feat(utils): add createCooldown util

packages/utils/src/createCooldown.ts

@@ -0,0 +1,15 @@
+/**
+ * Function returned by `createCooldown` returns `true` only when previous `true` was returned
+ * `cooldownMs` or more millis ago, and `false` otherwise. First call always returns `true`.
+ */
+export const createCooldown = (cooldownMs: number) => {
+    let last = 0;
+    return () => {
+        const now = Date.now();
+        if (now - last >= cooldownMs) {
+            last = now;
+            return true;
+        }
+        return false;
+    };
+};

packages/utils/src/index.ts

@@ -7,6 +7,7 @@ export * from './bytesToHumanReadable';
 export * from './capitalizeFirstLetter';
 export * from './cloneObject';
 export * from './countBytesInString';
+export * from './createCooldown';
 export * from './createDeferred';
 export * from './createTimeoutPromise';
 export * as enumUtils from './enumUtils';

packages/utils/tests/createCooldown.test.ts

@@ -0,0 +1,14 @@
+import { createCooldown } from '../src/createCooldown';
+import { createTimeoutPromise } from '../src/createTimeoutPromise';
+
+it('createCooldown', async () => {
+    const cooldown = createCooldown(20);
+    expect(cooldown()).toBe(true);
+    expect(cooldown()).toBe(false);
+    await createTimeoutPromise(10);
+    expect(cooldown()).toBe(false);
+    await createTimeoutPromise(15);
+    expect(cooldown()).toBe(true);
+    await createTimeoutPromise(5);
+    expect(cooldown()).toBe(false);
+});

packages/utils/tests/scheduleAction.test.ts

@@ -151,7 +151,7 @@ describe('scheduleAction', () => {
 
     it('variable timeouts', async () => {
         const TIMEOUTS = [50, 150, 100];
-        const MARGIN = 5;
+        const MARGIN = 10;
 
         const times: number[] = [Date.now()];
         const action = (signal?: AbortSignal) => {