Diffusion Ant (mir/gc) Code

ant/tests/test_native_cfunc_object_semantics_repro.cjs
445f58992868mir/gc

test_native_cfunc_object_semantics_repro.cjs
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			function snapshotAssignmentAlias() {
			const f = fetch;
			const obj = {};

			obj.a = f;
			obj.b = f;

			return {
			fetchType: typeof fetch,
			fetchName: fetch.name,
			sameStoredValue: obj.a === obj.b,
			sameAsFetchA: obj.a === fetch,
			sameAsFetchB: obj.b === fetch,
			storedNames: {
			a: obj.a && obj.a.name,
			b: obj.b && obj.b.name,
			},
			};
			}

			function snapshotPromotedState() {
			const sym = Symbol('native-fn-repro');
			const originalProto = Object.getPrototypeOf(fetch);
			const customProto = { fromCustomProto: 42 };

			fetch.extra = 'value-from-set';
			Object.defineProperty(fetch, 'defined', {
			value: 'value-from-defineProperty',
			enumerable: true,
			configurable: true,
			writable: true,
			});
			Object.defineProperty(fetch, sym, {
			value: 'symbol-value',
			enumerable: true,
			configurable: true,
			writable: true,
			});
			Object.setPrototypeOf(fetch, customProto);

			const names = Object.getOwnPropertyNames(fetch);
			const symbols = Object.getOwnPropertySymbols(fetch);
			const descExtra = Object.getOwnPropertyDescriptor(fetch, 'extra');
			const descDefined = Object.getOwnPropertyDescriptor(fetch, 'defined');
			const descSym = Object.getOwnPropertyDescriptor(fetch, sym);

			const snapshot = {
			extraRead: fetch.extra,
			definedRead: fetch.defined,
			protoWasUpdated: Object.getPrototypeOf(fetch) === customProto,
			inheritedRead: fetch.fromCustomProto,
			ownNames: names,
			ownSymbols: symbols.map((entry) => String(entry)),
			hasExtraName: names.includes('extra'),
			hasDefinedName: names.includes('defined'),
			hasSymbol: symbols.includes(sym),
			extraDescriptor: descExtra && {
			value: descExtra.value,
			enumerable: descExtra.enumerable,
			configurable: descExtra.configurable,
			writable: descExtra.writable,
			},
			definedDescriptor: descDefined && {
			value: descDefined.value,
			enumerable: descDefined.enumerable,
			configurable: descDefined.configurable,
			writable: descDefined.writable,
			},
			symbolDescriptor: descSym && {
			value: descSym.value,
			enumerable: descSym.enumerable,
			configurable: descSym.configurable,
			writable: descSym.writable,
			},
			};

			delete fetch.extra;
			delete fetch.defined;
			delete fetch[sym];
			Object.setPrototypeOf(fetch, originalProto);

			return snapshot;
			}

			const result = {
			assignmentAlias: snapshotAssignmentAlias(),
			promotedState: snapshotPromotedState(),
			};

			console.log(JSON.stringify(result, null, 2));

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