How to get the date/time of response in Postman?

Question

I am testing this public API using postman.

When I send a request to this endpoint:

POST: https://reqres.in/api/users

with the following request body:

{
    "name": "Rose Thompson",
    "job": "Senior Markets Agent"
}

I get this as a response:

{
    "name": "Rose Thompson",
    "job": "Senior Markets Agent",
    "id": "818",
    "createdAt": "2022-05-09T09:30:43.839Z"
}

Then I am writing some custom API tests to make sure that the actual and expected responses are the same.

Here is my test code in Postman:

pm.test("Successful POST request", function () {
    pm.expect(pm.response.code).to.be.oneOf([201, 202]);
});

const response = pm.response.json();

pm.test("Should Have Right Name", () => {
    const actual = response.name;
    const expected = "Rose Thompson";

    pm.expect(actual).to.eq(expected);
})

pm.test("Should Have Right Job", () => {
    const actual = response.job;
    const expected = "Senior Markets Agent";

    pm.expect(actual).to.eq(expected);
})

Now I want to write a test for the createdAt field from the response body. I know how to get the actual value from the response itself (I'll do it like this response.createdAt), however, I am having difficulties getting the expected value of the createdAt field.

Can you please tell me how can I get the expected value of the createdAt field?

My suggestion is don't test this field. You can't have exactly expected timestamp. — lucas-nguyen-17, May 09 '22 at 13:36

score 2 · Answer 1 · answered May 09 '22 at 15:39

I would test for this field being present, and not null. If you really want to validate the actual date/time, I would try to avoid the time part, and test for the date.

pm.test("Validate createdAt is present", function () {
    const jsonData = pm.response.json();
    pm.expect(jsonData.createdAt).not.to.be.null;
});

pm.test("Validate createdAt Date", function () {
    const jsonData = pm.response.json();
    const createdAt = jsonData.createdAt;
    const Today = new Date();
    const TodayISO = Today.toISOString().split('T')[0]
    
    // Compare createdAt format for date (substring first 10 characters?)
    pm.expect(createdAt.substr(0,10)).to.equal(TodayISO);
});

The issue here is based on timing. If your tests are running continuously, it is possible for the request/response, and the machine running the tests to cross the date boundary, so the date of the request is technically yesterday when the test codes runs.

Similar to Lucas Nguyen's comment, I would try to avoid testing the actual date if possible, and simply check the field is provided, and not null.

You could, if you wanted to, check the format of the time is correct with something like - `.to.match(/^\d{4}-\d{2}-\d{2}T\d{2}:\d{2}:\d{2}.\d{3}Z$/)` — Danny Dainton, May 10 '22 at 06:45
True. This would check the format to be what is desired, and still skip the actual time check. — Steven Scott, May 11 '22 at 20:54
You could also expand out the format and convert the time into values, and based on the time the request was sent, do math to say the test completed within minutes, or seconds, but this gets considerably more complicated. — Steven Scott, May 11 '22 at 20:55

How to get the date/time of response in Postman?

1 Answers1