255396 2023-04-13 07:56:39 -0700 Unexpected 'var' resolution in module 2023-04-20 10:50:05 -0700 1 1 1 Unclassified WebKit JavaScriptCore Safari 16 Unspecified Unspecified RESOLVED INVALID https://bugs.webkit.org/show_bug.cgi?id=223533 InRadar P2 Normal --- 1 tzvetelin.vassilev webkit-unassigned mark.lam webkit-bug-importer ysuzuki oldest_to_newest 1948489 0 tzvetelin.vassilev 2023-04-13 07:56:39 -0700 Problem is observed with emscripten build. Generated Module looks in this way: // Module.mjs var Module = (() => { var _scriptDir = import.meta.url; return ( async function(Module = {}) { console.log(Module) // result is null, expected value is data var Module = typeof Module != "undefined" ? Module : {}; console.log(Module) // result is {} // emscripten stuff } ); })(); export default Module; After import like this: // index.mjs let factory = (await import("Module.mjs")).default await Module({/* data */}) Something is got wrong and Module value is lost. 1950060 1 webkit-bug-importer 2023-04-20 07:57:21 -0700 <rdar://problem/108318013> 1950094 2 ysuzuki 2023-04-20 09:23:26 -0700 That's correct behavior. module's global scope is Module lexical environment. Not global scope.