fix: add missing available plugins to babel-preset-env-standalone

packages/babel-preset-env-standalone/package.json

@@ -14,10 +14,13 @@
   "devDependencies": {
     "@babel/plugin-proposal-dynamic-import": "^7.7.0",
     "@babel/plugin-proposal-json-strings": "^7.0.0",
+    "@babel/plugin-syntax-json-strings": "^7.2.0",
+    "@babel/plugin-syntax-top-level-await": "^7.7.0",
     "@babel/plugin-transform-named-capturing-groups-regex": "^7.7.0",
     "@babel/plugin-transform-new-target": "^7.4.4",
     "@babel/preset-env": "^7.7.1",
-    "@babel/standalone": "^7.7.3"
+    "@babel/standalone": "^7.7.3",
+    "lodash": "^4.17.13"
   },
   "keywords": [
     "babel",

packages/babel-preset-env-standalone/src/available-plugins.js

@@ -5,6 +5,8 @@ const notIncludedPlugins = {
   "transform-new-target": require("@babel/plugin-transform-new-target"),
   "proposal-json-strings": require("@babel/plugin-proposal-json-strings"),
   "proposal-dynamic-import": require("@babel/plugin-proposal-dynamic-import"),
+  "syntax-json-strings": require("@babel/plugin-syntax-json-strings"),
+  "syntax-top-level-await": require("@babel/plugin-syntax-top-level-await"),
 };
 
 Object.keys(notIncludedPlugins).forEach(pluginName => {

packages/babel-preset-env-standalone/test/available-plugins.js

@@ -0,0 +1,14 @@
+import expectedAvailablePlugins from "@babel/preset-env/lib/available-plugins";
+import actualAvailablePlugins from "../lib/available-plugins";
+import difference from "lodash/difference";
+describe("available-plugins", () => {
+  it("should be a superset of available-plugins in @babel/preset-env", () => {
+    const expectedPluginList = Object.keys(expectedAvailablePlugins);
+    expectedPluginList.sort();
+
+    const actualPluginList = Object.keys(actualAvailablePlugins);
+    actualPluginList.sort();
+    // If this test is failed, add the missing plugins to ./src/available-plugins
+    expect(difference(expectedPluginList, actualPluginList)).toEqual([]);
+  });
+});