Workflow sequencing in Postman - Build an Automation Script

Verify API workflow sequencing for user registration and login

Preconditions (3)

Step 1: Send POST request to /register endpoint with valid user data

Step 2: Verify response status code is 201 Created

Step 3: Extract user ID from registration response

Step 4: Send POST request to /login endpoint with registered user credentials

Step 5: Verify response status code is 200 OK

Step 6: Verify response contains authentication token

✅ Expected Result: User registration succeeds with status 201, login succeeds with status 200, and authentication token is returned

Automation Requirements - Postman with JavaScript tests

Assertions Needed:

Status code is 201 for registration

Status code is 200 for login

Authentication token exists in login response

Best Practices:

Use environment variables to store and reuse user ID and token

Use pm.expect assertions for validation

Chain requests using Postman collection runner or scripts

Handle asynchronous requests properly

Automated Solution

Postman

/* Registration Request Test Script */
pm.test("Registration status code is 201", function () {
    pm.response.to.have.status(201);
});

// Save user ID from registration response
const jsonData = pm.response.json();
pm.environment.set("userId", jsonData.id);

/* Login Request Pre-request Script */
// Use stored user credentials
pm.variables.set("email", "[e-mail]");
pm.variables.set("password", "TestPass123");

/* Login Request Test Script */
pm.test("Login status code is 200", function () {
    pm.response.to.have.status(200);
});

pm.test("Authentication token is present", function () {
    const jsonData = pm.response.json();
    pm.expect(jsonData).to.have.property('token');
    pm.environment.set("authToken", jsonData.token);
});

The first part tests the registration response status code is 201, which means the user was created successfully. It extracts the user ID from the JSON response and saves it in an environment variable for reuse.

The login request uses stored user credentials. The test script verifies the login response status code is 200, indicating success, and checks that the response contains an authentication token. The token is saved for future requests.

This approach ensures the workflow sequence is automated: register first, then login using the registered user data. Using environment variables allows data sharing between requests. Assertions with pm.expect validate the expected outcomes.

Common Mistakes - 3 Pitfalls

Not waiting for registration response before sending login request

Hardcoding user data in multiple requests

Not checking response status codes before extracting data

Bonus Challenge

Now add data-driven testing with 3 different user registrations and logins

Show Hint

Practice

1. What is the main purpose of workflow sequencing in Postman?

easy

A. To encrypt API requests for security

B. To create visual charts of API responses

C. To automatically generate API documentation

D. To run multiple requests in a specific order and share data between them

Solution

1. Step 1: Understand workflow sequencing

   Workflow sequencing means running requests one after another in a set order.

2. Step 2: Identify the purpose in Postman

   It allows passing data from one request to the next, making multi-step testing reliable.

3. Final Answer:

   To run multiple requests in a specific order and share data between them -> Option D

4. Quick Check:

   Workflow sequencing = ordered requests with data sharing [OK]

Hint: Think: run requests step-by-step sharing info [OK]

Common Mistakes:

• Confusing workflow sequencing with documentation generation
• Thinking it creates charts or encrypts requests
• Believing requests run randomly without order

2. Which Postman script command is used to call another request inside a test script for workflow sequencing?

easy

A. pm.callRequest()

B. pm.sendRequest()

C. pm.executeRequest()

D. pm.runRequest()

Solution

1. Step 1: Recall Postman scripting commands

   Postman provides a method to send HTTP requests programmatically inside scripts.

2. Step 2: Identify the correct method for calling requests

   The correct method is pm.sendRequest(), which sends a request and handles its response.

3. Final Answer:

   pm.sendRequest() -> Option B

4. Quick Check:

   Call requests inside scripts = pm.sendRequest() [OK]

Hint: Remember: sendRequest sends HTTP calls inside scripts [OK]

Common Mistakes:

• Using non-existent methods like pm.callRequest()
• Confusing with pm.executeRequest() or pm.runRequest() which don't exist
• Misspelling the method name

3. Consider this Postman test script snippet inside Request A:

pm.sendRequest('https://api.example.com/token', (err, res) => {
  pm.environment.set('token', res.json().access_token);
});

What will be the value of token in environment after this runs?

medium

A. The access_token value from the JSON response of the called request

B. Undefined, because pm.sendRequest does not set environment variables

C. An error, because pm.sendRequest cannot be used inside test scripts

D. The entire JSON response as a string

Solution

1. Step 1: Understand pm.sendRequest callback

   The callback receives the response object res, which can be parsed as JSON.

2. Step 2: Extract and set environment variable

   The script sets token to res.json().access_token, which is the access token string from the response.

3. Final Answer:

   The access_token value from the JSON response of the called request -> Option A

4. Quick Check:

   pm.sendRequest sets env var = access_token value [OK]

Hint: pm.sendRequest callback can set env vars from response JSON [OK]

Common Mistakes:

• Assuming pm.sendRequest cannot set variables
• Thinking the whole JSON is stored instead of just access_token
• Confusing asynchronous callback behavior

4. You wrote this Postman test script to run Request B after Request A:

pm.sendRequest('https://api.example.com/data', (err, res) => {
  pm.environment.set('dataId', res.json().id);
});
pm.sendRequest('https://api.example.com/details/{{dataId}}', (err, res) => {
  console.log(res.json());
});

Why might the second request fail or use an empty dataId?

medium

A. Because pm.sendRequest cannot be called twice in the same script

B. Because environment variables cannot be used inside pm.sendRequest URLs

C. Because pm.sendRequest is asynchronous, the second request runs before dataId is set

D. Because console.log is not allowed inside pm.sendRequest callbacks

Solution

1. Step 1: Analyze asynchronous behavior of pm.sendRequest

   pm.sendRequest runs asynchronously, so the second call may start before the first finishes.

2. Step 2: Understand timing of environment variable setting

   The variable dataId is set only after the first request completes, so the second request may see it as empty if it runs too soon.

3. Final Answer:

   Because pm.sendRequest is asynchronous, the second request runs before dataId is set -> Option C

4. Quick Check:

   Async calls need chaining to ensure order [OK]

Hint: Async calls run out of order unless chained properly [OK]

Common Mistakes:

• Thinking environment variables can't be used in URLs
• Believing pm.sendRequest can't be called multiple times
• Assuming console.log is disallowed in callbacks

5. You want to test a multi-step user signup flow in Postman using workflow sequencing. The steps are:
1. Create user (returns userId)
2. Verify email (needs userId)
3. Set user preferences (needs userId)

Which approach correctly sequences these requests and shares userId between them?

hard

A. Use pm.sendRequest inside the test script of each step to call the next, setting environment variables for userId

B. Run all requests manually in any order and copy userId between them

C. Use separate Postman collections for each step without sharing variables

D. Call all requests simultaneously using pm.sendRequest without waiting for responses

Solution

1. Step 1: Understand multi-step flow needs ordered execution

   Each step depends on the previous step's userId, so requests must run one after another.

2. Step 2: Use pm.sendRequest with environment variables to pass data

   Calling the next request inside the previous request's test script and setting userId as an environment variable ensures correct sequencing and data sharing.

3. Final Answer:

   Use pm.sendRequest inside the test script of each step to call the next, setting environment variables for userId -> Option A

4. Quick Check:

   Chain requests with pm.sendRequest and env vars for data flow [OK]

Hint: Chain requests with pm.sendRequest and env vars [OK]

Common Mistakes:

• Running requests manually without automation
• Not sharing variables between requests
• Calling requests simultaneously causing race conditions