TDD in Legacy Code Outline

Legend

• ✅ Practical hands-on work (mandatory) - this includes Sandbox Project Tasks

• 📖 Supplementary reading (optional) - theory, concepts - you can read later

Foundations

Test Pyramid

• 📖 Old Test Pyramid

• 📖 Modern Test Pyramid

• 📖 Modern Test Pyramid - Illustrated

• 📖 Modern Test Pyramid - System Level

• 📖 Modern Test Pyramid - Component Level

• 📖 Modern Test Pyramid - Unit Level

TDD

• 📖 TDD Cycles

• 📖 Modern TDD

• 📖 Modern TDD - System Level

• 📖 Modern TDD - Component Level

• 📖 Modern TDD - Unit Level

Pipeline

• 📖 Modern Pipeline

• 📖 Modern Pipeline - Commit Stage

• 📖 Modern Pipeline - Acceptance Stage

• 📖 Modern Pipeline - Release Stage

Setup Instructions

• ✅ Sandbox Project Setup

• 📖 Untestable Architecture

Phase 1. Pipeline in Legacy Code

• ✅ Commit Stage

• ✅ Acceptance Stage

• ✅ Release Stage

• 🎯 Pipeline (Summary)

Phase 2. Acceptance Test Driven Development (ATDD) in Legacy Code

Smoke Tests

• ✅ E2E Testable Architecture

• 📖 Smoke Tests (Concepts)

• ✅ Smoke Tests

E2E Tests

• ✅ E2E Tests

• 📖 E2E Tests (Concepts)

• ✅ Maintainable E2E Tests

Acceptance Tests & External System Contract Tests

• ✅ Acceptance Testable Architecture

• ✅ Acceptance Tests

• 📖 Acceptance Tests (Concepts)

• ✅ Maintainable Acceptance Tests

• ✅ External System Contract Tests

• 📖 External System Contract Tests (Concepts)

• ✅ Maintainable External System Contract Tests

• 🎯Acceptance Tests & External System Contract Tests (Summary)

Acceptance Test Driven Development (ATDD)

• ✅ Backlog Refinement

• ✅ ATDD - User Stories

• ✅ ATDD - User Stories - System DSL

• ✅ ATDD - User Stories - External System DSL

• ✅ ATDD - Bugs

• ✅ ATDD - System UI Redesign

• ✅ ATDD - System API Redesign

• ✅ ATDD - External System API Changes

Further work on Legacy Code

• ✅ Comprehensive Acceptance Tests

• ✅ Comprehensive External System Contract Tests

Phase 3. Component Test Driven Development (CTDD) in Legacy Code

Component Tests & Contract Tests

• ✅ Component Testable Architecture

• ✅ Component Tests - Frontend

• ✅ Component Tests - Backend

• ✅ Maintainable Component Tests - Frontend

• ✅ Maintainable Component Tests - Backend

• ✅ Contract Tests

• ✅ Maintainable Contract Tests

Component Test Driven Development (CTDD)

• ✅ Component Test Driven Development (CTDD)

Phase 4. Test Driven Development (TDD) in Legacy Code

• ✅ Hexagonal Architecture

• ✅ Unit Testing

• ✅ Narrow Integration Testing

• ✅ Test Driven Development (TDD)

• ✅ Code Coverage & Mutation Testing

• ✅ Static Code Analysis

Disclaimer: The series outline above is a rough draft. As I write the articles, I may update the outline (and may take into account reader feedback and questions).

Learn in practice

As a Premium Member, I will support you every step of the way.

This Series will provide you with rough guidance. However, as you try to apply it to your project, you may face additional challenges due to real-life complexities.

As a Premium Subscriber, I’ll be your mentor. As you read the series and try some steps, as you face roadblocks or challenges, you can ask me any questions by commenting on the article. Comments are only available to Premium Subscribers.

TDD in Legacy Code - Get Access

You tried TDD in your real-life project, but it didn’t work. You don’t want to waste years with trial-and-error. You don’t want to read hundreds of pages of books. That’s why I made the TDD in Legacy Code series:

✔ Step-by-step guide in introducing TDD to Legacy Code

✔ Applying the TDD transformation to Legacy Microservice Architecture

✔ Ask me questions about the challenges you face applying TDD in Legacy Code

1. 🔒Upgrade to premium (annual/monthly) plan to read the TDD in Legacy Code Series, comment and ask questions

2. If you want to take it to the next level, get my support as you’re implementing, then you can join the Optivem Circle (Annual Membership) to get access to the sandbox review.

Upgraded version: AI-assisted ATDD

Given the rise of AI, I’m also offering an AI-upgraded version. This is currently available only to limited people. Send me a DM for more info.