Class: Homebrew::DevCmd::Extract

Inherits:
AbstractCommand show all
Defined in:
dev-cmd/extract.rb

Constant Summary collapse

BOTTLE_BLOCK_REGEX =
/  bottle (?:do.+?end|:[a-z]+)\n\n/m

Instance Attribute Summary

Attributes inherited from AbstractCommand

#args

Instance Method Summary collapse

Methods inherited from AbstractCommand

command, command_name, #initialize, parser

Constructor Details

This class inherits a constructor from Homebrew::AbstractCommand

Instance Method Details

#runvoid

This method returns an undefined value.



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# File 'dev-cmd/extract.rb', line 34

def run
  if (tap_with_name = args.named.first&.then { Tap.with_formula_name(_1) })
    source_tap, name = tap_with_name
  else
    name = args.named.first.downcase
    source_tap = CoreTap.instance
  end
  raise TapFormulaUnavailableError.new(source_tap, name) unless source_tap.installed?

  destination_tap = Tap.fetch(args.named.second)
  unless Homebrew::EnvConfig.developer?
    odie "Cannot extract formula to homebrew/core!" if destination_tap.core_tap?
    odie "Cannot extract formula to homebrew/cask!" if destination_tap.core_cask_tap?
    odie "Cannot extract formula to the same tap!" if destination_tap == source_tap
  end
  destination_tap.install unless destination_tap.installed?

  repo = source_tap.path
  pattern = if source_tap.core_tap?
    [source_tap.new_formula_path(name), repo/"Formula/#{name}.rb"].uniq
  else
    # A formula can technically live in the root directory of a tap or in any of its subdirectories
    [repo/"#{name}.rb", repo/"**/#{name}.rb"]
  end

  if args.version
    ohai "Searching repository history"
    version = args.version
    version_segments = Gem::Version.new(version).segments if Gem::Version.correct?(version)
    rev = T.let(nil, T.nilable(String))
    test_formula = T.let(nil, T.nilable(Formula))
    result = ""
    loop do
      rev = rev.nil? ? "HEAD" : "#{rev}~1"
      rev, (path,) = Utils::Git.last_revision_commit_of_files(repo, pattern, before_commit: rev)
      if rev.nil? && source_tap.shallow?
        odie <<~EOS
          Could not find #{name} but #{source_tap} is a shallow clone!
          Try again after running:
            git -C "#{source_tap.path}" fetch --unshallow
        EOS
      elsif rev.nil?
        odie "Could not find #{name}! The formula or version may not have existed."
      end

      file = repo/path
      result = Utils::Git.last_revision_of_file(repo, file, before_commit: rev)
      if result.empty?
        odebug "Skipping revision #{rev} - file is empty at this revision"
        next
      end

      test_formula = formula_at_revision(repo, name, file, rev)
      break if test_formula.nil? || test_formula.version == version

      if version_segments && Gem::Version.correct?(test_formula.version)
        test_formula_version_segments = Gem::Version.new(test_formula.version).segments
        if version_segments.length < test_formula_version_segments.length
          odebug "Apply semantic versioning with #{test_formula_version_segments}"
          break if version_segments == test_formula_version_segments.first(version_segments.length)
        end
      end

      odebug "Trying #{test_formula.version} from revision #{rev} against desired #{version}"
    end
    odie "Could not find #{name}! The formula or version may not have existed." if test_formula.nil?
  else
    # Search in the root directory of <repo> as well as recursively in all of its subdirectories
    files = Dir[repo/"{,**/}"].filter_map do |dir|
      Pathname.glob("#{dir}/#{name}.rb").find(&:file?)
    end

    if files.empty?
      ohai "Searching repository history"
      rev, (path,) = Utils::Git.last_revision_commit_of_files(repo, pattern)
      odie "Could not find #{name}! The formula or version may not have existed." if rev.nil?
      file = repo/path
      version = T.must(formula_at_revision(repo, name, file, rev)).version
      result = Utils::Git.last_revision_of_file(repo, file)
    else
      file = files.fetch(0).realpath
      rev = T.let("HEAD", T.nilable(String))
      version = Formulary.factory(file).version
      result = File.read(file)
    end
  end

  # The class name has to be renamed to match the new filename,
  # e.g. Foo version 1.2.3 becomes FooAT123 and resides in Foo@1.2.3.rb.
  class_name = Formulary.class_s(name)

  # Remove any existing version suffixes, as a new one will be added later
  name.sub!(/\b@(.*)\z\b/i, "")
  versioned_name = Formulary.class_s("#{name}@#{version}")
  result.sub!("class #{class_name} < Formula", "class #{versioned_name} < Formula")

  # Remove bottle blocks, they won't work.
  result.sub!(BOTTLE_BLOCK_REGEX, "")

  path = destination_tap.path/"Formula/#{name}@#{version.to_s.downcase}.rb"
  if path.exist?
    unless args.force?
      odie <<~EOS
        Destination formula already exists: #{path}
        To overwrite it and continue anyways, run:
          brew extract --force --version=#{version} #{name} #{destination_tap.name}
      EOS
    end
    odebug "Overwriting existing formula at #{path}"
    path.delete
  end
  ohai "Writing formula for #{name} from revision #{rev} to:", path
  path.dirname.mkpath
  path.write result
end