Bug 1720570 - Add ModuleType::CSS; r=allstarschh

Differential Revision: https://phabricator.services.mozilla.com/D263409

Author: dminor

js/public/Modules.h

@@ -42,8 +42,9 @@ enum class ModuleType : uint32_t {
   Unknown = 0,
   JavaScript,
   JSON,
+  CSS,
 
-  Limit = JSON,
+  Limit = CSS,
 };
 
 /**

js/src/shell/ModuleLoader.cpp

@@ -547,6 +547,12 @@ JSObject* ModuleLoader::loadAndParse(JSContext* cx, HandleString pathArg,
         return nullptr;
       }
       break;
+    case JS::ModuleType::CSS:
+      // We don't support CSS modules in the shell because we don't have access to a
+      // CSS parser in standalone shell builds.
+      JS_ReportErrorNumberASCII(cx, GetErrorMessage, nullptr,
+                                JSMSG_BAD_MODULE_TYPE);
+      return nullptr;
   }
 
   if (!addModuleToRegistry(cx, moduleType, path, module)) {

js/src/shell/ShellModuleObjectWrapper.cpp

@@ -365,6 +365,9 @@ bool ModuleTypeToString(JSContext* cx, JS::Handle<JSObject*> owner,
     case JS::ModuleType::JSON:
       to.setString(cx->names().json);
       break;
+    case JS::ModuleType::CSS:
+      MOZ_ASSERT_UNREACHABLE("CSS modules are not supported in the shell");
+      break;
   }
 
   MOZ_ASSERT(!to.isUndefined());