Whoops, forgot to add files

1 files changed, 85 insertions, 0 deletions

diff --git a/lib/gitlab/diff/inline_diff_marker.rb b/lib/gitlab/diff/inline_diff_marker.rb
new file mode 100644
index 00000000000..4bb755e3d3d
--- /dev/null
+++ b/lib/gitlab/diff/inline_diff_marker.rb
@@ -0,0 +1,85 @@
+module Gitlab
+  module Diff
+    class InlineDiffMarker
+      attr_accessor :raw_line, :rich_line
+
+      def initialize(raw_line, rich_line = raw_line)
+        @raw_line = raw_line
+        @rich_line = rich_line
+      end
+
+      def mark(line_inline_diffs)
+        offset = 0
+        line_inline_diffs.each do |inline_diff_range|
+          inline_diff_positions = position_mapping[inline_diff_range]
+          marker_ranges = collapse_ranges(inline_diff_positions)
+
+          marker_ranges.each do |range|
+            offset = insert_around_range(rich_line, range, "<span class='idiff'>", "</span>", offset)
+          end
+        end
+
+        rich_line
+      end
+
+      def position_mapping
+        @position_mapping ||= begin
+          mapping = []
+          raw_pos = 0
+          rich_pos = 0
+          (0..raw_line.length).each do |raw_pos|
+            raw_char = raw_line[raw_pos]
+            rich_char = rich_line[rich_pos]
+
+            while rich_char == '<'
+              until rich_char == '>'
+                rich_pos += 1
+                rich_char = rich_line[rich_pos]
+              end
+
+              rich_pos += 1
+              rich_char = rich_line[rich_pos]
+            end
+
+            mapping[raw_pos] = rich_pos
+
+            rich_pos += 1
+          end
+
+          mapping
+        end
+      end
+
+      def collapse_ranges(positions)
+        return [] if positions.empty?
+        ranges = []
+
+        start = prev = positions[0]
+        range = start..prev
+        positions[1..-1].each do |pos|
+          if pos == prev + 1
+            range = start..pos
+            prev = pos
+          else
+            ranges << range
+            start = prev = pos
+            range = start..prev
+          end
+        end
+        ranges << range
+
+        ranges
+      end
+
+      def insert_around_range(text, range, before, after, offset = 0)
+        text.insert(offset + range.begin, before)
+        offset += before.length
+
+        text.insert(offset + range.end + 1, after)
+        offset += after.length
+
+        offset
+      end
+    end
+  end
+end