Module: Flatito::DiffSource

Defined in:
lib/flatito/diff_source.rb

Constant Summary collapse

NULL_BLOB = 
"0000000"

Class Method Summary collapse

Class Method Details

.blob_content(blob) ⇒ Object 



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# File 'lib/flatito/diff_source.rb', line 27

def blob_content(blob)
  return nil if blob.nil? || blob.start_with?(NULL_BLOB)

  output = IO.popen(["git", "cat-file", "-p", blob], err: File::NULL, &:read)
  return nil unless $CHILD_STATUS&.exitstatus&.zero?

  output
rescue Errno::ENOENT
  nil
end

.contents_for(file) ⇒ Object 



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# File 'lib/flatito/diff_source.rb', line 11

def contents_for(file)
  before = file.new_file ? nil : load_side(file.before_blob, file.before_path, file)
  after = file.deleted_file ? nil : load_side(file.after_blob, file.after_path, file, after_side: true)
  [before, after]
end

.load_side(blob, path, file, after_side: false) ⇒ Object 



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# File 'lib/flatito/diff_source.rb', line 17

def load_side(blob, path, file, after_side: false)
  content = blob_content(blob)
  return content if content

  content = working_tree_content(path) if after_side
  return content if content

  reconstruct_from_hunks(file, after_side: after_side)
end

.pad_until(lines, target_index) ⇒ Object 



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# File 'lib/flatito/diff_source.rb', line 66

def pad_until(lines, target_index)
  lines << "\n" while lines.size < target_index
end

.reconstruct_from_hunks(file, after_side:) ⇒ Object 



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# File 'lib/flatito/diff_source.rb', line 47

def reconstruct_from_hunks(file, after_side:)
  lines = []
  file.hunks.each do |hunk|
    target_line = after_side ? hunk.new_start : hunk.old_start
    pad_until(lines, target_line - 1)
    hunk.lines.each do |entry|
      case entry[:kind]
      when :context
        lines << entry[:text]
      when :add
        lines << entry[:text] if after_side
      when :del
        lines << entry[:text] unless after_side
      end
    end
  end
  lines.join
end

.working_tree_content(path) ⇒ Object 



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# File 'lib/flatito/diff_source.rb', line 38

def working_tree_content(path)
  return nil if path.nil? || path.empty?
  return nil unless ::File.file?(path)

  ::File.read(path)
rescue StandardError
  nil
end