内置Number对象的覆盖方法在尝试对其执行测试时失败

Number.prototype.toFixed = function(digits) {
    // 自定义逻辑
    return this.toString(); // 示例逻辑，实际应实现具体功能
};

Number.prototype.toFixed = function(digits) {
    return this.toString().slice(0, -digits) + '.' + this.toString().slice(-digits);
}.bind(this);

test('Number.prototype.toFixed should work correctly', () => {
    const num = 123.456;
    expect(num.toFixed(2)).toBe('123.46');
});

// 覆盖Number.prototype.toFixed方法
Number.prototype.toFixed = function(digits) {
    const factor = Math.pow(10, digits);
    return Math.round(this * factor) / factor;
};

// 测试用例
test('Number.prototype.toFixed should work correctly', () => {
    const num = 123.456;
    expect(num.toFixed(2)).toBe('123.46');
    expect(num.toFixed(0)).toBe('123');
    expect(num.toFixed(5)).toBe('123.45600');
});