Integration Tester

Integration Tester

Produce a complete integration test plan for a system integration. This covers sandbox environment setup, contract testing, functional test cases, end-to-end scenarios, and the regression suite. The test plan must be specific enough that a QA engineer can execute it without clarification.

Test Scope and Strategy

Define what is being tested and what is out of scope:

In scope:

• API connector: authentication, endpoint calls, request formation, response parsing
• Data mapping: field transformations, lookup table translations, null handling
• Error handling: retry behavior, DLQ routing, alert triggering
• End-to-end flow: source record change → integration processing → destination record created/updated

Out of scope:

• Source system business logic (tested by source system owner)
• Destination system business logic (tested by destination system owner)
• Network infrastructure performance
• Load/performance testing (separate engagement if required)

Test environments:

Mock Server Design

For source or destination systems without a sandbox, build a mock server.

Mock server tool selection: WireMock (Java), Nock (Node.js), or MockServer (Docker). Choose based on the team's language stack.

Mock endpoint definitions:

For each API endpoint, define a mock that returns realistic test data:

GET /policies?status=active&limit=100
Response 200:
{
  "data": [
    {
      "policy_id": "test-policy-001",
      "policy_number": "TEST-POL-2026-001",
      "client_id": "client-001",
      "effective_date": "2026-01-15",
      "premium_amount": 1250.00,
      "status_code": "A",
      "lob_code": "AU",
      "producer_npi": "1234567890",
      "notes": "Test policy for integration testing",
      "created_at": "2026-01-15T09:00:00-05:00",
      "modified_at": "2026-01-15T09:00:00-05:00"
    }
  ],
  "next_page_token": null,
  "has_more": false
}

Error scenario mocks:

Contract Tests

Contract tests verify the integration assumes the correct API shape. Run against both the mock and the real sandbox.

Contract test suite:

describe('Source API Contract', () => {
  describe('GET /policies', () => {
    it('returns array in data field', async () => {
      const response = await apiClient.getPolicies();
      expect(Array.isArray(response.data)).toBe(true);
    });
    
    it('policy has required fields', async () => {
      const response = await apiClient.getPolicies({ limit: 1 });
      const policy = response.data[0];
      expect(policy).toHaveProperty('policy_id');
      expect(policy).toHaveProperty('policy_number');
      expect(policy).toHaveProperty('client_id');
      expect(policy).toHaveProperty('effective_date');
      expect(policy).toHaveProperty('premium_amount');
      expect(policy).toHaveProperty('status_code');
      expect(policy).toHaveProperty('lob_code');
    });
    
    it('effective_date is ISO 8601 date format', async () => {
      const response = await apiClient.getPolicies({ limit: 1 });
      const date = response.data[0].effective_date;
      expect(date).toMatch(/^\d{4}-\d{2}-\d{2}$/);
    });
    
    it('premium_amount is a number', async () => {
      const response = await apiClient.getPolicies({ limit: 1 });
      expect(typeof response.data[0].premium_amount).toBe('number');
    });
    
    it('pagination: next_page_token present when has_more is true', async () => {
      // Only meaningful if source has > limit records
      const response = await apiClient.getPolicies({ limit: 1 });
      if (response.has_more) {
        expect(response.next_page_token).toBeTruthy();
      }
    });
  });
  
  describe('Authentication', () => {
    it('returns 401 with invalid credentials', async () => {
      const badClient = createApiClient({ apiKey: 'invalid-key' });
      await expect(badClient.getPolicies()).rejects.toThrow(/401/);
    });
    
    it('token is refreshed before expiry', async () => {
      // Set token to expire in 30 seconds, wait 25 seconds, make a request
      // Verify a new token was acquired without a 401
      // [Implementation specific to auth mechanism]
    });
  });
});

Run contract tests against real sandbox: After running against mocks, run the same contract test suite against the actual sandbox API. Any failure indicates the API has changed from what the integration assumes — fix the integration before proceeding.

Functional Test Cases

Happy path test cases:

Error handling test cases:

End-to-End Test Cases

Test the complete flow from source system change to destination record update:

Regression Test Suite

Automate the happy path and critical error handling tests. Run on every deployment:

Automated regression tests (subset of functional tests that can be automated reliably):

• F-01 through F-05 (field mapping correctness)
• E-01, E-03, E-06 (retry behavior)
• E-05 (duplicate handling)
• E2E-01 (basic end-to-end)

Regression run configuration:

• Trigger: Every deployment to integration test environment (CI/CD pipeline step)
• Environment: Integration test environment with sandbox source and destination
• Duration target: < 10 minutes for the regression suite
• Pass/fail: Any test failure blocks deployment to UAT

Test data management:

• Create test records with IDs in the format TEST-[YYYYMMDD]-[sequence] to distinguish from real data
• Clean up test records after each test run (DELETE test records from sandbox)
• Maintain a fixed set of seed records for tests that require pre-existing data (e.g., producer with known NPI)

Output Format

Deliver as:

1. Test scope and environment table
2. Mock server endpoint definitions (one section per endpoint)
3. Contract test suite (code blocks using the pattern above)
4. Functional test case catalog (complete table — happy path and error cases)
5. End-to-end scenario table
6. Regression suite definition (which tests are automated, run trigger, duration target)
7. Test data management approach (naming convention, cleanup procedure)
8. Go-live testing checklist (what must pass before production deployment: all functional tests, E2E-01, zero DLQ entries in integration test after 24 hours of testing)