git-random-commits

#!/bin/bash

VERSION="0.0.1 20170531"
DESCRIPTION="Utility to generate random commits in CURRENT Git repository"
COPYRIGHT="GPLv3 - Diego Lago <diego.lago.gonzalez@gmail.com>"

DRY_RUN=
ONLY_GENERATE_FILE_NAMES=
INIT_GIT=
USE_DIRECTORIES=
COMMIT_COUNT=1
FILES_PER_COMMIT=1
VERBOSE=
BRANCH=

COMMIT_RANDOM_MESSAGE_URL=http://whatthecommit.com/index.txt
COMMIT_RANDOM_MESSAGE_FILE=

FILENAMES=(main manager component controller action utils crypt build security sound driver
           parser json xml view serializer icon system network config base dashboard login
           widget vendor bootstrap highlight ajax core default store language loader writer
           reader model test lint helper package notification navigator message router admin
           setting environment module service about index home branch release project nav
           timeline commit bar api http https user auth mock humans robots lock blocker url
           www library lib sql database table tmp bin binary function procedure receiver
           sender post pre merger chart reviewer task monitor detail feed schedule revert
           kernel filter cache fixture requirement subversion git repository static dynamic
           command group ignore import export watch compile launch daemon execute process
           resolve option rebase automerge automatic clean install uninstall seed preseed
           operation build update upgrade purge multibuild setup link issue maker tree file
           path full empty daily weekly monthly yearly tag operate run kill freeze delete
           remove undelete notify common report extension fleet mail infrastructure metrics
           tool unlock degrade sandbox packager query agent status fast slow linux debug)

FILENAMES_COUNT=${#FILENAMES[@]}

EXTENSIONS=(.txt .h .c .hpp .cpp .d .py .rb .sh .s .md .pdf .csv .gif .jpg .svg .css .html
            .php .js .png .so .pl .ttf .yaml .json .xml .log .am .in .mk .tar .gz .tar.gz
            .m4 .go .asm .java .hxx .cxx .di .lib .ini .cfg .conf .pm .url .zip .ada .cc
            .dtd .idl .lisp .o .obj .pas .res .ui .uml .dat .ac .dts .sys .rar .xz .boot
            .S .doc .docx .xls .xlsx .ppt .pptx .ps .kt .kts .jsp .do .rss .cgi .atom .cs
            .dtl .tcl .bcpl .r .sass .less .b .bf .lol .lols .mal .mb .bf .7z .snd .wav
            .mp3 .aac .ogg .ogv .mkv .app .apk .cda .db2 .db3 .sqlite .raw .vob .info .nfo)

EXTENSIONS_COUNT=${#EXTENSIONS[@]}

USER_NAMES=(James David Christopher George Ronald John Richard Daniel Kenneth Antony Robert
	        Charles Paul Steven Kevin Michael Joseph Mark Edward Jason William Thomas Donald
	        Brian Jeff Mary Jennifer Lisa Sandra Michelle Patricia Maria Nancy Donna Laura
	        Linda Susan Karen Carol Sarah Barbara Margaret Betty Ruth Kimberly Elisabeth
	        Dorothy Helen Sharon Deborah)

NAME_PATTERN="XNAMEX"
UPPERNAME_PATTERN="XUPPERNAMEX"

# TODO: Process XNUM([0-9,]*)X patterns
NUM_PATTERN='XNUM([0-9,]*)X'

function error() {
	echo "ERROR: $1" 1>&2
	exit $2
}

function verbose() {
	if [ ! -z "$VERBOSE" ]; then
		echo "$*" 1>&2
	fi
}

function join_by() {
	local IFS="$1"
	shift
	echo "$*"
}

function is_dry_run() {
	test ! -z "$DRY_RUN"
}

function get_random_user_name() {
	local c=${#USER_NAMES[@]}
	local r=$((RANDOM % c))
	echo ${USER_NAMES[$r]}
}

function get_random_commit_message_from_url() {
	curl -s "$COMMIT_RANDOM_MESSAGE_URL"
}

function get_random_commit_message_from_file() {
	local message_count=$(wc -l "$COMMIT_RANDOM_MESSAGE_FILE" | cut -d' ' -f1)
	local r=$((RANDOM % message_count))
	r=$((r+1))  # sed don't use a zero-based line index when accessing to files.
	sed --quiet "${r}p" "$COMMIT_RANDOM_MESSAGE_FILE"
}

function get_random_commit_message() {
	local username=$(get_random_user_name)
	if [ ! -z "$COMMIT_RANDOM_MESSAGE_FILE" ]; then
		get_random_commit_message_from_file | sed -e "s/XNAMEX/$username/" -e "s/XUPPERNAMEX/${username^^}/"
	else
		get_random_commit_message_from_url | sed -e "s/XNAMEX/$username/" -e "s/XUPPERNAMEX/${username^^}/"
	fi
	
