pre-commit

#!/usr/bin/env bash
#
# Copyright 2016, Chris Smart <chris@distroguy.com>
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#     http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
#
## Test that we haven't broken things before we embarrass ourselves

## Debug
# Enable debug if DEBUG variable exists
# e.g. DEBUG=true git commit
if [[ -n "${DEBUG+DEBUG}" ]] ; then
	set -x
fi
set -o pipefail
set -o nounset

## Skip tests and scripts if SKIP_TESTS variable exists
# e.g. SKIP_TESTS=true git commit
# Note: Can also be skipped with: git commit --no-verify
if [[ -n "${SKIP_TESTS+SKIP}" ]] ; then
	exit 0
fi

## Variables
GIT_DIFF="$(git diff --name-only --cached)"
SCRIPTS=""
TESTS=""

# Create a dictionary to match types of files with specific tox tests
# e.g. structured text files (tox -e docs) or yml files (tox -e linters)
declare -A FILES=(
	["rst"]="docs"
	["yml"]="linters"
	["py"]="pep8 py27 py34"
)

## Functions
# Common error message on failure
function exit_error {
	echo -e "\npre-commit hook: ${1} failed, commit aborted."
	echo "Please take a look and retry commit."
	exit 1
}

# Look for files to be committed that match tests and prompt user
function scan_for_tests {
	for file_type in "${!FILES[@]}" ; do
		if ! grep -q "^.*\.${file_type}$" <<< "${GIT_DIFF}" ; then
			continue
		fi
		echo "Found ${file_type} files in the commit, run tests:"
		for test in ${FILES["${file_type}"]} ; do
			echo -en "\t"
			# Make sure the test is available in this repo
			if ! egrep -q "^\[testenv:${test}\]|^envlist = .*${test}" tox.ini; then
				echo "Test ${test} not found in tox.ini, skipping."
				continue
			fi
			read -rep "tox -e ${test}? [y/N]: " answer
			if [[ "${answer,,}" =~ y ]]; then
				TESTS="${TESTS:+${TESTS}, }${test}"
			fi
		done
	done
}

# Prompt user for comma separated list of any other tox tests to run
function prompt_for_tests {
	echo -en "Enter any additional tox tests, e.g.: functional, releasenotes\n\t"
	read -rep "[]: " answer
	if [[ -n "${answer}" ]]; then
		TESTS="${TESTS:+${TESTS},} ${answer}"
	fi
}

# Prompt user for comma separated list of any guides to build
function prompt_for_guides {
	echo -en "Enter any guides to build, e.g.: contributor-guide, install-guide\n\t"
	read -rep "[]: " answer
	if [[ -n "${answer}" ]]; then
		TESTS="${TESTS:+${TESTS},} build -- ${answer}"
	fi
}


# Prompt user for comma separated list of any scripts to run
function prompt_for_scripts {
	echo -en "Enter any scripts, e.g.: run_tests.sh, ~/my_test.sh\n\t"
	read -rep "[]: " answer
	if [[ -n "${answer}" ]]; then
		SCRIPTS="${SCRIPTS:+${SCRIPTS},} ${answer}"
	fi
}

## Main
# Get user input
exec < /dev/tty

# Prompt user to run tests if we have files to commit
if [[ -n "${GIT_DIFF}" ]] ; then
	read -rep "Run some tests or scripts? [y/N]: " answer
	if [[ ! "${answer,,}" =~ y ]]; then
		exit 0
	fi
else
	exit 0
fi

# Run tox tests only if we have the tox command
if hash tox 2>/dev/null ; then
	# For asettle, if we're in openstack-manuals, prompt to build guides
	if [[ "$(basename "${PWD}")" == "openstack-manuals" ]]; then
		prompt_for_guides
	fi
	# Ask if user wants to run any tox tests
	scan_for_tests
	prompt_for_tests
else
	echo "Sorry, can't find tox, skipping tests."
fi

# Ask if user wants to run any scripts
prompt_for_scripts

## Run tests
IFS=","
for test in ${TESTS} ; do
	echo -e "\npre-commit hook: running tox -e ${test}\n"
	tox -e "${test}" || exit_error "tox -e ${test}"
done

## Run scripts
# This modifies PATH to look in local dir first and runs in a subshell to
# expand any ~ in script path.
for script in ${SCRIPTS} ; do
	echo -e "\npre-commit hook: running script ${script}\n"
	( eval PATH="${PWD}:${PATH}" "${script}" ) || exit_error "script ${script}"
done

## Final message
# We only get here if everything passed or we didn't run any tests
if [[ -n "${TESTS}" || -n "${SCRIPTS}" ]] ; then
	echo -e "\nEverything passed. Great job!\n"
else
	echo -e "\nNo tests or scripts run, continuing.\n"
fi