Refactoring Expensify App How To Remove Onyx.connect For Country Code

Introduction

In the ongoing effort to modernize and streamline the Expensify application, a crucial step involves deprecating the usage of Onyx.connect(). This article delves into the process of removing Onyx.connect() for the key ONYXKEYS.COUNTRY_CODE within the src/libs/LocalePhoneNumber.ts module. This task is part of a larger initiative, as outlined in the Parent Issue, to enhance the app's performance, maintainability, and overall architecture. By addressing this specific instance, we contribute to the broader goal of reducing dependencies on older patterns and embracing more efficient data management strategies. The following sections will explore the context, methodology, and implications of this refactoring effort.

Understanding the Importance of Deprecating Onyx.connect()

Deprecating Onyx.connect() is a strategic move to modernize the Expensify application's architecture. Onyx.connect(), while serving its purpose in the past, introduces certain complexities and potential performance bottlenecks. By moving away from this pattern, the application can benefit from improved data flow, reduced memory consumption, and a more predictable state management system. This refactoring effort aligns with the best practices in modern application development and sets the stage for future enhancements and scalability. The transition also allows for the adoption of more contemporary data fetching and management techniques, ultimately leading to a more robust and efficient application. Furthermore, reducing the reliance on Onyx.connect() simplifies the codebase, making it easier to maintain and extend. This simplification is crucial for a large and evolving application like Expensify, where multiple developers contribute to the codebase regularly. In essence, deprecating Onyx.connect() is an investment in the long-term health and performance of the Expensify application.

The Role of src/libs/LocalePhoneNumber.ts

The src/libs/LocalePhoneNumber.ts module plays a vital role in handling phone number formatting and validation within the Expensify application. This module is responsible for ensuring that phone numbers are correctly formatted based on the user's country code. Given the global user base of Expensify, accurate and reliable phone number handling is essential for various functionalities, including user authentication, communication, and data consistency. By refactoring this module, we not only improve its performance but also ensure that it remains robust and adaptable to future requirements. The LocalePhoneNumber.ts module directly impacts the user experience, as incorrect phone number formatting can lead to issues with SMS verification, contact synchronization, and other critical features. Therefore, any changes to this module must be carefully implemented and thoroughly tested to avoid introducing regressions. The refactoring process also provides an opportunity to review and optimize the existing code, ensuring that it adheres to the latest coding standards and best practices. In the context of deprecating Onyx.connect(), this module serves as a key target due to its interaction with global settings and user preferences, making it a prime candidate for improved data management strategies.

The Significance of ONYXKEYS.COUNTRY_CODE

ONYXKEYS.COUNTRY_CODE is a crucial piece of state within the Expensify application, dictating how phone numbers are formatted and validated. The COUNTRY_CODE influences various aspects of the application, from displaying phone number input fields to validating user-provided numbers. As such, managing this piece of state efficiently is paramount. By removing Onyx.connect() for this key, we aim to streamline how the country code is accessed and utilized throughout the application. This not only improves performance but also reduces the potential for race conditions and inconsistencies. The refactoring process will involve identifying all components and modules that currently rely on Onyx.connect() to access the country code and updating them to use alternative data fetching methods. This ensures a smooth transition and minimizes the risk of introducing bugs or regressions. The choice of ONYXKEYS.COUNTRY_CODE as a target for this refactoring effort highlights the importance of global settings in the Expensify application and the need to manage them efficiently.

Detailed Steps for Removing Onyx.connect()

The process of removing Onyx.connect() involves a structured approach to ensure minimal disruption and maximum reliability. This includes creating unit tests, refactoring methods, ensuring test suite integrity, and reinforcing testing with functional and QA tests. By following this methodology, we can confidently deprecate Onyx.connect() while maintaining the application's stability and functionality. Each step is designed to address potential issues proactively and ensure that the refactored code is robust and efficient.

