Bug 1681046 - Enable Top Level Await by default r=mgaudet

Differential Revision: https://phabricator.services.mozilla.com/D110394

js/public/CompileOptions.h

@@ -131,7 +131,7 @@ class JS_PUBLIC_API TransitiveCompileOptions {
   bool nonSyntacticScope = false;
   bool privateClassFields = false;
   bool privateClassMethods = false;
-  bool topLevelAwait = false;
+  bool topLevelAwait = true;
 
   // True if transcoding to XDR should use Stencil instead of JSScripts.
   bool useStencilXDR = false;

js/public/ContextOptions.h

@@ -49,7 +49,7 @@ class JS_PUBLIC_API ContextOptions {
         fuzzing_(false),
         privateClassFields_(false),
         privateClassMethods_(false),
-        topLevelAwait_(false) {
+        topLevelAwait_(true) {
   }
 
   bool asmJS() const { return asmJS_; }

js/src/jsapi-tests/testStencil.cpp

@@ -95,8 +95,9 @@ bool basic_test(const CharT* chars) {
   JS::RootedValue rval(cx);
   CHECK(JS::ModuleInstantiate(cx, moduleObject));
   CHECK(JS::ModuleEvaluate(cx, moduleObject, &rval));
-  CHECK(rval.isUndefined());
+  CHECK(!rval.isUndefined());
 
+  js::RunJobs(cx);
   CHECK(JS_GetProperty(cx, global, "x", &rval));
   CHECK(rval.isNumber() && rval.toNumber() == 42);
 
@@ -339,8 +340,9 @@ BEGIN_TEST(testStencil_OffThreadModule) {
   JS::RootedValue rval(cx);
   CHECK(JS::ModuleInstantiate(cx, moduleObject));
   CHECK(JS::ModuleEvaluate(cx, moduleObject, &rval));
-  CHECK(rval.isUndefined());
+  CHECK(!rval.isUndefined());
 
+  js::RunJobs(cx);
   CHECK(JS_GetProperty(cx, global, "x", &rval));
   CHECK(rval.isNumber() && rval.toNumber() == 42);
 

js/src/shell/js.cpp

@@ -630,7 +630,7 @@ bool shell::enablePropertyErrorMessageFix = false;
 bool shell::enableIteratorHelpers = false;
 bool shell::enablePrivateClassFields = false;
 bool shell::enablePrivateClassMethods = false;
-bool shell::enableTopLevelAwait = false;
+bool shell::enableTopLevelAwait = true;
 bool shell::useOffThreadParseGlobal = true;
 #ifdef JS_GC_ZEAL
 uint32_t shell::gZealBits = 0;

js/xpconnect/src/XPCJSContext.cpp

@@ -975,6 +975,9 @@ static void ReloadPrefsCallback(const char* pref, void* aXpccx) {
   sWeakRefsExposeCleanupSome = Preferences::GetBool(
       JS_OPTIONS_DOT_STR "experimental.weakrefs.expose_cleanupSome");
 
+  bool topLevelAwaitEnabled =
+      Preferences::GetBool(JS_OPTIONS_DOT_STR "experimental.top_level_await");
+
   // Require private fields disabled outside of nightly.
   bool privateFieldsEnabled = false;
   bool privateMethodsEnabled = false;
@@ -987,13 +990,6 @@ static void ReloadPrefsCallback(const char* pref, void* aXpccx) {
       Preferences::GetBool(JS_OPTIONS_DOT_STR "experimental.private_methods");
 #endif
 
-  // Require top level await disabled outside of nightly.
-  bool topLevelAwaitEnabled = false;
-#ifdef NIGHTLY_BUILD
-  topLevelAwaitEnabled =
-      Preferences::GetBool(JS_OPTIONS_DOT_STR "experimental.top_level_await");
-#endif
-
 #ifdef JS_GC_ZEAL
   int32_t zeal = Preferences::GetInt(JS_OPTIONS_DOT_STR "gczeal", -1);
   int32_t zeal_frequency = Preferences::GetInt(

modules/libpref/init/StaticPrefList.yaml

@@ -5592,13 +5592,13 @@
     type: bool
     value: false
     mirror: always
+#endif  // NIGHTLY_BUILD
 
   # Experimental support for Top-level Await in JavaScript.
 -   name: javascript.options.experimental.top_level_await
     type: bool
-    value: false
+    value: true
     mirror: always
-#endif  // NIGHTLY_BUILD
 
 # The amount of time we wait between a request to GC (due to leaving a page) and doing the actual GC, in ms.
 - name: javascript.options.gc_delay