Why chaining simulates real workflows in Postman - Automation Benefits in Action

Automate API request chaining to simulate real workflows

Preconditions (3)

Step 1: Send a POST request to create a new user with valid data

Step 2: Extract the user ID from the create user response

Step 3: Send a GET request to retrieve the user details using the extracted user ID

Step 4: Verify the user details response contains the correct user information

✅ Expected Result: The GET request returns user details matching the created user, confirming chaining simulates real workflows

Automation Requirements - Postman Tests (JavaScript)

Assertions Needed:

Verify POST response status is 201

Verify user ID is extracted and not null

Verify GET response status is 200

Verify GET response body contains expected user data

Best Practices:

Use pm.sendRequest for chaining requests

Use pm.expect for assertions

Extract variables using pm.response.json()

Keep tests readable and maintainable

Automated Solution

Postman

pm.test('Create user and chain to get user details', function () {
    pm.sendRequest({
        url: 'https://api.example.com/users',
        method: 'POST',
        header: {
            'Content-Type': 'application/json'
        },
        body: {
            mode: 'raw',
            raw: JSON.stringify({ name: 'John Doe', email: '[e-mail]' })
        }
    }, function (err, res) {
        pm.expect(err).to.be.null;
        pm.expect(res).to.have.property('code', 201);
        const userId = res.json().id;
        pm.expect(userId).to.be.a('string').that.is.not.empty;

        pm.sendRequest({
            url: `https://api.example.com/users/${userId}`,
            method: 'GET'
        }, function (err2, res2) {
            pm.expect(err2).to.be.null;
            pm.expect(res2).to.have.property('code', 200);
            const user = res2.json();
            pm.expect(user).to.have.property('name', 'John Doe');
            pm.expect(user).to.have.property('email', '[e-mail]');
        });
    });
});

This test script uses Postman’s pm.sendRequest to chain two API calls, simulating a real workflow.

First, it sends a POST request to create a user and checks the response status is 201 (Created).

Then, it extracts the id from the response JSON and verifies it is a non-empty string.

Next, it sends a GET request using the extracted id to retrieve user details.

Finally, it asserts the GET response status is 200 (OK) and the returned user data matches the created user.

This chaining simulates how real applications use data from one API call in the next, ensuring workflows are tested end-to-end.

Common Mistakes - 3 Pitfalls

Not waiting for the first request to complete before sending the second

Hardcoding user ID instead of extracting from response

Not checking response status codes before proceeding

Bonus Challenge

Now add data-driven testing with 3 different user data inputs for creation and verify each workflow

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