CEC-5182: add car update status to fleet (#466)

src/utils/polling.js

@@ -0,0 +1,29 @@
+export default class Polling {
+  constructor(callback = () => Promise.resolve(), duration = 1000) {
+    this.callback = callback;
+    this.duration = duration;
+    this.timeout = undefined;
+  }
+
+  #sleep() {
+    this.end();
+    return new Promise((resolve) => {
+      this.timeout = setTimeout(resolve, this.duration);
+    });
+  }
+
+  async start(payload) {
+    this.callback(payload)
+      .then(() => {
+        this.#sleep().then(() => this.start(payload));
+      });
+  }
+
+  end() {
+    if (!this.timeout) {
+      return;
+    }
+
+    clearTimeout(this.timeout);
+  }
+}

src/utils/polling.test.js

@@ -0,0 +1,31 @@
+import Polling from "./polling";
+
+function sleep(ms) {
+  return new Promise(resolve => setTimeout(resolve, ms));
+}
+
+describe("Polling", () => {
+  beforeEach(() => {
+    jest.clearAllMocks();
+  });
+
+  it("starts and ends polling", async () => {
+    const callback = () => Promise.resolve();
+    const poll = new Polling(callback, 100);
+    const spy = jest.spyOn(poll, "callback");
+    poll.start();
+    await sleep(500);
+    poll.end();
+    await sleep(500);
+    expect(spy).toHaveBeenCalledTimes(5);
+  });
+
+  it("async polling", async () => {
+    const callback = () => sleep(100);
+    const poll = new Polling(callback, 100);
+    const spy = jest.spyOn(poll, "callback");
+    poll.start();
+    await sleep(1000);
+    expect(spy).toHaveBeenCalledTimes(5);
+  });
+});