Support the new configuration format

Oct 13, 2025 by wbrum.org 51 views

Introduction

As part of the ongoing efforts to modernize and improve the functionality of ESLint, we are proposing a change to the migrate-config package to utilize the defineConfig() method. This change aims to align the migration tool with the latest developments in ESLint, specifically the release of defineConfig(). In this article, we will delve into the reasons behind this proposal, the benefits of the change, and the steps required to implement it.

Problem Statement

The recent release of defineConfig() has brought about significant improvements to the configuration management system in ESLint. However, the migrate-config package, which is responsible for migrating configurations from the old format to the new one, still relies on the outdated format. This discrepancy creates a barrier for users who want to take advantage of the new features and benefits offered by defineConfig().

The Need for Change

The current state of migrate-config hinders the adoption of defineConfig() by:

Incompatibility: The migration tool is not compatible with the new configuration format, making it difficult for users to migrate their configurations.
Limited functionality: The outdated format restricts the functionality of migrate-config, preventing it from fully leveraging the capabilities of defineConfig().

Proposed Solution

To address these issues, we propose updating migrate-config to use defineConfig(). This change will enable the migration tool to:

Support the new configuration format: By utilizing defineConfig(), migrate-config will be able to handle configurations in the latest format, ensuring seamless migration for users.
Leverage the full potential of defineConfig(): With the updated migration tool, users will be able to take full advantage of the features and benefits offered by defineConfig().

Implementation Plan

To implement this change, we will follow these steps:

Update the migration logic: Modify the migration logic in migrate-config to use defineConfig() instead of the outdated format.
Test the updated migration tool: Thoroughly test the updated migrate-config package to ensure it works as expected and does not introduce any regressions.
Publish the updated package: Once the updated package has been thoroughly tested, publish it to the npm registry, making it available for users to install and use.

Participation and Next Steps

We invite the ESLint community to participate in this change by:

Reviewing the proposed changes: Carefully review the proposed changes and provide feedback on the implementation plan.
Testing the updated migration tool: Test the updated migrate-config package and report any issues or regressions found.
Contributing to the implementation: Contribute to the implementation of the change by submitting pull requests or providing code reviews.

Conclusion

Updating migrate-config to use defineConfig() is a crucial step in modernizing the ESLint configuration management system. By aligning the migration tool with the latest developments in ESLint, we can ensure a smoother transition for users and provide them with the benefits of the new configuration format. We encourage the ESLint community to participate in this change and contribute to the implementation of the updated migrate-config package.

Additional Information

Which packages would you like to change?

@eslint/compat
@eslint/config-array
@eslint/config-helpers
@eslint/core
@eslint/migrate-config (selected)
@eslint/object-schema
@eslint/plugin-kit

What problem do you want to solve?

The recent release of defineConfig() has brought about significant improvements to the configuration management system in ESLint. However, the migrate-config package still relies on the outdated format, creating a barrier for users who want to take advantage of the new features and benefits offered by defineConfig().

What do you think is the correct solution?

Updating migrate-config to use defineConfig() is the correct solution. This change will enable the migration tool to support the new configuration format and leverage the full potential of defineConfig().

Participation

I am willing to submit a pull request for this change. (selected)

Additional comments

Introduction

As we discussed in our previous article, updating migrate-config to use defineConfig() is a crucial step in modernizing the ESLint configuration management system. In this Q&A article, we will address some of the frequently asked questions about this change and provide more information on the implementation plan.

Q: What is the main benefit of updating migrate-config to use defineConfig()?

A: The main benefit of updating migrate-config to use defineConfig() is that it will enable the migration tool to support the new configuration format and leverage the full potential of defineConfig(). This will allow users to take full advantage of the features and benefits offered by defineConfig().

Q: Why is the current migrate-config package not compatible with defineConfig()?

A: The current migrate-config package is not compatible with defineConfig() because it relies on the outdated format. This format is no longer supported by defineConfig(), which is why the migration tool is not able to handle configurations in the latest format.

Q: How will the updated migrate-config package handle configurations in the new format?

A: The updated migrate-config package will use defineConfig() to handle configurations in the new format. This will ensure that the migration tool is able to support the latest configuration format and provide users with a seamless migration experience.

Q: What are the steps involved in implementing this change?

A: The steps involved in implementing this change are:

Update the migration logic: Modify the migration logic in migrate-config to use defineConfig() instead of the outdated format.
Test the updated migration tool: Thoroughly test the updated migrate-config package to ensure it works as expected and does not introduce any regressions.
Publish the updated package: Once the updated package has been thoroughly tested, publish it to the npm registry, making it available for users to install and use.

Q: How can the ESLint community participate in this change?

A: The ESLint community can participate in this change by:

Reviewing the proposed changes: Carefully review the proposed changes and provide feedback on the implementation plan.
Testing the updated migration tool: Test the updated migrate-config package and report any issues or regressions found.
Contributing to the implementation: Contribute to the implementation of the change by submitting pull requests or providing code reviews.

Q: What is the expected timeline for implementing this change?

A: The expected timeline for implementing this change is as follows:

Short-term: Update the migration logic and test the updated migration tool.
Medium-term: Publish the updated package and make it available for users to install and use.
Long-term: Monitor the performance of the updated migrate-config package and make any necessary adjustments.

Q: What are the potential risks associated with this change?

A: The potential risks associated with this change are:

Regressions: Introducing regressions in the migration tool that could affect the functionality of migrate-config.
Incompatibility: Incompatibility issues between the updated migrate-config package and other ESLint packages.
Performance issues: Performance issues with the updated migrate-config package that could affect the user experience.

Conclusion

Updating migrate-config to use defineConfig() is a crucial step in modernizing the ESLint configuration management system. By addressing some of the frequently asked questions about this change, we hope to provide more information on the implementation plan and encourage the ESLint community to participate in this change.