Compiled Learning Objectives

At the end of the sprint, you should be able to do the following things. Make sure to check you can do them all, and if not, go back and keep practicing until you can.

What is Legacy Code?

• Define legacy code

Understanding Legacy Code

• Define legacy code and its characteristics
• List common challenges when working with legacy code

Fear and logic

• Define and explain Chesterton’s Fence

Finding things

• Use IDE features to navigate an unfamiliar codebase
• Trace a request flow through an application
• Sketch system architecture

Debugging: Proposing and Discarding Hypotheses

• Apply scientific debugging methodology to legacy code
• Formulate and test hypotheses systematically
• Use browser debugging tools effectively with legacy applications

Capturing behaviour in tests

• Describe a feature in terms of its behaviour
• Write a test that captures the behaviour of a feature

Fixing: Targeted Changes with Test Support

• Make a small, targeted fix to legacy code
• Use tests to verify fixes don’t break existing functionality
• Document fixes and their rationale

Extending: Adding Features the Right Way

• Add new features that respect existing patterns
• Extend legacy code without breaking existing functionality
• Follow the design principles of the original codebase
• Use test-driven development for new features

Refining Purple Forest Bugs

• Identify useful elements in a bug report.
• Explain what extra information would help make bug reports more clear.

Discussion: Behavioural Interviews

• Identify preparation and techniques for succeeding at behavioural interviews.