/**
 * utils.ts 单元测试模板
 */

import {
  generateId,
  escapeHTML,
  debounce,
  throttle,
  deepMerge,
  isBrowser,
} from '../src/utils';

describe('generateId', () => {
  test('返回字符串', () => {
    expect(typeof generateId()).toBe('string');
  });

  test('多次调用产生不同值', () => {
    const ids = new Set<string>();
    for (let i = 0; i < 100; i++) ids.add(generateId());
    expect(ids.size).toBe(100);
  });
});

describe('escapeHTML', () => {
  test('转义 < > &', () => {
    const out = escapeHTML('<a>&b</a>');
    expect(out).toContain('&lt;');
    expect(out).toContain('&gt;');
    expect(out).toContain('&amp;');
  });

  test('null/undefined 返回空字符串', () => {
    expect(escapeHTML(null)).toBe('');
    expect(escapeHTML(undefined)).toBe('');
  });
});

describe('debounce', () => {
  test('延迟执行', (done) => {
    let called = 0;
    const fn = debounce(() => { called++; }, 50);
    fn();
    expect(called).toBe(0);
    setTimeout(() => {
      expect(called).toBe(1);
      done();
    }, 100);
  });

  test('多次调用只执行最后一次', (done) => {
    let result = 0;
    const fn = debounce((v: number) => { result = v; }, 50);
    fn(1);
    fn(2);
    fn(3);
    setTimeout(() => {
      expect(result).toBe(3);
      done();
    }, 100);
  });
});

describe('throttle', () => {
  test('首次立即执行', () => {
    let called = 0;
    const fn = throttle(() => { called++; }, 50);
    fn();
    expect(called).toBe(1);
  });

  test('限流期内不重复执行', () => {
    let called = 0;
    const fn = throttle(() => { called++; }, 50);
    fn();
    fn();
    fn();
    expect(called).toBe(1);
  });
});

describe('deepMerge', () => {
  test('浅层合并', () => {
    const out = deepMerge({ a: 1, b: 2 }, { b: 3, c: 4 });
    expect(out).toEqual({ a: 1, b: 3, c: 4 });
  });

  test('深层对象合并', () => {
    const out = deepMerge({ obj: { x: 1 } }, { obj: { y: 2 } });
    expect(out).toEqual({ obj: { x: 1, y: 2 } });
  });
});

describe('isBrowser', () => {
  test('jsdom 环境下返回 true', () => {
    expect(isBrowser()).toBe(true);
  });
});