API integration testing: validate multi-endpoint workflows

What is integration testing?

Integration testing verifies that multiple components work together correctly. For APIs, this means testing **complete user workflows** that span multiple endpoints, ensuring data flows correctly between them.

Example: E-commerce checkout flow

• 1. POST /auth/login → Get auth token
• 2. POST /cart/add → Add product (use token from step 1)
• 3. GET /cart → Verify product in cart
• 4. POST /checkout → Complete purchase
• 5. GET /orders/:id → Confirm order created

If any step fails or data doesn't pass correctly between steps, the integration test fails.

Why integration testing matters

Individual endpoints might work perfectly in isolation, but fail when chained together. Integration tests catch:

• State management bugs: Session expires between steps
• Data consistency issues: User created in step 1 doesn't exist in step 2
• Authorization failures: Token from login not accepted by other endpoints
• Race conditions: Async operations complete out of order
• Database transaction failures: Partial commits leave data in broken state

How to run integration tests in Flasqo

1. Navigate to Integration Testing
   Go to Testing Types → Integration Testing → Launch
2. Create a test scenario
   Click "New Scenario" and name it (e.g., "User Signup to First Purchase")
3. Add first endpoint
   • Endpoint: POST /auth/signup
   • Body: {"email": "test@example.com", "password": "SecurePass123"}
   • Extract: user_id from response
4. Chain second endpoint
   Click "+ Add Step"
   • Endpoint: POST /auth/login
   • Body: {"email": "test@example.com", "password": "SecurePass123"}
   • Extract: auth_token from response
5. Continue chaining
   Add more steps, using extracted values:
   • Use {{auth_token}} in Authorization header
   • Use {{user_id}} in request body
   Flasqo auto-populates variables from previous steps
6. Add assertions
   For each step, validate:
   • Status code = 200
   • Response contains expected fields
   • Values match expectations
7. Run scenario
   Click "Run Integration Test"
   Flasqo executes steps sequentially and reports which step failed (if any)

Common integration test scenarios

User lifecycle

Signup → Email verification → Login → Update profile → Delete account

E-commerce flow

Browse products → Add to cart → Apply coupon → Checkout → Payment → Order confirmation

Content management

Create draft → Add media → Publish → Edit → Unpublish → Delete

Multi-user collaboration

User A creates document → User A shares with User B → User B edits → User A views changes

Best practices

1. Test realistic user journeys

Don't test random endpoint combinations. Focus on actual workflows users perform.

2. Clean up test data

Add final step to delete created resources. Prevents test data pollution.

3. Test both happy and sad paths

What happens if step 3 fails? Does the system rollback step 1 and 2?

4. Run in isolated test environment

Use test database, not production. Integration tests create/modify data.