Check property of a nested element - Postman test

Question

Please assist in getting the property type of a nested element from a JSON response in postman. Below is my response after doing a POST.

{
    "MyList": [
        [
            {
                "id": 1,
                "name": "Test"
            }
        ]
    ]
}

I would like to check the name and id properties if they are of type number and string. Below is my code but getting error : Cannot read property '0' of undefined.

 pm.test("Check schema and datatype", () =>{
    var jsonData = pm.response.json();

    pm.expect(typeof(jsonData[0].id)).to.eql('number');
    pm.expect(typeof(jsonData[0].name)).to.eql('string');
 })

Answer 1

Although your response body looks a little strange to me, you could create a test to check those data types like this:

pm.test("Check schema and datatype", () => {
    let jsonData = pm.response.json();

    pm.expect(jsonData.MyList[0][0].id).to.be.a('number');
    pm.expect(jsonData.MyList[0][0].name).to.be.a('string');
})

This is using the chai a method:

https://www.chaijs.com/api/bdd/#method_a

EDIT

To check the size or number of objects in the array, you can use this:

pm.test("Verify number of records returned", () => { 
    let jsonData = pm.response.json().MyList[0]
    pm.expect(jsonData.length).to.equal(1);
});