Bumping versions in iOS apps and their repositories from the command line

Rakefile-bump_task.rb

desc 'Bump version number and commit the changes with message as the output from vrsn. Can supply argument to bump one of: major, minor, patch or build. E.g., `rake bump[major]` or `rake bump[build]`.'
task :bump,[:component] do |t, args|
    require 'open3'

    modified_file_count, stderr, status = Open3.capture3("git status --porcelain | egrep '^(M| M)' | wc -l")
    if modified_file_count.to_i > 0 then
        sh "git stash --all"
    end
  
    component = args[:component]
    if component == 'major' then
        stdout, stderr, status = Open3.capture3("vrsn major --file #{version_file}")
    elsif component == 'minor' then
        stdout, stderr, status = Open3.capture3("vrsn minor --file #{version_file}")
    elsif component == 'patch' then
        stdout, stderr, status = Open3.capture3("vrsn patch --file #{version_file}")
    elsif component == 'build' then
        stdout, stderr, status = Open3.capture3("vrsn --numeric --file #{version_file}")
    else
        fail 'Unrecognized version component.'
    end

    sh "git add #{version_file}"
    sh "git commit --message \"#{stdout}\""
    sh 'git push'
    
    if modified_file_count.to_i > 0 then
        sh "git stash pop"
    end
end