Software Engineering

Red-Green-Refactor: Practicing TDD with Kotlin & JUnit

This course focuses on practicing the core TDD workflow: "Red-Green-Refactor." You'll write failing tests (Red), implement code to pass them (Green), and refactor while keeping tests passing (Refactor). No new concepts are introduced—just hands-on practice with various requirements to sharpen your TDD skills.

JUnit

Kotlin

See path

5 lessons

25 practices

3 hours

Course details

Intro to TDD with Kotlin and JUnit

Preview

Correct Discount Application

Zero Discount Handling Task

Decimal Discount Precision Task

Negative Price Handling Task

Discount Calculator Implementation

Previous Course Next Course: Isolating Dependencies using JUnit and Mockito

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I'm really impressed by the AI tutor Cosmo's feedback about my code. It's honestly kind of insane to me that it's so targeted and specific.

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I'm impressed by the quality and can't stop recommending it. It's also a lot of fun!

Francisco Aguilar Meléndez

Data Scientist

+11

From our community

Hear what our customers have to say about CodeSignal Learn

I'm impressed by the quality and can't stop recommending it. It's also a lot of fun!

Francisco Aguilar Meléndez

Data Scientist

+11

I love that it's personalized. When I'm stuck, I don't have to hope my Google searches come out successful. The AI mentor Cosmo knows exactly what I need.

Faith Yim

Software Engineer

+14

It's an amazing product and exceeded my expectations, helping me prepare for my job interviews. Hands-on learning requires you to actually know what you are doing.

Alex Bush

Full Stack Engineer

I'm really impressed by the AI tutor Cosmo's feedback about my code. It's honestly kind of insane to me that it's so targeted and specific.

Abbey Helterbran

Tech consultant

I tried Leetcode but it was too disorganized. CodeSignal covers all the topics I'm interested in and is way more structured.

Jonathan Miller

Senior Machine Learning Engineer

+12

I'm impressed by the quality and can't stop recommending it. It's also a lot of fun!

Francisco Aguilar Meléndez

Data Scientist

+11

Red-Green-Refactor: Practicing TDD with Kotlin & JUnit

Course details

Unit 15 practices38 min

Unit 24 practices32 min

Unit 35 practices38 min

Unit 45 practices38 min

Unit 56 practices44 min

Turn screen time into skills time

Join the 1M+ learners on CodeSignal

From our community

From our community