Script to find out the percentage of commits that modified sbt build files in a repository.

sbt-build-stats-git.sh

#!/bin/bash - 
#===============================================================================
#
#          FILE: sbt-build-stats-git.sh
# 
#         USAGE: ./sbt-build-stats-git.sh 
# 
#   DESCRIPTION: Script that outputs what's the percentage of commits in a codebase
#                that modified the sbt build files. It can be modified to support
#                statistics in other files.
# 
#       OPTIONS: ---
#  REQUIREMENTS: ---
#          BUGS: ---
#         NOTES: ---
#        AUTHOR: Jorge Vicente Cantero
#  ORGANIZATION: Scala Center
#       CREATED: 05/03/2018 09:32:45 PM CEST
#      REVISION:  1.0
#===============================================================================

set -o nounset                              # Treat unset variables as an error

BRANCH=${1:-master}
ALL_COMMITS_BUT_FIRST=$(git rev-list --min-parents=1 "$BRANCH")
ALL_COMMITS_BUT_FIRST_COUNT=$(echo "$ALL_COMMITS_BUT_FIRST" | wc -l)
TOTAL_COMMITS=$((ALL_COMMITS_BUT_FIRST_COUNT + 1))

count=0
for commit in $ALL_COMMITS_BUT_FIRST; do
  if git diff --name-only "$commit" "$commit"~1 | grep '.*\.sbt$' > /dev/null 2>&1; then
    count=$((count + 1))
  fi
done

PERCENTAGE=$(echo "scale=2; $count * 100 / $TOTAL_COMMITS" | bc -l)
echo "Total commits in the branch $BRANCH is $TOTAL_COMMITS"
echo "Detected changes in branch $BRANCH is $count"
echo "The percentage of commits that modify sbt build files is $PERCENTAGE"