Testing & Refactoring

Overview

Devin can analyze existing codebases, identify areas for improvement, or execute on refactoring requirements you share without breaking functionality.

Common Use Cases

Writing and expanding test coverage
Code refactoring and optimization
API endpoint development and modification
Performance improvements
Code review and quality assurance
Automated testing workflows via the API Reference

Example Prompts

Write unit test

Can you get https://github.com/markedjs/marked set up, use the command line tool with the --output/-o flag, then add a unit test to test the --output flag?
There should already be similar tests in bin.test.js that you can add to.

Endpoint refactor

Currently when users sends a POST to <endpoint>, we <describe endpoint behavior>. It would be better to split this endpoint into 2 separate endpoints because <explain reasoning>.
<Describe what the first endpoint should do>.
<Describe what the second endpoint should do>.
Test by <explain how Devin can test each endpoint to verify it's on the right track>.

General refactor

Example Sessions

Code Coverage Tutorial

Learn how to improve test coverage systematically through our detailed tutorial:

Writing comprehensive unit tests
Identifying coverage gaps
Implementing missing test cases

View the Code Coverage Tutorial

Connect4 Code Refactor

A complete refactoring session showing:

Code structure improvement
Component separation
Performance optimization
Test coverage enhancement

View Session: https://app.devin.ai/sessions/8965de5e3ae0436985bf3dd2e1a5b4af

Prompts

Tutorials

​Overview

​Common Use Cases

​Example Prompts

​Example Sessions

​Code Coverage Tutorial