javascript - Chai Library 中 equal 和 eql 有什么区别

Question

我有一个关于用于单元测试的 Chai 库的问题。我注意到一条声明说:

• equal : 断言目标严格 (===) 等于给定值。
• eql : 断言目标深度等于值。

我对strictly 和deeply 之间的区别感到困惑。

Answer 1

严格相等(或===)意味着您正在将完全相同对象与其自身进行比较:

var myObj = {
   testProperty: 'testValue'
};
var anotherReference = myObj;

expect(myObj).to.equal(anotherReference); // The same object, only referenced by another variable
expect(myObj).to.not.equal({testProperty: 'testValue'}); // Even though it has the same property and value, it is not exactly the same object

Deeply Equal 另一方面意味着比较对象(以及可能的深层链接对象)的每个属性 都具有相同的值。所以:

var myObject = {
    testProperty: 'testValue',
    deepObj: {
        deepTestProperty: 'deepTestValue'
    }
}
var anotherObject = {
    testProperty: 'testValue',
    deepObj: {
        deepTestProperty: 'deepTestValue'
    }
}
var myOtherReference = myObject;

expect(myObject).to.eql(anotherObject); // is true as all properties are the same, even the inner object (deep) one
expect(myObject).to.eql(myOtherReference) // is still also true for the same reason