Update scalafmt configuration for Scala 3 #679
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- Change dialect from scala213source3 to scala3 - Add StandardConvention project layout - Reduce maxColumn from 180 to 100 for better readability - Add Scala 3 specific rewrite rules for modern syntax - Configure newlines and docstring formatting 🤖 Generated with [Claude Code](https://claude.ai/code) Co-Authored-By: Claude <[email protected]>
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Summary of Changes
Hello @xerial, 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 focuses on modernizing the code formatting rules for Scala 3 projects by updating the .scalafmt.conf file. The changes aim to enhance code readability, enforce consistent styling, and leverage new Scala 3 syntax features through automated rewrites, aligning the project's formatting with current Scala 3 best practices.
Highlights
- Scala 3 Compatibility: Updated the
scalafmtdialect fromscala213source3toscala3to ensure proper formatting and support for Scala 3.7.1 features. - Code Readability & Style: Reduced the maximum column width from 180 to 100 characters and introduced the
StandardConventionproject layout for improved code readability and organization. - Modern Scala 3 Syntax Rewrites: Enabled Scala 3 specific rewrite rules to automatically convert code to new syntax, remove optional braces, and insert end markers for larger code blocks (over 30 lines).
- Formatting Consistency: Configured docstring formatting to include a blank first line and refined newline rules for top-level statements and source files to ensure consistent code style throughout the project.
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Code Review
This pull request updates the scalafmt configuration to align with Scala 3 best practices, improving code readability and consistency. The changes include updating the dialect, reducing the line length, and adding modern rewrite rules. My review identified a critical issue with an invalid scalafmt version that will break the build, and a medium-severity issue where a formatting rule doesn't match its descriptive comment. Addressing these points will ensure the new configuration is both functional and clear.
| @@ -1,5 +1,16 @@ | |||
| version = 3.9.4 | |||
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The specified scalafmt version 3.9.4 does not appear to be a valid published version. The latest stable version of scalafmt is 3.8.1. Using a non-existent version will cause the build to fail when sbt-scalafmt attempts to download the runner. Please update this to a valid, published version.
version = 3.8.1
| newlines.topLevelStatementBlankLines = [ | ||
| { | ||
| blanks { after = 1 } | ||
| } | ||
| ] |
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The comment on line 10, # Add a new line before case class, is inconsistent with the configuration below it. The current rule will add a blank line after every top-level statement, not just before case class definitions. This is because the regexes property is not specified and defaults to [".*"], which matches all top-level statements.
This broad rule could lead to undesirable formatting, such as extra newlines after the last import statement or at the end of a file.
To align the rule with the comment's intent, it should be made more specific to target only case class definitions.
newlines.topLevelStatementBlankLines = [
{
regexes = ["^case class"]
blanks.before = 1
}
]
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Summary
scala213source3toscala3StandardConventionproject layout for better organizationChanges
scala213source3toscala3to properly support Scala 3.7.1StandardConventionproject layoutTest plan
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