Migrating To ESLint 9 And @iobroker/eslint-config A Guide For IoBroker Adapter Developers

Hey guys! 👋 If you're an ioBroker adapter developer, you've probably heard about ESLint 9. The ioBroker Check and Service Bot sent out a notification about it, and we're here to break down what it means for you. This article will guide you through the migration process, highlight the benefits of using @iobroker/eslint-config, and address any concerns you might have. Let's dive in!

What's the Deal with ESLint 9?

ESLint 9 is the latest major version of the popular JavaScript linting tool. If you're using Dependabot, you might have already seen pull requests suggesting an update. Don't worry, there's no immediate rush to upgrade. However, migrating to ESLint 9 and embracing the new standard ESLint configuration offered by the ioBroker core team at @iobroker/eslint-config is highly recommended. Using ESLint ensures code quality, consistency, and helps catch potential errors early on. It's like having a coding buddy that points out your typos and style inconsistencies – super helpful!

Why Migrate to ESLint 9?

Migrating to ESLint 9 brings several benefits to the table. First and foremost, you'll be using the latest and greatest features of ESLint, including performance improvements and new rule sets. ESLint helps you enforce consistent coding styles across your projects, which leads to more maintainable and readable code. This is especially crucial when working in a team or contributing to open-source projects. By keeping your tools up-to-date, you'll ensure your adapter code remains compatible with the latest JavaScript standards and best practices.

Furthermore, using the @iobroker/eslint-config package ensures that your adapter adheres to the standards set by the ioBroker core team. This uniformity simplifies collaboration, code reviews, and maintenance across the entire ioBroker ecosystem. Think of it as speaking the same language – everyone understands each other better! Plus, adopting a standardized configuration makes it easier to contribute to and learn from other adapters in the ioBroker community. The migration process might seem daunting at first, but the long-term benefits of improved code quality and consistency are well worth the effort. So, let's explore how you can make this transition smoothly.

Why Use @iobroker/eslint-config?

Migrating to ESLint 9, the ioBroker core team strongly recommends using their standard ESLint configuration, which is available as the @iobroker/eslint-config package. Why? Because it's awesome! 😉 This configuration is designed to provide a consistent linting experience across all ioBroker adapters. By using it, you ensure that your adapter's code style aligns with the core team's standards and best practices.

This consistency is a game-changer for several reasons. Firstly, it makes your code more readable and maintainable. When all adapters follow the same style guidelines, developers can easily jump between projects without having to adjust to different coding conventions. Secondly, it streamlines the code review process. Reviewers can focus on the logic and functionality of the code rather than getting bogged down in style nitpicks. Thirdly, it promotes collaboration within the ioBroker community. When everyone speaks the same coding language, it's much easier to contribute to and learn from each other's work. The @iobroker/eslint-config package includes a set of carefully curated rules that cover a wide range of JavaScript and TypeScript coding best practices. These rules help you catch potential bugs, avoid common pitfalls, and write code that is both efficient and elegant. By adopting this configuration, you're not just improving the quality of your own adapter, you're also contributing to the overall health and consistency of the ioBroker ecosystem. So, it's a win-win situation for everyone involved!

How to Migrate: The Migration Guide

To help you with the migration, the ioBroker team has published a detailed migration guide. You can find it here: https://github.com/ioBroker/ioBroker.eslint-config/blob/main/MIGRATION.md. This guide walks you through the process step-by-step, making the transition as smooth as possible. Don't worry, it's not as scary as it sounds!

The migration guide provides clear instructions on how to install the @iobroker/eslint-config package, configure your ESLint setup, and address any potential conflicts with your existing rules. It also covers common issues that you might encounter during the migration, such as Prettier reporting errors. The key steps generally involve installing the @iobroker/eslint-config package as a development dependency in your project. Then, you'll need to update your ESLint configuration file (.eslintrc.js or .eslintrc.yaml) to extend the @iobroker/eslint-config ruleset. This tells ESLint to use the ioBroker core team's configuration as the base for your linting rules. After that, you can run ESLint on your project to identify any issues that need to be addressed. The guide also explains how to use the --fix flag to automatically fix many of the common linting errors, which can save you a lot of time and effort. By following the migration guide closely, you can ensure a successful transition to ESLint 9 and @iobroker/eslint-config, bringing your adapter in line with the latest standards and best practices of the ioBroker community. So, grab a cup of coffee, open the guide, and let's get started!

Dealing with Prettier Issues

One thing to note is that Prettier might report several issues during the migration. Prettier is a code formatter that ensures your code adheres to a consistent style, such as indentation and line spacing. The good news is that most of these issues can be fixed automatically by running npm run lint -- --fix. This command tells ESLint to automatically apply fixes to your code based on the configured rules.

