CEC-4499: add bulk update configs support (#357)

* add taskRunner util

* add bulk update config flow

src/utils/taskRunner.test.js

@@ -0,0 +1,58 @@
+import TaskRunner from "./taskRunner";
+
+const mockPromise = async (id, ms) => {
+  await new Promise(resolve => setTimeout(resolve, ms));
+  return id;
+}
+
+const asyncFn1 = () => mockPromise(1, 200);
+const asyncFn2 = () => mockPromise(2, 100);
+const asyncFn3 = () => mockPromise(3, 50);
+
+describe("TaskRunner", () => {
+  it("runs task added to queue, when space available", () => {
+    const taskRunner = new TaskRunner(2);
+    expect(taskRunner.running).toEqual(0);
+    taskRunner.push(() => mockPromise(1, 300));
+    expect(taskRunner.running).toEqual(1);
+  });
+
+  it("keeps task in queue when at concurrency limit", () => {
+    const taskRunner = new TaskRunner(2);
+    expect(taskRunner.running).toEqual(0);
+    taskRunner.push(() => mockPromise(1, 100));
+    taskRunner.push(() => mockPromise(2, 25));
+    taskRunner.push(() => mockPromise(3, 10));
+    expect(taskRunner.running).toEqual(2);
+    expect(taskRunner.queue.length).toEqual(1);
+  });
+
+  it("runs queued tasks as space becomes available", async () => {
+    const taskRunner = new TaskRunner(2);
+    taskRunner.push(() => mockPromise(1, 600));
+    taskRunner.push(() => mockPromise(2, 300));
+    taskRunner.push(() => mockPromise(3, 100));
+    expect(taskRunner.queue.length).toEqual(1);
+    await new Promise(r => setTimeout(r, 301));
+    expect(taskRunner.queue.length).toEqual(0);
+  });
+
+  it("runs tasks in order", async () => {
+    const actual = [];
+    const taskRunner = new TaskRunner(2);
+    taskRunner.push(asyncFn1)
+      .then((id) => {
+        actual.push(id);
+      });
+    taskRunner.push(asyncFn2)
+      .then((id) => {
+        actual.push(id);
+      });
+    taskRunner.push(asyncFn3)
+      .then((id) => {
+        actual.push(id);
+      });
+      await new Promise(resolve => setTimeout(resolve, 500));
+      expect(actual).toEqual([2, 3, 1]);
+  });
+})