jinshen-website/server/utils/object.test.ts

import { expect, test, describe } from 'vitest';

/**
 * 单元测试: isObject
 */
describe('isObject', () => {
  test('identify plain object', () => {
    expect(isObject({})).toBe(true);
    expect(isObject({ key: 'value' })).toBe(true);
  });
  test('identify null as non objevt', () => {
    expect(isObject(null)).toBe(false);
  });
  test('identify non-object types', () => {
    expect(isObject(undefined)).toBe(false);
    expect(isObject(42)).toBe(false);
    expect(isObject('string')).toBe(false);
    expect(isObject(Symbol('sym'))).toBe(false);
    expect(isObject(true)).toBe(false);
    expect(isObject(() => {})).toBe(false);
  });
  test('identify arrays as objects', () => {
    expect(isObject([])).toBe(true);
  });
  test('identify narrowed object type', () => {
    const value: unknown = { id: 1 };
    if (isObject<{ id: number }>(value)) {
      expect(value.id).toBe(1);
    } else {
      throw new Error('Type narrowing failed');
    }
  });
});

/**
 * 单元测试: isArrayOfObject
 */
describe('isArrayOfObject', () => {
  test('identify array of plain objects', () => {
    const arr = [{ id: 1 }, { name: 'Alice' }];
    expect(isArrayOfObject<{ id?: number; name?: string }>(arr)).toBe(true);
  });
  test('identify array containing non-objects', () => {
    expect(isArrayOfObject([1, 2, 3])).toBe(false);
    expect(isArrayOfObject([{ id: 1 }, null])).toBe(false);
    expect(isArrayOfObject([{ id: 1 }, 'string'])).toBe(false);
  });
  test('identify non-array types', () => {
    expect(isArrayOfObject(null)).toBe(false);
    expect(isArrayOfObject({})).toBe(false);
    expect(isArrayOfObject(42)).toBe(false);
  });
  test('identify empty array as array of objects', () => {
    expect(isArrayOfObject([])).toBe(true);
  });
  test('identify narrowed array of object type', () => {
    const data: unknown = [{ id: 1 }, { id: 2 }];
    if (isArrayOfObject<{ id: number }>(data)) {
      // TS 能识别为 { id: number }[]
      expect(data[0].id).toBe(1);
      expect(data[1].id).toBe(2);
    } else {
      throw new Error('Type guard failed');
    }
  });
});