Add tests for wait util

Author: kyarik

src/utils/promise/wait/index.test.ts

@@ -0,0 +1,27 @@
+import { wait } from '.';
+
+it('returns a promise that resolves after the specified amount of time', async () => {
+  jest.useFakeTimers();
+
+  let value: number = 1;
+
+  wait(1000).then(() => {
+    value++;
+  });
+
+  expect(value).toBe(1);
+
+  jest.advanceTimersByTime(500);
+
+  await Promise.resolve();
+
+  expect(value).toBe(1);
+
+  jest.advanceTimersByTime(500);
+
+  await Promise.resolve();
+
+  expect(value).toBe(2);
+
+  jest.useRealTimers();
+});

src/utils/promise/wait/index.ts

@@ -2,4 +2,4 @@
  * Returns a promise that resolves after the specified amount of time in milliseconds.
  * @param ms Amount in milliseconds to wait.
  */
-export const wait = (ms: number) => new Promise((res) => setTimeout(res, ms))
+export const wait = (ms: number) => new Promise(res => setTimeout(res, ms));