brave-core/docs/ignoring_format_checks.md

Ignoring Files from Format and Presubmit Checks

This document describes all the ways to ignore files from format and presubmit checks in the Brave codebase. The main use cases are ignoring files that are vendored from external sources or generated by tools.

Quick Reference Table

File Type / Check	Configuration File
C/C++	add .clang-format in target directory
Java	does not support configuration
JS/TS/CSS/etc.	//brave/.prettierignore
Python	//brave/.yapfignore
Rust	//.rustfmt.toml (via patching)
Swift	add // swift-format-ignore-file comment
Presubmit Checks	//brave/chromium_presubmit_config.json5

Detailed Instructions

C/C++ Files (clang-format)

To ignore C/C++ files from clang-format checks, you need to add a .clang-format file in the target directory with the following configuration:

DisableFormat: true
SortIncludes: false

This will disable both formatting and include sorting for files in that directory and its subdirectories.

Java Files

Chromium uses google-java-format for Java code formatting. Unlike other formatters, google-java-format does not support ignore files or directory-level configuration.

JavaScript/TypeScript/CSS/HTML Files

To ignore JavaScript, TypeScript, CSS, HTML, and other files handled by Prettier, add them to //brave/.prettierignore.

The .prettierignore file uses gitignore-style patterns to exclude files from Prettier formatting.

Python Files

To ignore Python files from formatting checks, add them to //brave/.yapfignore.

The .yapfignore file uses pattern matching (fnmatch) to exclude files from yapf formatting. Add one pattern per line.

Rust Files

To ignore directories from rustfmt formatting checks, you need to modify //.rustfmt.toml via patching.

The .rustfmt.toml file contains an ignore array that lists directories to exclude from rustfmt formatting. Add directory patterns to this array to ignore them.

Swift Files

To ignore Swift files from swift-format checks, add a comment at the top of the file:

// swift-format-ignore-file

To ignore specific lines within a Swift file, add a comment before the line:

// swift-format-ignore
let example = ...

The swift-format configuration is located at //brave/ios/.swift-format and controls formatting rules, but file-level ignores must be done using inline comments.

See for more details: https://github.com/swiftlang/swift-format/blob/main/Documentation/IgnoringSource.md

Presubmit Checks

To ignore files from presubmit checks, you need to adjust the default_files_to_skip configuration in //brave/chromium_presubmit_config.json5.

This configuration controls which files are skipped during presubmit checks. This does not affect the formatting checks.