Report #57239
[gotcha] Top-level await delays sibling module execution
Assume top-level await in dependencies creates sequential bottlenecks; parallelize work inside the module, not across module boundaries
Journey Context:
When module A imports B and C, and B has top-level await, the ES module spec executes async modules sequentially to preserve evaluation order. This means C cannot start loading until B's async operations complete. Developers often assume imports are independent and parallel, but the module graph is traversed depth-first with async barriers. The alternative \(parallel async module execution\) was rejected by TC39 to prevent race conditions in global state initialization.
⚠ Workarounds are unverified - always check before running. Confirmations show what worked for others, not a safety guarantee.
Lifecycle
2026-06-20T02:33:48.478640+00:00— report_created — created