await_reactpromise_shape.mjs
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await_reactpromise_shape.mjs
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	function ReactPromiseShape(value) {
	this.value = value;
	}

	ReactPromiseShape.prototype = Object.create(Promise.prototype);
	ReactPromiseShape.prototype.constructor = ReactPromiseShape;
	let lastThis = null;
	ReactPromiseShape.prototype.then = function(resolve, _reject) {
	lastThis = this;
	resolve(this.value);
	};

	async function main() {
	const first = new ReactPromiseShape([1]);
	console.log(`first.then.type:${typeof first.then}`);
	console.log(`first.hasOwn.then:${Object.prototype.hasOwnProperty.call(first, 'then')}`);
	console.log(`proto.hasOwn.then:${Object.prototype.hasOwnProperty.call(ReactPromiseShape.prototype, 'then')}`);
	console.log(`first.then.eq.proto:${first.then === ReactPromiseShape.prototype.then}`);

	const awaited = await first;
	console.log(`await.protoThen.isUndefined:${awaited === undefined}`);
	console.log(`await.protoThen.isArray:${Array.isArray(awaited)}`);
	console.log(`await.protoThen.0:${String(awaited?.[0])}`);
	console.log(`await.protoThen.thisEqInstance:${lastThis === first}`);

	const second = new ReactPromiseShape([2]);
	lastThis = null;
	const resolved = await Promise.resolve(second);
	console.log(`promiseResolve.protoThen.isUndefined:${resolved === undefined}`);
	console.log(`promiseResolve.protoThen.isArray:${Array.isArray(resolved)}`);
	console.log(`promiseResolve.protoThen.0:${String(resolved?.[0])}`);
	console.log(`promiseResolve.protoThen.thisEqInstance:${lastThis === second}`);
	}

	await main();