Migrate e2e tests to TypeScript

e2e/eventually.ts

@@ -0,0 +1,30 @@
+const defaultInterval = 100;
+const defaultTimeout = 2000;
+
+type Handler = () => void
+
+const sleep = (ms: number): Promise<void> => {
+  return new Promise(resolve => setTimeout(resolve, ms));
+}
+ 
+const eventually = async (
+  fn: Handler,
+  timeout = defaultTimeout,
+  interval = defaultInterval,
+): Promise<void> => {
+  let start = Date.now();
+  let loop = async() => {
+    try {
+      await fn();
+    } catch (err) {
+      if (Date.now() - start > timeout) {
+        throw err;
+      }
+      await sleep(interval);
+      await loop();
+    }
+  };
+  await loop();
+};
+
+export default eventually;