git-walker.sh

#!/bin/bash

set -euo pipefail

changed_files=""
changed_directories=""

if [ "$BRANCH_NAME" = "master" ]; then
  echo "On master. Nothing to do."

  exit 0;
fi

# Fetch all the commits from the current branch
branch_commits=$(git log --format=%H --all --not $(git rev-list --no-walk --exclude=refs/heads/${BRANCH_NAME} --exclude=refs/remotes/origin/${BRANCH_NAME} --exclude=HEAD --all))

if [ -z "$branch_commits" ]; then
  echo "* No commit found on branch '${BRANCH_NAME}'"

  exit 0;
fi

# Collect all the files which are modified on the current branch
echo -e "\n* Looking up modified files."

for commit in $(echo $branch_commits); do
  echo ">>>>>>>>>"
  echo "${commit}"

  commit_files=$(git diff-tree --no-commit-id --name-only -r $commit;)

  echo -e "\n${commit_files}"
  echo -e "<<<<<<<<\n"

  changed_files="${changed_files} $(git diff-tree --no-commit-id --name-only -r $commit;)"
done

# Sort the files and filter out duplicates
changed_files="$(echo ${changed_files} | tr ' ' '\n' | sort -u | tr '\n' ' ')"

echo -e "\n* Files modified on branch '${BRANCH_NAME}':\n${changed_files}"

# Collect all the parent directories of the modified files
for file in $(echo $changed_files); do
  dir=$(dirname $file)

  if [ $dir = '.' ]; then continue; fi

  changed_directories="$changed_directories $dir"
done

echo -e "\n* Directories modified on branch '${BRANCH_NAME}':\n${changed_directories}"

# Run conditional actions based on the changed directories

if ( echo $changed_directories | grep 'feature' ); then
  echo "* Running feature specs"
  echo "bundle exec rake cucumber"
fi

if [[ $changed_directories =~ app\/controllers* ]]; then
  echo "* Running unit tests"
  echo "bundle exec rspec spec/controllers"
fi