Implementation:SeleniumHQ Selenium Format Sh Script

Knowledge Sources	Selenium
Domains	Code_Quality, Continuous_Integration, Developer_Experience
Last Updated	2026-02-11 00:00 GMT

Overview

Concrete tool for automated multi-language code formatting provided by the scripts/format.sh script.

Description

format.sh is a Bash script (with set -eufo pipefail for strict error handling) that formats changed files using language-specific formatters. It supports four modes: default (all changes vs trunk including uncommitted work), --pre-commit (staged only via git diff --cached), --pre-push (committed vs trunk via git diff base..HEAD), and --all (everything, skipping change detection). The --lint flag adds linter checks (Python ruff check, Shell actionlint + shellcheck). Modes --pre-commit and --pre-push are mutually exclusive.

The script uses bazel info workspace to determine the workspace root and delegates formatting to Bazel-managed tools. It captures a baseline via git status --porcelain before formatting and compares afterward; if the porcelain output differs, it exits with code 1 and prints the names of modified files.

Usage

Run before committing or pushing. CI will fail if formatting changes are needed.

Code Reference

Source Location

• Repository: Selenium
• File: scripts/format.sh (L1-148)

Signature

./scripts/format.sh [OPTIONS]

Options:
  --all          Format all files (skip change detection)
  --pre-commit   Format only staged changes (git diff --cached)
  --pre-push     Format committed changes vs trunk (git diff base..HEAD)
  --lint         Run linters in addition to formatters
  (default)      All changes relative to trunk including uncommitted work

Key Implementation Details

#!/usr/bin/env bash
set -eufo pipefail

# Change detection uses git merge-base to find common ancestor with trunk
trunk_ref="$(git rev-parse --verify trunk 2>/dev/null || echo "")"
base="$(git merge-base HEAD "$trunk_ref" 2>/dev/null || echo "")"

# Default mode combines: committed + staged + unstaged + untracked
committed="$(git diff --name-only "$base" HEAD)"
staged="$(git diff --name-only --cached)"
unstaged="$(git diff --name-only)"
untracked="$(git ls-files --others --exclude-standard)"
changed="$(printf '%s\n%s\n%s\n%s' "$committed" "$staged" "$unstaged" "$untracked" | sort -u)"

# Helper checks if pattern matches changed files (or if --all)
changed_matches() {
    [[ "$format_all" == "true" ]] || echo "$changed" | grep -qE "$1"
}

# Always run buildifier and copyright
bazel run //:buildifier
bazel run //scripts:update_copyright

# Conditionally run per language:
# Java:       google-java-format --replace (find *.java in java/)
# JavaScript: prettier --write
# Ruby:       rubocop -a (--fail-level F without --lint)
# Rust:       @rules_rust//:rustfmt
# Python:     ruff check (if --lint) + ruff format
# .NET:       dotnet format style --severity warn + whitespace
# Shell/CI:   actionlint with shellcheck (if --lint)

# Compare baseline to detect formatter changes
baseline="$(git status --porcelain)"
# ... after formatting ...
if [[ "$(git status --porcelain)" != "$baseline" ]]; then
    exit 1
fi

Import

N/A - Shell script

I/O Contract

Inputs

Name	Type	Required	Description
--all	Flag	No	Format everything, skip change detection
--pre-commit	Flag	No	Format staged changes only (mutually exclusive with --pre-push)
--pre-push	Flag	No	Format committed changes vs trunk (mutually exclusive with --pre-commit)
--lint	Flag	No	Also run linters (ruff check, actionlint, shellcheck)

Outputs

Name	Type	Description
Formatted files	Modified files	Source files reformatted in-place
Exit code	int	0 = no changes needed (format check passed), 1 = files were modified by formatters

Formatter-to-Language Mapping

File Pattern	Formatter	Bazel Target
^java/	google-java-format	//scripts:google-java-format
^javascript/selenium-webdriver/	prettier	//javascript:prettier
^rb/, ^rake_tasks/, ^Rakefile	rubocop -a	//rb:rubocop
^rust/	rustfmt	@rules_rust//:rustfmt
^py/	ruff format (+ ruff check)	//py:ruff-format, //py:ruff-check
^dotnet/	dotnet format	//dotnet:format
(always)	buildifier	//:buildifier
(always)	update_copyright	//scripts:update_copyright
(--lint only)	actionlint + shellcheck	@multitool//tools/actionlint:cwd, @multitool//tools/shellcheck

Usage Examples

Before Committing

# Format all changes relative to trunk (default mode)
./scripts/format.sh

# Format only staged files (for pre-commit hook)
./scripts/format.sh --pre-commit

Full Format and Lint

# Format and lint everything
./scripts/format.sh --all --lint

Via ./go Wrapper

# Alternative: use the Rake wrapper
./go all:lint

CI Integration

# In CI, check if formatting is needed (exits 1 if changes detected)
./scripts/format.sh --pre-push
if [ $? -ne 0 ]; then
    echo "Formatting check failed. Run ./scripts/format.sh locally."
    exit 1
fi

Related Pages

Implements Principle

• Principle:SeleniumHQ_Selenium_Code_Formatting_Pipeline

Requires Environment

• Environment:SeleniumHQ_Selenium_Contributor_Development_Environment