Shows git diff of tracked plist files

plistGitDiff

#!/bin/bash

## @file
## Shows git diff of tracked plist files.
##
## Normally, Mac plist files are binary, so git diffs do not display. However,
## there are cases where seeing diffs is important. For example, when tracking
## changes via Mackup's git storage option.
##
## @see http://confusatory.org/post/133141617492/git-diff-for-binary-apple-property-list-files
##
## Example:
## @code
## ./plistGitDiff PATH/TO/VERSIONED/file.plist <ARGS>
## @endcode
## Where <ARGS> are any git diff args.

# Ensure we are in a git directory, because this command doesn't make sense
# otherwise.
status=$(git status 2> /dev/null)
if [ $? == 128 ]; then
  echo 'You are not in a git working tree.'
  exit 1
fi

# We set matching git config and attributes within the current project only, so
# that we can easily cleanup afterwards.
git config diff.plist.textconv "plutil -convert xml1 -o -"
echo "*.plist diff=plist" >> .gitattributes

# Check that this worked with:
# @code
# git config --get diff.plist.textconv && cat .gitattributes
# @endcode

# Accept any args for git diff. Also, --color will preserve diff colors on
# output.
diff=$(git diff --color "$@")
echo "$diff"

# Clean up our git config and attributes, to be good citizens.
git config --remove-section diff.plist
sed -i '' '/*.plist diff=plist/d' .gitattributes

git ls-files .gitattributes --error-unmatch &> /dev/null
if [ $? == 1 ]; then
  # The file is not tracked by git.
  echo 'not tracked'
  [[ $(tr -d "\r\n" < .gitattributes|wc -c) -eq 0 ]]
  if [ $? == 0 ]; then
    echo 'empty'
    # If local git attributes file is not tracked by git, and now empty, remove
    # it.
    rm .gitattributes
  fi
fi