How Can Better Coding Practices Be Promoted When Adding New Features To An Existing Application With Poor Source Code?

Updating an application with poor source code can feel like trying to build a robust system on unstable foundations. How do you add new features without making the system hard to maintain? The answer lies in adopting better coding practices during the process.

Better coding practices while adding new features is crucial for long-term success and enhancing the app’s functionality. Whether it is cleaning up messy code, implementing testing, or introducing clear documentation, these practices can make a big difference.

In this article, we’ll explore simple strategies that not only fix challenges of adding features in legacy apps (apps built with poor source code) but also set the stage for smoother updates in the future.

Analyze the Current State of the Codebase

It is essential to perform a comprehensive analysis of the existing codebase. This includes identifying:

• Complex or Redundant Code: Sections that are unnecessarily complex or repetitive.
• Violated Principles: Areas where coding standards including SOLID or DRY are not followed.
• High-risk Areas: Sections vulnerable to bugs or that need frequent changes.

Make a Coding Standard

Using a coding standard helps improve software quality and stability. It provides clear rules for developers to write consistent code. When everyone follows the same rules, the code works better, is easier to maintain, and has fewer bugs. These standards should include:

• Code Formatting: Set rules for naming, indentation, and comments to keep the code consistent.
• Ideal Approaches: Follow design concepts like keeping code modular, reusable, and focused on one task.
• Tools & Guides: Use tools like linters and style guides (PEP 8 for Python, ESLint for JavaScript) to automatically check the code.

Refactor Incrementally

Refactoring the whole codebase at once can be risky and hard to manage. The gradual approach to refactor in small and manageable steps allows for continuous improvement while minimizing major issues. Start by working on areas related to new features or recent changes, then focus on key parts like core modules or frequently used functions. Prioritize refactoring parts that impact performance or are hard to maintain. Use automated tests to verify the refactored code doesn’t break anything or introduce new bugs.

Write Testable Code

Poor code often lacks test coverage and makes it hard to ensure everything works. To fix this, writing testable code is crucial for reliable software, especially when adding new features. Write tests for new and updated code to make sure it works correctly. Follow test-driven development (TDD) by writing tests before the code to create cleaner designs. Automated testing tools like Jest, Mocha, or NUnit make testing faster and more efficient. Better test coverage helps build confidence in your software’s reliability.

Structure New Features into Modules

When adding new features to a project, it’s important to make sure the new code is clean and organized into modules. The approach to modularize code allows adding new features independently, making it easier to manage. Start by separating parts of the code to minimize dependencies. Design patterns like Model-View-Controller (MVC) help maintain a clear, scalable structure. For larger features, use microservices to build them as separate components, reducing the risk of affecting the existing code.

Set Up Automatic Code Quality Checks

Automatic code quality checks make it easier to maintain high standards by reducing the effort and errors that come with manual checks. Tools like SonarQube and CodeClimate can find issues in the code automatically and make sure the code follows the standard practices. Adding these checks to Continuous Integration (CI) pipelines helps developers spot problems early. This helps in saving time and effort down the line. Keeping libraries and frameworks updated improves compatibility and security, making the software development process smoother and more efficient.

Use Code Reviews

Regular code reviews improve code quality and promote accountability and ongoing progress within the team. It helps detect problems early, share helpful ideas, encourage learning, and ensure good practices and high-quality code. Using a checklist for readability, maintainability, and coding standards makes the process smoother and more consistent. Tools like GitHub, GitLab, or Bitbucket help make reviews easier to maintain over time by providing integrated systems that streamline collaboration and feedback.

Wrapping Up

Adding features to an application with poor source code while promoting better coding practices is not an easy task. By taking a step-by-step approach that focuses on small enhancements, testing, and teamwork, teams can slowly turn a difficult codebase into a system that’s easier to maintain and scale. The key lies in balancing short-term feature delivery with long-term quality, ensuring sustainable growth for the application and its users.