class StructureSqlMergeDriver

git-merge-structure-sql - git merge driver for db/structure.sql in a Rails project

How to use:

$ git-merge-structure-sql --install

Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met:

Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer.
Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following disclaimer in the documentation and/or other materials provided with the distribution.

THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS “AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

Constants

VARIANTS
VERSION

Public Instance Methods

main(*argv) click to toggle source

# File lib/git-merge-structure-sql.rb, line 135
  def main(*argv)
    require 'optparse'
    require 'shellwords'

    myname = File.basename($0)
    driver_name = 'merge-structure-sql'

    banner = <<~EOF
      #{myname} - git merge driver for db/structure.sql in a Rails project #{VERSION}

      usage: #{myname} <current-file> <base-file> <other-file>
             #{myname} --install

    EOF

    install = false

    opts = OptionParser.new(banner) { |opts|
      opts.version = VERSION
      opts.summary_indent = ''
      opts.summary_width = 24

      opts.on('--install[={global|local}]',
        "Enable this merge driver in Git (default: global)") { |val|
        case install = val&.to_sym || :global
        when :global, :local
          # ok
        else
          raise OptionParser::InvalidArgument, "--install=#{val}: unknown argument"
        end
      }
    }

    files = opts.order(argv)

    if install
      global = install == :global

      git_config = ["git", "config", *("--global" if global)]

      config_file = `GIT_EDITOR=echo #{git_config.shelljoin} -e 2>/dev/null`.chomp

      puts "#{config_file}: Adding the \"#{driver_name}\" driver definition"

      system!(
        *git_config,
        "merge.#{driver_name}.name",
        "Rails structure.sql merge driver"
      )
      system!(
        *git_config,
        "merge.#{driver_name}.driver",
        "#{myname.shellescape} %A %O %B"
      )

      attributes_file =
        if global
          filename = `git config --global core.attributesfile`.chomp

          if $?.success?
            File.expand_path(filename)
          else
            [
              [File.join(ENV['XDG_CONFIG_HOME'] || '~/.config', 'git'), 'attributes'],
              ['~', '.gitattributes']
            ].find { |dir, file|
              if File.directory?(File.expand_path(dir))
                system!(*%W[
                  git config --global core.attributesfile #{File.join(dir, file)}
                ])
                break File.expand_path(file, dir)
              end
            } or raise "don't you have home?"
          end
        else
          git_dir = `git rev-parse --git-dir`.chomp

          if $?.success?
            File.expand_path(File.join('info', 'attributes'), git_dir)
          else
            raise "not in a git directory"
          end
        end

      File.open(attributes_file, 'a+') { |f|
        pattern = /^\s*structure.sql\s+(?:\S+\s+)*merge=#{Regexp.quote(driver_name)}(?:\s|$)/
        break if f.any? { |line| pattern === line }

        puts "#{attributes_file}: Registering the \"#{driver_name}\" driver for structure.sql"
        f.puts if f.pos > 0
        f.puts "structure.sql merge=#{driver_name}"
      }

      exit
    end

    unless files.size == 3
      STDERR.print opts.help
      exit 64
    end

    contents = files.map { |file| File.read(file) }

    sample = contents[0]
    if variant = VARIANTS.find { |v| v.match?(sample) }
      variant.merge!(*contents)

      files.zip(contents) do |file, content|
        File.write(file, content)
      end
    else
      STDERR.puts "#{myname}: Unsupported format; falling back to git-merge-file(1)"
    end

    exec(*%W[git merge-file -q], *files)
  rescue => e
    STDERR.puts "#{myname}: #{e.message}"
    exit 1
  end

system!(*args) click to toggle source

# File lib/git-merge-structure-sql.rb, line 131
def system!(*args)
  system(*args) or exit $?.exitstatus
end