Added Patch#removed_lines method

Author: josephbuchma

lib/git_diff_parser/patch.rb

@@ -3,6 +3,7 @@ module GitDiffParser
   class Patch
     RANGE_INFORMATION_LINE = /^@@ .+\+(?<line_number>\d+),/
     MODIFIED_LINE = /^\+(?!\+|\+)/
+    REMOVED_LINE = /^[-]/
     NOT_REMOVED_LINE = /^[^-]/
 
     attr_accessor :file, :body, :secure_hash
@@ -76,6 +77,27 @@ def changed_lines
       end
     end
 
+    def removed_lines
+      line_number = 0
+
+      lines.each_with_index.inject([]) do |lines, (content, patch_position)|
+        case content
+        when RANGE_INFORMATION_LINE
+          line_number = Regexp.last_match[:line_number].to_i
+        when REMOVED_LINE
+          line = Line.new(
+            content: content,
+            number: line_number,
+            patch_position: patch_position
+          )
+          lines << line
+          line_number += 1
+        end
+
+        lines
+      end
+    end
+
     # @return [Array<Integer>] changed line numbers
     def changed_line_numbers
       changed_lines.map(&:number)