Pre-commit git hook to run `lintr` on R files as they are committed, and block commit if `lintr` finds problems. Inspired by: https://gist.github.com/geuis/1489bbd1a8e47e86db38

pre-commit

#!/bin/sh
staged=$(git diff --staged --name-only | grep ".R$")
if [ "$staged" = '' ]; then
	printf "\e[0;32mDidn't find any staged R files to lint.\n\e[0m"
	exit 0
fi

printf "\e[0;32mLinting staged R files...\n\e[0m"

linter="
#! /usr/bin/R
if (!(\"lintr\" %in% installed.packages()[,\"Package\"])) {
	print(\"lintr not found. make sure lintr is installed.\")
	quit(\"no\", 1, runLast = FALSE)
}
library(lintr)
args <- commandArgs(trailingOnly = TRUE)
print(lint(args[2]))
"

echo "$linter" > .linter.R

pass=true
# run each staged file through the linter
for file in ${staged}; do
	# echo the staged file, not the file on disk, to a cache file.
	# prevents the following:
	# 1. stages file with linter failures
	# 2. gets linter failure, goes to fix file
	# 3. doesn't re-stage fixes, tries to commit the bad original
	echo "$(git show :${file})" > .lint-file

	# run the linting script against the cache file
	result=$(Rscript .linter.R --args .lint-file)

	# Check if linter found anything
	if [ "$result" != "" ]; then

		# write result to .lint-file
		echo "$result" > .lint-file
		# fix line references from .lint-file to source file
		sed -i '' -e "s/\.lint-file/$file/g" .lint-file
  	printf "\e[0;31mlintr found: ${file}\n\e[0m"
  	cat .lint-file
  	pass=false
	else
  	printf "\e[0;32mlintr passed: ${file}\n\e[0m"
	fi
done

# remove the linter cache file
rm .lint-file .linter.R

if ! $pass; then
	printf "\e[0;31mLinting failed for this commit. "
	printf "Make the corrections above, then re-stage.\n\e[0m"
	exit 1
else
	echo ""
	printf "\e[0;32mLinting passed for this commit.\n\e[0m"
	exit 0
fi