Step 1: Creating Unit Tests Before Refactoring

Before making any changes to the code, it is essential to create comprehensive unit tests. These tests serve as a safety net, ensuring that the refactored code behaves as expected. Unit tests focus on individual functions and methods, isolating them from the rest of the application to verify their correctness. In the context of src/libs/LocalePhoneNumber.ts, this means writing tests for methods that utilize the COUNTRY_CODE obtained via Onyx.connect(). These tests should cover a range of scenarios, including different country codes and edge cases. The unit tests should be designed to fail before the refactoring, confirming that they are indeed testing the relevant functionality. Once the refactoring is complete, these tests should pass, providing confidence that the changes have not introduced any regressions. The process of writing unit tests also helps in understanding the existing code and identifying potential areas for improvement. By taking a test-driven development (TDD) approach, we ensure that the refactoring is guided by clear and measurable objectives.

Step 2: Refactoring the Methods

The core of this task involves refactoring the methods that currently use Onyx.connect() to access ONYXKEYS.COUNTRY_CODE. This requires identifying the specific lines of code where Onyx.connect() is used and replacing them with alternative data fetching mechanisms. The goal is to achieve the same functionality without relying on Onyx.connect(). This may involve using other state management solutions, dependency injection, or direct data fetching from the appropriate sources. The refactoring process should be incremental, with each change being small and focused. This minimizes the risk of introducing errors and makes it easier to debug any issues that may arise. The refactored code should be clean, readable, and well-documented, adhering to the project's coding standards. It is also important to consider the performance implications of the changes and ensure that the new approach is as efficient as or more efficient than the old one. The refactoring should also address any potential memory leaks or resource contention issues associated with the previous implementation. By carefully refactoring the methods, we can ensure a smooth transition away from Onyx.connect() without compromising the application's functionality or performance.

Step 3: Ensuring Unit Tests Still Run After Refactoring

After refactoring the methods, it is crucial to run the unit tests to ensure that they still pass. This step validates that the changes have not introduced any regressions and that the refactored code behaves as expected. If any tests fail, it indicates that there is an issue with the refactoring that needs to be addressed. The failing tests provide valuable information about the nature of the problem and help in identifying the root cause. Debugging and fixing the failing tests is an iterative process, involving analyzing the code, understanding the test failures, and making the necessary adjustments. Once all the unit tests pass, it provides a high degree of confidence that the refactoring has been successful. However, unit tests are not the only form of testing required. It is also important to reinforce the testing with functional and QA tests to ensure that the changes work correctly in the context of the broader application.

Step 4: Reinforcing Testing with Functional and QA Tests

To ensure the robustness of the refactored code, it is essential to supplement unit tests with functional and QA tests. Functional tests verify that the methods work correctly in real-world scenarios, simulating user interactions and workflows. QA tests, on the other hand, involve manual testing by quality assurance professionals to identify any edge cases or usability issues that may not be caught by automated tests. Functional tests can be automated to provide continuous integration and regression testing, ensuring that the changes do not break existing functionality. QA tests provide a human perspective, identifying issues that may be missed by automated tests, such as UI glitches or unexpected behavior. The combination of unit, functional, and QA tests provides a comprehensive testing strategy, ensuring that the refactored code is reliable and meets the needs of the users. In the context of src/libs/LocalePhoneNumber.ts, functional tests may involve simulating user input of phone numbers from different countries and verifying that they are correctly formatted and validated. QA tests may involve manually testing the phone number input fields in various scenarios, such as registration, profile updates, and contact synchronization. By reinforcing testing with functional and QA tests, we can confidently deprecate Onyx.connect() and ensure a smooth transition for the Expensify application.

Step 5: Decreasing Allowable ESLint Warnings

As a final step, after successfully removing Onyx.connect(), the number of allowable ESLint warnings should be decreased. This ensures that the codebase remains clean and adheres to the project's coding standards. ESLint is a tool that identifies potential issues in the code, such as unused variables, syntax errors, and style violations. By reducing the number of allowable warnings, we encourage developers to address these issues and maintain a high-quality codebase. The specific file mentioned, package.json, contains the configuration for ESLint, including the number of allowable warnings. By updating this configuration, we enforce the new standard and ensure that the codebase remains consistent. This step is crucial for maintaining the long-term health of the application and preventing technical debt from accumulating. It also promotes a culture of code quality and encourages developers to write clean, maintainable code. By decreasing the allowable ESLint warnings, we ensure that the codebase reflects the improvements made by deprecating Onyx.connect() and remains robust and efficient.

