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Back-end Engineering

63 learners

Refactoring by Leveraging Tests with Java & JUnit

This course focuses on the Refactor step in TDD, teaching developers to spot code smells and resolve them through refactoring. Using real-world examples, you'll identify common issues, apply refactoring techniques, and ensure functionality is preserved with existing tests.

Java

JUnit

See path

5 lessons

21 practices

3 hours

Computer Science Fundamentals

Lessons and practices

Lesson 1: Eliminating Duplicated Code: Extract Functions and Refactor Magic Numbers

Refactor Duplicate Code in the Tests

Refactor Tests using Parameterization

Extract Function: calculateItemCost

Refactor Duplication between Calculate Functions

Refactor Magic Numbers to Constants

Lesson 2: Refactoring Long Methods with the Extract Method Technique

Extract User Validation

Extracting Validation into Validator Classes

Extract Data Normalization

Focusing on the Data Store

Lesson 3: Long Parameter List: Introduce Parameter Object

Streamline Parameters with a Parameter Object

Introduce a CoursePolicy Parameter Object

Re-order Parameters for Cohesion

Provide Defaults for Most Parameters

Lesson 4: Feature Envy: Move Method Refactoring with TDD

Extract StudentGrade Logic

Refactor: Move Method calculateFinalGrade

Getting rid of the GradeAnalyzer

Eliminate Feature Envy from the Student

Lesson 5: Large Classes: Extract Class Refactoring

Extract a CartItemCollection

Extract a PriceCalculator Class

Refactor ShoppingCart to Use DiscountCalculator Class

Write Tests for Extracted Classes

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