}

function get_random_file_name() {
	local r=$((RANDOM % FILENAMES_COUNT))
	echo ${FILENAMES[$r]}
}

function get_random_extension() {
	local r=$((RANDOM % EXTENSIONS_COUNT))
	echo ${EXTENSIONS[$r]}
}

function construct_random_filename() {
	local part_count_prob=(1 1 1 1 2 2 2 2 3 3)
	local c=${#part_count_prob[@]}
	local r=$((RANDOM % $c))
	local parts=${part_count_prob[$r]}
	local filenames=()
	local dir=
	for n in $(seq 1 $parts); do
		if [ ! -z "$USE_DIRECTORIES" ]; then
			dir="$(get_random_file_name)/"
		fi
		filenames+=($(get_random_file_name))
	done
	echo "$dir$(join_by '_' ${filenames[*]})$(get_random_extension)"
}

function show_file_names_and_extensions() {
	echo "-----Base File Names-----"
	echo ${FILENAMES[*]}
	echo "-----Base Extensions-----"
	echo ${EXTENSIONS[*]}
}

function show_help() {
	cat <<EOF
$(basename -- $0) -- $DESCRIPTION
$COPYRIGHT
Usage: $(basename -- $0) [options]
Options:
  -b BRANCH    Use BRANCH to commit (default is current branch; create if needed).
  -d           Use random directories to create files.
  -D           Dry run mode (do not commit).
  -f FILE      Use FILE as the file where commit messages are loaded from.
  -g           Only generate (and print) random file names.
  -i           Init Git repository before making any commit.
  -l           List file names and extensions used to generate random file names.
  -n N         Generate N number of commits (default: $COMMIT_COUNT).
  -N N         Use N files to create the commit (default: $FILES_PER_COMMIT).
  -v           Be verbose.
  -h           Show this help and exit.
EOF
}

function process_options() {
	while getopts ":b:f:ghidDln:N:v" opt; do
		case "$opt" in
			b)
				BRANCH="$OPTARG"
			;;
			d)
				USE_DIRECTORIES=yes
			;;
			D)
				DRY_RUN=yes
			;;
			f)
				COMMIT_RANDOM_MESSAGE_FILE="$OPTARG"
			;;
			g)
				ONLY_GENERATE_FILE_NAMES=yes
			;;
			h)
				show_help
				exit 1
			;;
			i)
				INIT_GIT=yes
			;;
			l)
				show_file_names_and_extensions
				exit 0
			;;
			n)
				COMMIT_COUNT="$OPTARG"
			;;
			N)
				FILES_PER_COMMIT="$OPTARG"
			;;
			v)
				VERBOSE=yes
			;;
			\?)
				error "Invalid option: -$OPTARG" 1
			;;
			:)
				error "Option -$OPTARG requires an argument." 1
			;;
		esac
	done
}

function check_options() {
	# TODO: Check all options.
	if [ ! -z "$COMMIT_RANDOM_MESSAGE_FILE" -a ! -f "$COMMIT_RANDOM_MESSAGE_FILE" ]; then
		error "Random commit messages file is not found: $COMMIT_RANDOM_MESSAGE_FILE" 1
	fi
}

function init_git_repository_if_requested() {
	if [ ! -z "$INIT_GIT" ]; then
		verbose " ! Initializing Git repository..."
		if is_dry_run; then
			echo "   git init"
		else
			git init
		fi
	fi
}

function generate_commit_and_make_the_commit() {
	local filepath=
	local commit_message=$(get_random_commit_message)
	if is_dry_run; then
		if [ ! -z "$BRANCH" ]; then
			verbose " - Checkout branch $BRANCH..."
			echo "   git checkout -b $BRANCH"
		fi
		for n in $(seq 1 $FILES_PER_COMMIT); do
			filepath=$(construct_random_filename)
			verbose " + Add file to commit: $filepath"
			echo "   git add $filepath"
		done
		verbose " > Commiting with message \"$commit_message\"..."
		echo "   git commit --message "\"$commit_message\"""
	else
		if [ ! -z "$BRANCH" ]; then
			verbose "  - Checkout branch $BRANCH..."
			git checkout -b "$BRANCH"
		fi
		for n in $(seq 1 $FILES_PER_COMMIT); do
			filepath=$(construct_random_filename)
			if ! mkdir -p $(dirname -- $filepath); then
				error "Cannot create directory: $(dirname -- $filepath)" 1
			fi
			if ! touch $filepath; then
				error "Cannot touch file: $filepath" 1
			fi
			if ! git add $filepath; then
				error "Cannot add file to Git repository: $filepath" 1
			fi
			verbose " + Add file to commit: $filepath"
		done
		verbose " > Commiting with message '$commit_message'..."
		if ! git commit --message "$commit_message"; then
			error "Cannot commit in Git repository." 1
		fi
		if [ ! -z "$BRANCH" ]; then
			git checkout -
		fi
	fi
}

function generate_random_filenames() {
	for n in $(seq 1 $FILES_PER_COMMIT); do
		construct_random_filename
	done
}

function main() {
	process_options	"$@"
	shift $OPTIND
	check_options
	verbose "$(basename -- $0) $VERSION - $DESCRIPTION"
	verbose "$COPYRIGHT"
	if is_dry_run; then
		verbose "*** DRY RUN Mode ***"
	fi
	if [ ! -z "$ONLY_GENERATE_FILE_NAMES" ]; then
		generate_random_filenames
	else
		verbose "Creating $COMMIT_COUNT random commits..."
		if [ -z "$COMMIT_RANDOM_MESSAGE_FILE" ]; then
			verbose "Using '$COMMIT_RANDOM_MESSAGE_URL' to generate random commit messages."
		else
			verbose "Using '$COMMIT_RANDOM_MESSAGE_FILE' to generate random commit messages."
		fi
		init_git_repository_if_requested
		for i in $(seq 1 $COMMIT_COUNT); do
			generate_commit_and_make_the_commit
		done
	fi
	verbose "Done."
}

main "$@"