Bug 1427610 - Implement import.meta in the browser r=bkelly

dom/script/ScriptLoader.cpp

@@ -785,6 +785,34 @@ HostResolveImportedModule(JSContext* aCx, JS::Handle<JSObject*> aModule,
   return ms->ModuleRecord();
 }
 
+bool
+HostPopulateImportMeta(JSContext* aCx, JS::Handle<JSObject*> aModule,
+                       JS::Handle<JSObject*> aMetaObject)
+{
+  MOZ_DIAGNOSTIC_ASSERT(aModule);
+
+  JS::Value value = JS::GetModuleHostDefinedField(aModule);
+  if (value.isUndefined()) {
+    JS_ReportErrorASCII(aCx, "Module script not found");
+    return false;
+  }
+
+  auto script = static_cast<ModuleScript*>(value.toPrivate());
+  MOZ_DIAGNOSTIC_ASSERT(script->ModuleRecord() == aModule);
+
+  nsAutoCString url;
+  MOZ_DIAGNOSTIC_ASSERT(script->BaseURL());
+  MOZ_ALWAYS_SUCCEEDS(script->BaseURL()->GetAsciiSpec(url));
+
+  JS::Rooted<JSString*> urlString(aCx, JS_NewStringCopyZ(aCx, url.get()));
+  if (!urlString) {
+    JS_ReportOutOfMemory(aCx);
+    return false;
+  }
+
+  return JS_DefineProperty(aCx, aMetaObject, "url", urlString, JSPROP_ENUMERATE);
+}
+
 static void
 EnsureModuleResolveHook(JSContext* aCx)
 {
@@ -794,6 +822,7 @@ EnsureModuleResolveHook(JSContext* aCx)
   }
 
   JS::SetModuleResolveHook(rt, HostResolveImportedModule);
+  JS::SetModuleMetadataHook(rt, HostPopulateImportMeta);
 }
 
 void

testing/web-platform/meta/html/semantics/scripting-1/the-script-element/module/import-meta/import-meta-url.html.ini

@@ -1,4 +0,0 @@
-[import-meta-url.html]
-  [Untitled]
-    expected: FAIL
-

testing/web-platform/tests/html/semantics/scripting-1/the-script-element/module/import-meta/import-meta-url.html

@@ -21,6 +21,27 @@ test(() => {
                 base + "/import-meta-dependent.js");
 }, "import.meta.url in a dependent external script");
 
+test(() => {
+  assert_equals(typeof importMetaOnRootModule, "object");
+  assert_not_equals(importMetaOnRootModule, null);
+}, "import.meta is an object");
+
+test(() => {
+  importMetaOnRootModule.newProperty = 1;
+  assert_true(Object.isExtensible(importMetaOnRootModule));
+}, "import.meta is extensible");
+
+test(() => {
+  let names = new Set(Reflect.ownKeys(importMetaOnRootModule));
+  for (name of names) {
+    var desc = Object.getOwnPropertyDescriptor(importMetaOnRootModule, name);
+    assert_equals(desc.writable, true);
+    assert_equals(desc.enumerable, true);
+    assert_equals(desc.configurable, true);
+  }
+}, "import.meta's properties are writable, configurable, and enumerable");
+
+
 import { importMetaOnRootModule as hashedImportMetaOnRootModule1,
          importMetaOnDependentModule as hashedImportMetaOnDependentModule1 }
        from "./import-meta-root.js#1";