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

Rakefile-bump_task.rb

desc 'Bump version number, commit the changes, and tag that commit. 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'

    sh "git stash --all"

    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 tag `vrsn --read --file #{version_file}`+`vrsn --read --numeric --file #{version_file}`"
    sh "git stash pop"
end