Run SwiftLint against files which have been changed in the current branch relative to RELATIVE_BRANCH (eg. master)

swift-lint-modified-files.sh

#!/bin/bash

# Path to the repository root folder
REPO_ROOT_DIR=$1
# The branch name relative to which the modified files will be determined
RELATIVE_BRANCH=$2
# The path to the SwiftLint command.
SWIFT_LINT_PATH=$3

run_swiftlint() {
    local filename="${1}"
    if [[ "${filename##*.}" == "swift" ]]; then
        $SWIFT_LINT_PATH lint --path "${filename}" --lenient
    fi
}

run_swiftlint_modified_files() {
	# Run SwiftLint against files which have been changed in the current branch relative to RELATIVE_BRANCH
	git diff $RELATIVE_BRANCH --name-only | while read filename; do run_swiftlint "${filename}"; done
}

pushd $REPO_ROOT_DIR
run_swiftlint_modified_files
popd