Test automation tutorials, frameworks, and tools — from first scripts to full CI/CD pipelines.
Test Automation
SMTP testing validates that your application correctly constructs and sends emails through an SMTP server. The strategy differs based on what you're testing: unit tests mock the transport, integration tests use a fake SMTP server. Two Levels of Email Tests Unit tests verify email construction — subject, body, recipients,
Test Automation
Sidekiq is the standard background job processor for Ruby/Rails. Its built-in testing support includes fake queues, inline execution, and RSpec matchers that make worker testing straightforward. Testing Modes Sidekiq provides three testing modes via sidekiq/testing: Mode Behavior Sidekiq::Testing.fake! Jobs enqueued but not executed (default for tests)
Test Automation
Billing is the highest-stakes area of a SaaS application. Bugs here cost real money — charging the wrong amount, failing to cancel subscriptions, missing usage records, or double-billing. Testing billing requires testing the logic layer (unit tests), the webhook handlers (integration tests), and the full lifecycle end-to-end. Billing Testing Layers Unit
Test Automation
Role-based access control (RBAC) defines what each user role can do. Testing RBAC means verifying not just that permitted actions work, but that forbidden ones are properly blocked — including attempts to escalate privileges. The Permission Matrix Start by mapping every resource and action to allowed roles: const PERMISSIONS = { projects: { list:
Test Automation
Multi-tenant SaaS applications share infrastructure across customers while keeping their data completely isolated. The testing challenge is proving that isolation works: tenant A cannot read, write, or affect tenant B's data, regardless of how they try. The Core Risk Cross-tenant data leakage is the most critical bug class
Test Automation
Test fixtures for multi-tenant applications need to create data within specific tenant contexts and clean up completely between tests. Poorly managed fixtures are the number one cause of flaky tests in multi-tenant systems — data from one test bleeding into another. The Problem with Naive Fixtures // ❌ Bad: no tenant isolation in
Test Automation
Mailtrap is a cloud-based email testing service that captures emails sent from your application and exposes them via a web UI and REST API. Unlike self-hosted tools, Mailtrap handles the SMTP infrastructure for you. How Mailtrap Works Mailtrap provides a sandbox SMTP server. Configure your application to send emails to
Test Automation
Media-heavy applications — platforms that handle user-uploaded images, videos, audio, or documents — have unique testing requirements. The data is binary, the processing is compute-intensive, and the output quality is hard to assert on with text comparisons. This guide covers the testing strategy across all media types. The Media Testing Stack Browser
Test Automation
Mailpit is a self-hosted email testing tool and SMTP server written in Go. It's the modern replacement for MailHog — actively maintained, faster, and with a cleaner REST API. It captures all outgoing emails from your application and exposes them via a web UI and API. Why Mailpit * Actively
Test Automation
GrowthBook is an open-source feature flagging and A/B testing platform. Its JavaScript SDK is designed to be testable: it accepts forced variations and feature overrides, making unit and integration tests straightforward. SDK Setup npm install @growthbook/growthbook # React npm install @growthbook/growthbook-react Copy Basic Usage // lib/growthbook.js import
Test Automation
MailHog is a self-hosted fake SMTP server written in Go. It captures all outgoing emails and exposes them via a web UI and REST API. It runs as a single binary or Docker container with no configuration required. Installation # Docker (recommended) docker run -d -p 1025:1025 -p 8025:8025
Test Automation
Image processing is a common source of production bugs: wrong dimensions, incorrect formats, quality degradation, metadata exposure (EXIF with GPS coordinates), and broken pipelines. Testing it requires generating test images programmatically and asserting on processed output. Generating Test Images with Sharp Don't commit test images to version control.