Calculate target JS name more reliably

emcc.py

@@ -1206,8 +1206,13 @@ def phase_setup(state):
   else:
     target = 'a.out.js'
 
-  settings.TARGET_BASENAME_WITH_EXT = os.path.basename(target)
-  settings.TARGET_BASENAME = unsuffixed(settings.TARGET_BASENAME_WITH_EXT)
+  if options.oformat in (OFormat.JS, OFormat.MJS):
+    js_target = target
+  else:
+    js_target = get_secondary_target(target, '.js')
+  settings.TARGET_JS_NAME = js_target
+
+  settings.TARGET_BASENAME = unsuffixed_basename(target)
 
   if settings.EXTRA_EXPORTED_RUNTIME_METHODS:
     diagnostics.warning('deprecated', 'EXTRA_EXPORTED_RUNTIME_METHODS is deprecated, please use EXPORTED_RUNTIME_METHODS instead')
@@ -2558,10 +2563,7 @@ def phase_final_emitting(options, target, wasm_target, memfile):
 
   shared.JS.handle_license(final_js)
 
-  if options.oformat in (OFormat.JS, OFormat.MJS):
-    js_target = target
-  else:
-    js_target = get_secondary_target(target, '.js')
+  js_target = settings.TARGET_JS_NAME
 
   # The JS is now final. Move it to its final location
   move_file(final_js, js_target)

src/settings_internal.js

@@ -32,8 +32,8 @@ var SIDE_MODULE_IMPORTS = [];
 // stores the base name of the output file (-o TARGET_BASENAME.js)
 var TARGET_BASENAME = '';
 
-// stores the base name of the output file with extension (TARGET_BASENAME.js or TARGET_BASENAME.mjs)
-var TARGET_BASENAME_WITH_EXT = '';
+// stores the base name (with extension) of the output JS file
+var TARGET_JS_NAME = '';
 
 // Indicates that the syscalls (which we see statically) indicate that they need
 // full filesystem support. Otherwise, when just a small subset are used, we can

src/worker.js

@@ -168,7 +168,7 @@ self.onmessage = function(e) {
 #endif
 
 #if MODULARIZE && EXPORT_ES6
-      (e.data.urlOrBlob ? import(e.data.urlOrBlob) : import('./{{{ TARGET_BASENAME_WITH_EXT }}}')).then(function({{{ EXPORT_NAME }}}) {
+      (e.data.urlOrBlob ? import(e.data.urlOrBlob) : import('./{{{ TARGET_JS_NAME }}}')).then(function({{{ EXPORT_NAME }}}) {
         return {{{ EXPORT_NAME }}}.default(Module);
       }).then(function(instance) {
         Module = instance;