Testing Your Integration: Building Reliable Fixtures for Telegram Registration Checks

When integrating with the TG Validator API, your application's resilience depends on how well you handle the boundary between valid, negative, and undetermined states. As noted in Invariants are cheap. Silent corruption is not., failing to validate data at the integration layer often leads to silent failures that are difficult to debug later.

Because the TG Validator API is synchronous—returning results in the same HTTP response—your test suite must precisely mock these outcomes to ensure your CRM or notification service behaves correctly.

Understanding the Integration Boundary

The API provides a registered boolean in the response data for all successful checks. However, a robust integration must account for cases where a check cannot be decided. In such instances, the API returns a non-zero business code rather than a completed result object. Treating these undetermined states as "unregistered" can lead to incorrect business logic, such as prematurely discarding valid leads or failing to trigger necessary retries.

Stage 1: Define Your Mock Fixtures

To ensure your service handles these states correctly, create three distinct test fixtures. These should represent the full range of responses your application will encounter.

1. The Success Fixture (Registered)

This fixture confirms a positive registration signal. Ensure your internal logic maps the registered: true state to your "reachable" status.

2. The Negative Fixture (Not Registered)

This fixture confirms the number exists but is not currently registered on Telegram. Your logic should treat registered: false as a "not reachable" status.

3. The Undetermined Fixture (Non-Zero Business Code)

This is the most critical fixture for stability. When the API returns a non-zero business code, it indicates the check could not be completed. Your application should be configured to handle this as an "undetermined" state, triggering a retry or flagging the record for manual review, rather than assuming the number is unregistered.

Stage 2: Implementing the Adapter Pattern

When writing your integration layer, encapsulate the API response parsing. This keeps your business logic clean and allows you to swap real API calls for your test fixtures during local development.

// Conceptual: Normalizing the API response
function processApiResponse(apiResponse) {
 // Check for business code first
 if (apiResponse.code !== 0) {
 return { status: 'undetermined', reason: apiResponse.msg };
 }

 // Handle the registered boolean
 return {
 status: apiResponse.data.registered ? 'reachable' : 'unreachable'
 };
}

Stage 3: Testing for Concurrency and Timeouts

TG Validator enforces per-user concurrency and timeout controls. Your test suite should also simulate these scenarios by ensuring your client-side code correctly catches these specific error codes. By testing how your application reacts when a concurrency slot is occupied or a request times out, you prevent your system from crashing under load.

Conclusion

By treating your API response fixtures as a contract, you protect your application from silent data corruption. Always verify that your code distinguishes between a definitive registered: false result and an undetermined state caused by a non-zero business code. For more details on error codes and concurrency limits, consult the official API documentation.

This article was drafted with AI assistance and reviewed before publishing.