• 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