291255 2025-04-08 00:26:17 -0700 `export async function` changes prototype to Function instead of AsyncFunction 2025-04-11 15:17:18 -0700 1 1 1 Unclassified WebKit JavaScriptCore WebKit Nightly Build Unspecified Unspecified RESOLVED FIXED InRadar P2 Normal --- 1 jarred ysuzuki keith_miller webkit-bug-importer ysuzuki oldest_to_newest 2109664 0 jarred 2025-04-08 00:26:17 -0700 The following code doesn't throw an error in node/v8 and does throw an error in JSC: ``` export async function a() {} async function b() {} async function c() {} if (Object.getPrototypeOf(a) !== Object.getPrototypeOf(c)) { throw new Error("Expected export declaration & export function to have same prototype"); } if (Object.getPrototypeOf(a) !== Object.getPrototypeOf(b)) { throw new Error("Expected export & non-exported functions to have same prototype"); } if (Object.getPrototypeOf(a).constructor !== Object.getPrototypeOf(c).constructor) { throw new Error("Expected export declaration & export function to have same constructor"); } if (Object.getPrototypeOf(a).constructor !== Object.getPrototypeOf(b).constructor) { throw new Error("Expected export & non-exported functions to have same constructor"); } if (Object.getPrototypeOf(a).constructor.name !== "AsyncFunction") { throw new Error("Expected AsyncFunction"); } globalThis.print ??= console.log; const AsyncFunction = Object.getPrototypeOf(a).constructor; // This should not throw new AsyncFunction("await 42")(); export { c }; ``` Originally reported in https://github.com/oven-sh/bun/issues/18137 2110501 1 webkit-bug-importer 2025-04-11 12:32:38 -0700 <rdar://problem/149083588> 2110503 2 ysuzuki 2025-04-11 12:44:45 -0700 Pull request: https://github.com/WebKit/WebKit/pull/43970 2110561 3 ews-feeder 2025-04-11 15:17:16 -0700 Committed 293602@main (910c1b00a197): <https://commits.webkit.org/293602@main> Reviewed commits have been landed. Closing PR #43970 and removing active labels.