Timeouts for sync config

common/async_util.ts

@@ -0,0 +1,32 @@
+export function throttle(func: () => void, limit: number) {
+  let timer: any = null;
+  return function () {
+    if (!timer) {
+      timer = setTimeout(() => {
+        func();
+        timer = null;
+      }, limit);
+    }
+  };
+}
+
+// race for promises returns first promise that resolves
+export function race<T>(promises: Promise<T>[]): Promise<T> {
+  return new Promise((resolve, reject) => {
+    for (const p of promises) {
+      p.then(resolve, reject);
+    }
+  });
+}
+
+export function timeout(ms: number): Promise<never> {
+  return new Promise((_resolve, reject) =>
+    setTimeout(() => {
+      reject(new Error("timeout"));
+    }, ms)
+  );
+}
+
+export function sleep(ms: number): Promise<void> {
+  return new Promise((resolve) => setTimeout(resolve, ms));
+}