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装饰器、箭头函数、异步生成器

💻代码

这段代码按预期工作

export default class Que {
	private static async * makeStream(): AsyncGenerator<unknown, any, any> {
		let r = yield
		while (1) r = yield await r()
	}

	q = Que.makeStream()

	constructor() {
		this.q.next()
	}

	add = async <T>(fn: (...args: any[]) => Promise<T>) => (await this.q.next(fn)).value as T
}

export function qued(
	_: unknown,
	__: string,
	descriptor: PropertyDescriptor,
) {
	const que = new Que()
	const original = descriptor.value

	descriptor.value = async function (...args: any[]) {
		return que.add(() => original.call(this, ...args)) as Promise<ReturnType<typeof original>>
	}
}

class Tested {
	count: number[] = []

	@qued
	async testMethod(v: number) {
		return new Promise<number>(resolve => {
			setTimeout(() => {
				this.count.push(v)
				resolve(v)
			}, 20 - v * 2)
		})
	}
}

async function test(){
	const testedInstance = new Tested()

	for (const val of [1,2,3,4,5]) {
		testedInstance.testMethod(val)
	}

	await testedInstance.testMethod(6)

	console.log(testedInstance.count)
}

test()
 // [1,2,3,4,5,6]

这段代码不起作用

export default class Que {
	private static async * makeStream(): AsyncGenerator<unknown, any, any> {
		let r = yield
		while (1) r = yield await r()
	}

	q = Que.makeStream()

	constructor() {
		this.q.next()
	}

	add = async <T>(fn: (...args: any[]) => Promise<T>) => (await this.q.next(fn)).value as T
}

export function qued(
	_: unknown,
	__: string,
	descriptor?: PropertyDescriptor, // <--
) {
	const que = new Que()
	const original = descriptor!.value

	descriptor!.value = async function (...args: any[]) {
		return que.add(() => original.call(this, ...args)) as Promise<ReturnType<typeof original>>
	}
}

class Tested {
	count: number[] = []

	@qued
	testMethod = async (v: number) => { // <-- turn into arrow function
		return new Promise<number>(resolve => {
			setTimeout(() => {
				this.count.push(v)
				resolve(v)
			}, 20 - v * 2)
		})
	}
}

async function test(){
	const testedInstance = new Tested()

	for (const val of [1,2,3,4,5]) {
		testedInstance.testMethod(val)
	}

	await testedInstance.testMethod(6)

	console.log(testedInstance.count)
}

test()
 // [6]

当方法是静态的或者不是箭头函数时，一切都按预期工作。然而，当方法被写成箭头函数时，会发生这种情况。我是不是漏掉了什么？
Que.add()在没有装饰器的情况下按预期工作。