dabrady/post-merge

## post-merge
# Determine if the project dependencies have changed and install them if needed.
# (See below for an explanation of the `git` command being used here.)
NEW_GEMS=$(git diff-tree --name-only --no-commit-id --diff-filter=M ORIG_HEAD HEAD Gemfile Gemfile.lock)
[ -z "$NEW_GEMS" ] || (echo "Gemfile changed: installing updated dependences..." && bundle install)

# Get a list of new migration files that have been added since you last pulled.
#
# Check out `git help diff-tree` for full details, but the TL;DR is:
#   `diff-tree`: show what is different between two project trees (as opposed to
#                `diff`, which is more useful for diffing individual commits)
#   `-r`: recursively search the diff tree, rather than just the top level
#   `--name-only`: output only the paths of the changed files, instead of the diff
#   `--no-commit-id`: prevent Git from outputting commit IDs with the filenames
#   `--diff-filter=A`: only look for files that have been [A]dded
#   `--relative=db/migrate`: restrict our search to the `db/migrate` folder
#   `ORIG_HEAD`: a Git variable containing the previous HEAD commit; in this case,
#                wherever your local repo was before you pulled from the branch
#   `HEAD`: a Git variable containing the current HEAD commit; in this case,
#           the HEAD of the branch you just pulled
ADDED_MIGRATION_FILES=$(git diff-tree -r --name-only --no-commit-id --diff-filter=A --relative=db/migrate ORIG_HEAD HEAD)

# If there are any new migrations, run them.
# Otherwise, exit gracefully.
[ -z "$ADDED_MIGRATION_FILES" ] && exit 0
echo "Database structure has changed: running migrations..."
bundle exec rake db:migrate \
  && echo "Database structure successfully updated." \
  || (echo "ERROR: Failed to update local database." && exit 1)

exit 0
	# Determine if the project dependencies have changed and install them if needed.
	# (See below for an explanation of the `git` command being used here.)
	NEW_GEMS=$(git diff-tree --name-only --no-commit-id --diff-filter=M ORIG_HEAD HEAD Gemfile Gemfile.lock)
	[ -z "$NEW_GEMS" ] \|\| (echo "Gemfile changed: installing updated dependences..." && bundle install)

	# Get a list of new migration files that have been added since you last pulled.
	#
	# Check out `git help diff-tree` for full details, but the TL;DR is:
	# `diff-tree`: show what is different between two project trees (as opposed to
	# `diff`, which is more useful for diffing individual commits)
	# `-r`: recursively search the diff tree, rather than just the top level
	# `--name-only`: output only the paths of the changed files, instead of the diff
	# `--no-commit-id`: prevent Git from outputting commit IDs with the filenames
	# `--diff-filter=A`: only look for files that have been [A]dded
	# `--relative=db/migrate`: restrict our search to the `db/migrate` folder
	# `ORIG_HEAD`: a Git variable containing the previous HEAD commit; in this case,
	# wherever your local repo was before you pulled from the branch
	# `HEAD`: a Git variable containing the current HEAD commit; in this case,
	# the HEAD of the branch you just pulled
	ADDED_MIGRATION_FILES=$(git diff-tree -r --name-only --no-commit-id --diff-filter=A --relative=db/migrate ORIG_HEAD HEAD)

	# If there are any new migrations, run them.
	# Otherwise, exit gracefully.
	[ -z "$ADDED_MIGRATION_FILES" ] && exit 0
	echo "Database structure has changed: running migrations..."
	bundle exec rake db:migrate \
	&& echo "Database structure successfully updated." \
	\|\| (echo "ERROR: Failed to update local database." && exit 1)

	exit 0