pre-commit.sh

#!/bin/sh

# Runs SwiftFormat on changed Swift files in the project.
# The re-formatting may not be caught at commit time, though, and so may require a subsequent commit/amending.

# If any command fails, exit immediately with that command's exit status.
# shellcheck disable=SC3040
set -eo pipefail

# Redirect output to stderr.
exec 1>&2

# Add Homebrew (Rosetta/Intel and Apple Silicon paths) and Mint to the PATH for git GUIs to find SwiftFormat.
export PATH="/usr/local/bin/:/opt/homebrew/bin:~/.mint/bin/:$PATH"

# Find all changed files for this commit.
CHANGED_FILES=$(git diff --name-only --cached --diff-filter=ACMR)
# Get only changed files that match the given file suffix pattern.
get_pattern_files() {
    pattern=$(echo "$*" | sed "s/ /\$\\\|/g")
    echo "$CHANGED_FILES" | { grep "$pattern$" || true; }
}

# Get all changed Swift files.
CHANGED_SWIFT_FILES=$(get_pattern_files .swift)

# Base for relative pathing.
hooks_dir=$(dirname "$0")

# shellcheck disable=SC3010
if [[ -n "$CHANGED_SWIFT_FILES" ]]
then
	cd "$hooks_dir/../../"
	swiftformat . --quiet
fi