feat(errors): introduce a new error handling system with support for multiple errors

[m-mizutani]

No description provided.

[gemini-code-assist]

Summary of Changes

Hello @m-mizutani, I'm Gemini Code Assist¹! I'm currently reviewing this pull request and will post my feedback shortly. In the meantime, here's a summary to help you and other reviewers quickly get up to speed!

This pull request significantly overhauls the error handling system. It introduces a dedicated Error type for detailed single error reporting, complete with contextual data and stack traces. Concurrently, it establishes an Errors type to robustly manage and aggregate multiple errors, aligning with modern Go practices for comprehensive error diagnostics.

Highlights

• Introduction of a new goerr.Error type: A comprehensive Error type has been introduced in error.go to provide rich context for individual errors, including custom values, tags, unique IDs, and detailed stack traces. It also supports fmt.Formatter, log/slog.LogValuer, and json.Marshaler interfaces for enhanced debugging and logging.
• Introduction of a new goerr.Errors type for multiple error handling: A dedicated Errors type has been added in errors.go to aggregate and manage multiple errors. This type provides methods like Join, Append, Unwrap (for []error), Is, and As to facilitate robust handling of composite errors, aligning with modern Go error patterns.
• Refactoring and separation of concerns: The error handling logic has been refactored. The core goerr.Error type and its functionalities are now defined in error.go, while errors.go is solely dedicated to the goerr.Errors type for handling collections of errors, improving modularity and clarity.

Using Gemini Code Assist

The full guide for Gemini Code Assist can be found on our documentation page, here are some quick tips.

Invoking Gemini

You can request assistance from Gemini at any point in your pull request via creating an issue comment (i.e. comment on the pull request page) using either /gemini <command> or @gemini-code-assist <command>. Below is a summary of the supported commands.

Feature	Command	Description
Code Review	/gemini review	Performs a code review for the current pull request in its current state.
Pull Request Summary	/gemini summary	Provides a summary of the current pull request in its current state.
Comment	@gemini-code-assist	Responds in comments when explicitly tagged, both in issue comments and review comments.
Help	/gemini help	Displays a list of available commands.

Customization

To customize Gemini Code Assist for GitHub experience, repository maintainers can create a configuration file and/or provide a custom code review style guide (such as PEP-8 for Python) by creating and adding files to a .gemini/ folder in the base of the repository. Detailed instructions can be found here.

Limitations & Feedback

Gemini Code Assist may make mistakes. Please leave feedback on any instances where its feedback is incorrect or counter productive. You can react with 👍 and 👎 on @gemini-code-assist comments. If you're interested in giving your feedback about your experience with Gemini Code Assist for Github and other Google products, sign up here.

You can also get AI-powered code generation, chat, as well as code reviews directly in the IDE at no cost with the Gemini Code Assist IDE Extension.

Footnotes

1. Review the Privacy Notices, Generative AI Prohibited Use Policy, Terms of Service, and learn how to configure Gemini Code Assist in GitHub here. Gemini can make mistakes, so double check it and use code with caution. ↩

[gemini-code-assist]

Code Review

This pull request introduces a new error handling system with goerr.Error for single errors with context and goerr.Errors for multiple errors. The implementation is comprehensive, covering wrapping, context propagation, logging, and JSON marshaling. My review focuses on improving consistency, fixing bugs in logging and serialization, and enhancing performance. I've also suggested improvements to the tests to make them more robust and catch these kinds of issues in the future.