Testing
Every third-party API integration needs tests — but mocking, contract testing, and real integration testing each have different tradeoffs. Mocks are fast but drift from reality. Real integration tests are accurate but slow and expensive. Contract tests are the middle ground that most teams miss. This guide covers when to use
Testing
OAuth2 integrations are painful to test in CI because the authorization code flow requires a browser and human interaction. This guide covers how to test OAuth2 without browser automation: mocking the token exchange, testing the callback handler, validating token storage, testing refresh flows, and running full browser-based auth tests with
Testing
Slack bot testing requires handling signed webhooks, validating Block Kit UI components, testing slash command responses, and simulating event payloads. This guide covers unit testing with mock payloads, integration testing with the Slack SDK's built-in test utilities, and end-to-end testing with Socket Mode. Slack bots have more failure
Testing
SendGrid provides a sandbox mode that validates emails without sending them, dynamic templates you can test independently, and event webhooks for tracking delivery status. This guide covers testing SendGrid integrations at every level: sandbox validation, template rendering, webhook handling, and deliverability simulation. Email bugs are subtle and slow to surface.
Testing
Twilio provides test credentials that accept API calls without sending real messages, specific magic phone numbers for simulating delivery failures, and a webhook testing workflow for voice and SMS. This guide covers unit testing Twilio integrations with mocks, integration testing with test credentials, and testing TwiML responses. Twilio integrations fail
Testing
Stripe provides a test mode with real API behavior, test card numbers for different scenarios, and a CLI for webhook testing. Testing a payment integration requires covering happy-path charges, declined cards, 3D Secure flows, webhook receipt and idempotency, refunds, and subscription lifecycle events. This guide covers all of them. Payment
Tools & Frameworks
Most PHP projects end up with three separate testing tools: PHPUnit for unit tests, something else for HTTP integration, and a browser automation library bolted on for end-to-end scenarios. Each tool has its own configuration format, its own runner, and its own reporting conventions. Codeception was built to fix exactly
Testing
Integration tests in Kotlin Multiplatform verify that your components work together — not just in isolation. The most common integration point is your API layer: the code that talks to a server using Ktor. This guide covers how to integration-test a Ktor-based client across all KMP targets. Why Integration Tests Matter
Testing Tools
Integration tests need real infrastructure — a real Postgres, a real Redis, a real Kafka. The question isn't whether to use Docker, it's how to manage the Docker lifecycle in your tests. Two approaches dominate: Docker Compose for external service management, and Testcontainers for programmatic container lifecycle
Testing
Integration tests live and die by their data. A test that creates an order needs a product to exist. That product needs a category. That category has constraints. Building this state in every test is tedious and produces tests that are tightly coupled to unrelated domain objects. Getting it wrong
Contract Testing
Contract testing and integration testing both verify that services work together correctly. They solve different problems, run at different points in the development cycle, and provide different types of confidence. Understanding when to use each — and how to use them together — is the key to effective microservice testing. What Each
gRPC
Unit tests are fast but incomplete — they mock dependencies that can behave differently in production. Integration tests with Testcontainers close this gap by running real databases, caches, and dependent services in Docker containers that your test starts and manages. For gRPC services, this means testing against real PostgreSQL instead of