Token management in variables in Postman - Test Execution Trace

Test Overview

This test automates the process of obtaining an authentication token from an API and storing it in a Postman environment variable. It then verifies that the token is correctly saved for use in subsequent requests.

Test Code - Postman Tests

Postman

pm.test("Get Auth Token and save to environment variable", function () {
    pm.sendRequest({
        url: pm.environment.get("auth_url"),
        method: 'POST',
        header: {
            'Content-Type': 'application/json'
        },
        body: {
            mode: 'raw',
            raw: JSON.stringify({
                username: pm.environment.get("username"),
                password: pm.environment.get("password")
            })
        }
    }, function (err, res) {
        pm.expect(err).to.equal(null);
        pm.expect(res).to.have.property('code', 200);
        const jsonData = res.json();
        pm.expect(jsonData).to.have.property('token');
        pm.environment.set("auth_token", jsonData.token);
        pm.expect(pm.environment.get("auth_token")).to.be.a('string').and.not.empty;
    });
});

Execution Trace - 4 Steps

Step	Action	System State	Assertion	Result
1	Test starts and sends POST request to authentication URL with username and password from environment variables	Postman sends HTTP POST request to the API endpoint defined in 'auth_url' environment variable with JSON body containing username and password	-	PASS
2	Receives response from API	API responds with HTTP status code 200 and JSON body containing a 'token' field	Check that error is null and response code is 200	PASS
3	Parse JSON response and verify 'token' field exists	Response JSON parsed successfully and contains 'token' key	Assert that 'token' property exists in response JSON	PASS
4	Save the token value to environment variable 'auth_token'	Environment variable 'auth_token' is set with the token string	Verify 'auth_token' environment variable is a non-empty string	PASS

Failure Scenario

Failing Condition: API returns error or no token in response, or environment variable fails to set

Execution Trace Quiz - 3 Questions

What does the test verify immediately after receiving the API response?

A That the response status code is 200 and there is no error

B That the token is saved in local storage

C That the username and password are correct

D That the environment variable 'auth_url' is set

Key Result

Always verify that tokens received from authentication APIs are correctly saved in environment variables for reuse in subsequent API calls. This ensures smooth and secure token management in automated tests.