Impact and Benefits of Removing Onyx.connect()

Removing Onyx.connect() has several positive impacts on the Expensify application. The benefits include improved performance, reduced complexity, and enhanced maintainability. By streamlining data access and reducing dependencies on older patterns, the application becomes more efficient and easier to evolve. This refactoring effort not only addresses immediate concerns but also lays the groundwork for future enhancements and scalability.

Improved Performance

One of the primary benefits of removing Onyx.connect() is improved performance. By eliminating the overhead associated with this pattern, the application can access data more efficiently. This leads to faster load times, smoother user interactions, and a more responsive overall experience. The performance improvements are particularly noticeable in areas of the application that heavily rely on data fetching and state management. By optimizing these critical components, we can significantly enhance the user experience and ensure that the application remains performant even under heavy load. The removal of Onyx.connect() also reduces the potential for memory leaks and resource contention issues, further contributing to improved performance. In the context of src/libs/LocalePhoneNumber.ts, this means that phone number formatting and validation can be performed more quickly and efficiently, improving the responsiveness of features that rely on this module. By prioritizing performance, we ensure that the Expensify application remains competitive and meets the expectations of its users.

Reduced Complexity

Removing Onyx.connect() also reduces the complexity of the codebase. By simplifying the data access patterns, we make the application easier to understand, maintain, and extend. This is particularly important for a large and evolving application like Expensify, where multiple developers contribute to the codebase. A less complex codebase reduces the risk of introducing bugs and makes it easier to onboard new developers. It also facilitates code reviews and collaboration, as developers can more easily understand the code and identify potential issues. The removal of Onyx.connect() also allows for the adoption of more modern and standardized data management techniques, further simplifying the codebase. In the context of src/libs/LocalePhoneNumber.ts, this means that the logic for handling phone number formatting and validation becomes more straightforward and easier to reason about. By reducing complexity, we improve the overall maintainability and scalability of the Expensify application.

Enhanced Maintainability

The reduction in complexity directly translates to enhanced maintainability. A simpler codebase is easier to maintain, debug, and update. This reduces the time and effort required to address issues and implement new features. Enhanced maintainability also improves the long-term health of the application, as it becomes easier to adapt to changing requirements and technologies. The removal of Onyx.connect() contributes to this enhanced maintainability by reducing the dependencies on older patterns and promoting the adoption of more modern data management techniques. This makes the codebase more resilient to future changes and reduces the risk of technical debt accumulating. In the context of src/libs/LocalePhoneNumber.ts, this means that the logic for handling phone number formatting and validation can be more easily updated and adapted to new requirements, such as changes in international dialing codes or phone number formats. By enhancing maintainability, we ensure that the Expensify application remains robust and adaptable to the evolving needs of its users.

Conclusion

Removing Onyx.connect() for ONYXKEYS.COUNTRY_CODE in src/libs/LocalePhoneNumber.ts is a significant step towards modernizing the Expensify application. This refactoring effort aligns with the broader goal of deprecating Onyx.connect() and improving the app's performance, maintainability, and overall architecture. By following a structured approach that includes unit testing, refactoring, and functional and QA testing, we can confidently deprecate Onyx.connect() while ensuring the application's stability and functionality. The benefits of this refactoring include improved performance, reduced complexity, and enhanced maintainability, all of which contribute to a better user experience and a more robust application. As we continue to deprecate Onyx.connect() in other parts of the application, we will further realize these benefits and ensure that Expensify remains a leading solution for expense management. The dedication to code quality and continuous improvement will not only benefit the application's performance but also streamline the development process, allowing the team to innovate and adapt more efficiently to the evolving needs of its users. The successful removal of Onyx.connect() in this context serves as a blueprint for future refactoring efforts, reinforcing the commitment to technical excellence and user satisfaction.