Add types to scripts and config files (#1277)

Summary:
Pull Request resolved: https://github.com/facebook/yoga/pull/1277

Now that we have some TypeScript infra set up, move scripts (mainly the benchmarking one) and config files to TypeScript.

Starts to move away a bit from the magic globals used in the JS environment.

Reviewed By: yungsters

Differential Revision: D45511176

fbshipit-source-id: 09bb1117a1b331758ed9d210e82d5b250577df81

javascript/tests/tools/globals.ts

@@ -0,0 +1,27 @@
+/**
+ * Copyright (c) Meta Platforms, Inc. and affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+
+import type { Yoga } from "yoga-layout";
+
+declare global {
+  // eslint-disable-next-line no-var
+  var Yoga: Yoga | undefined;
+  // eslint-disable-next-line no-var
+  var YGBENCHMARK: (title: string, fn: () => void) => void;
+}
+
+if (globalThis.Yoga === undefined) {
+  throw new Error('Expected "Yoga" global to be set');
+}
+if (globalThis.YGBENCHMARK === undefined) {
+  throw new Error('Expected "YGBENCHMARK" global to be set');
+}
+
+const yoga = globalThis.Yoga;
+const benchmark = globalThis.YGBENCHMARK;
+
+export { yoga as Yoga, benchmark as YGBENCHMARK };