describe('Testing filterArray()', () => {
  it('should filter an array of objects by custom predicates', () => {
    const products = [
      { name: 'A', color: 'Blue', size: 50, locations: ['USA', 'Europe'], details: { length: 20, width: 70 } },
      { name: 'B', color: 'Blue', size: 60, locations: [], details: { length: 20, width: 70 } },
      { name: 'C', color: 'Black', size: 70, locations: ['Japan'], details: { length: 20, width: 71 } },
      { name: 'D', color: 'Green', size: 50, locations: ['USA'], details: { length: 20, width: 71 } },
    ];

    const filters = {
      size: size => size === 50 || size === 70,
      color: color => ['blue', 'black'].includes(color.toLowerCase()),
      locations: locations => locations.find(x => ['JAPAN', 'USA'].includes(x.toUpperCase())),
      details: details => details.length < 30 && details.width >= 70,
    };

    const filtered = filterArray(products, filters);
    const expected = [
      { name: 'A', color: 'Blue', size: 50, locations: ['USA', 'Europe'], details: { length: 20, width: 70 } },
      { name: 'C', color: 'Black', size: 70, locations: ['Japan'], details: { length: 20, width: 71 } },
    ];
    expect(filtered).toStrictEqual(expected);
  });
});