Bug 264400

Summary: Modules with top-level await should not block execution of sibling modules
Product: WebKit Reporter: nicolo.ribaudo
Component: JavaScriptCoreAssignee: Nobody <webkit-unassigned>
Status: NEW ---    
Severity: Normal CC: mark.lam, nicolo.ribaudo, webkit-bug-importer, ysuzuki
Priority: P2 Keywords: InRadar
Version: Safari 17   
Hardware: Unspecified   
OS: Unspecified   

Description nicolo.ribaudo 2023-11-08 04:32:21 PST
Consider the following module:

    import "a"
    import "b"

and assume that "a" uses top-level await. The expected execution order is:
1. "a" starts executing, and then pauses at the await
2. "b" gets executed
3. at some point, "a" finishes executing

However, this is what is currently happening in Safari:
1. "a" starts executing, and then pauses at the await
2. at some point, "a" finishes executing
3. then "b" gets executed

I submitted a WPT test for this at https://github.com/web-platform-tests/wpt/pull/42944
Comment 1 Radar WebKit Bug Importer 2023-11-15 04:33:13 PST
<rdar://problem/118449289>