name | Type | | :------ | :------ | | maybeProxy | T |

Returns

T | undefined

Defined in

index.ts:187