import { jest } from '@jest/globals';

import { batchExecute } from './batchExecute';

jest.useFakeTimers();

describe('batchExecute', () => {

let mockExecuteFn: jest.Mock;

beforeEach(() => {

mockExecuteFn = jest.fn();

});

afterEach(() => {

jest.clearAllTimers();

jest.clearAllMocks();

});

it('should process each item in batches of the specified size', async () => {

const items = Array.from({ length: 25 }, (_, i) => i);

const batchSize = 10;

const delayMs = 1000;

batchExecute(items, batchSize, delayMs, mockExecuteFn);

for (let i = 0; i < 2; i++) {

jest.advanceTimersByTime(delayMs);

await Promise.resolve();

}

expect(mockExecuteFn).toHaveBeenCalledTimes(items.length);

items.forEach((item, index) => {

expect(mockExecuteFn).toHaveBeenNthCalledWith(index + 1, item);

});

});

it('should delay between each batch', async () => {

const items = Array.from({ length: 15 }, (_, i) => i);

const batchSize = 5;

const delayMs = 1000;

batchExecute(items, batchSize, delayMs, mockExecuteFn);

expect(mockExecuteFn).toHaveBeenCalledTimes(5);

jest.advanceTimersByTime(delayMs);

await Promise.resolve();

expect(mockExecuteFn).toHaveBeenCalledTimes(10);

jest.advanceTimersByTime(delayMs);

await Promise.resolve();

expect(mockExecuteFn).toHaveBeenCalledTimes(15);

});

it('should handle empty items array without calling executeFn', async () => {

const items: number[] = [];

const batchSize = 10;

const delayMs = 1000;

await batchExecute(items, batchSize, delayMs, mockExecuteFn);

expect(mockExecuteFn).not.toHaveBeenCalled();

});

it('should handle a batch size larger than the number of items', async () => {

const items = [1, 2, 3];

const batchSize = 10;

const delayMs = 1000;

batchExecute(items, batchSize, delayMs, mockExecuteFn);

expect(mockExecuteFn).toHaveBeenCalledTimes(items.length);

items.forEach((item, index) => {

expect(mockExecuteFn).toHaveBeenNthCalledWith(index + 1, item);

});

});

});