When you run this command, ESLint and Prettier work together to reformat your code according to the rules defined in your configuration. This can include things like adjusting indentation, adding or removing semicolons, and wrapping lines to a specific length. By using the --fix flag, you can quickly resolve many of the common style issues that might arise during the migration process. However, it's always a good idea to review the changes that are made to ensure they align with your expectations. Sometimes, the automatic fixes might not be perfect, and you might need to make manual adjustments to achieve the desired formatting. In addition to fixing style issues, running npm run lint -- --fix can also help identify and resolve potential code errors and inconsistencies. ESLint's rules are designed to catch common programming mistakes, such as unused variables, missing semicolons, and incorrect use of this. By addressing these issues early on, you can improve the overall quality and reliability of your code. So, if you encounter Prettier issues during the migration, don't panic! Just run npm run lint -- --fix, review the changes, and make any necessary adjustments. You'll be well on your way to a cleaner, more consistent codebase.

Flexibility and Customization

The ioBroker core team's rules are used (or will be used in the future) for all adapters maintained by them. This ensures that the configuration is well-reviewed and represents best practices. However, it's important to remember that you have the flexibility to adapt the rules for your adapter if you feel a strong need to do so. You can also exclude some files (maybe very old ones) from checking if necessary.

While the @iobroker/eslint-config provides a solid foundation for code quality and consistency, it's not a one-size-fits-all solution. Every adapter has its unique requirements and coding style, and there might be situations where the default rules don't quite fit your needs. That's why the ioBroker team has made it clear that you have the freedom to customize the ruleset to some extent. For example, if you have a particular coding pattern that is common in your adapter but flagged by ESLint, you can disable the relevant rule or adjust its severity. Similarly, if you have certain files that are legacy code or generated automatically, you might want to exclude them from linting to avoid unnecessary noise. When customizing the rules, it's essential to strike a balance between adhering to the overall ioBroker standards and accommodating the specific requirements of your adapter. Overriding too many rules can defeat the purpose of using @iobroker/eslint-config in the first place, while being too strict can hinder your development workflow. The key is to make informed decisions based on your understanding of the code and the potential impact of each rule. Remember, the goal is to improve code quality and maintainability, not to blindly follow a set of rules. So, don't be afraid to experiment and find the configuration that works best for you.

Recommendation, Not Mandate

To be clear, using @iobroker/eslint-config is strongly recommended but not mandatory. The ioBroker team believes it's the best way to ensure code quality and consistency across the ecosystem, but they also understand that every adapter developer has their own preferences and workflows.

This approach reflects the ioBroker community's emphasis on collaboration and shared standards while respecting individual autonomy. The core team recognizes that adapter developers are passionate about their projects and have valid reasons for making specific choices about their coding practices. By making @iobroker/eslint-config a recommendation rather than a requirement, the team encourages developers to adopt it because they see the value, not because they are forced to. This fosters a more positive and collaborative environment where developers are motivated to improve their code quality and contribute to the overall health of the ioBroker ecosystem. However, the strong recommendation also signals the importance of consistency and shared standards within the community. Adapters that adhere to the @iobroker/eslint-config guidelines are likely to be easier to maintain, review, and integrate with other components of the ioBroker system. This can lead to a more seamless user experience and reduce the likelihood of compatibility issues. So, while you have the freedom to choose, it's worth carefully considering the benefits of using @iobroker/eslint-config and how it can contribute to the long-term success of your adapter and the ioBroker community as a whole.

Thanks for Maintaining Adapters!

The ioBroker Check and Service Bot, and the entire ioBroker community, extend a huge THANK YOU to all adapter developers for their hard work and dedication. Maintaining adapters is a labor of love, and your efforts are greatly appreciated. Let's continue working together to create the best user experience possible!

Questions? Contact the Bot!

If you have any questions about migrating to ESLint 9 or using @iobroker/eslint-config, don't hesitate to contact the ioBroker Bot (@iobroker-bot). The bot is there to help you and provide guidance.

Conclusion

Migrating to ESLint 9 and embracing @iobroker/eslint-config is a fantastic step towards improving code quality and consistency in your ioBroker adapters. While it might seem like a big task, the benefits are well worth the effort. By following the migration guide, addressing Prettier issues, and leveraging the flexibility of the configuration, you can ensure a smooth transition. Remember, the ioBroker community is here to support you, so don't hesitate to reach out with any questions. Happy coding, guys! 🎉