Merge branch 'side-by-side-unfold' into 'master'

Add unfold links for Side-by-Side view

## What does this MR do?

Add unfold links for Side-by-Side view and refactor some diff related code

## What are the relevant issue numbers?

Closes #3877 

## Does this MR meet the acceptance criteria?

- [x] [CHANGELOG](https://gitlab.com/gitlab-org/gitlab-ce/blob/master/CHANGELOG) entry added
- [x] [Documentation created/updated](https://gitlab.com/gitlab-org/gitlab-ce/blob/master/doc/development/doc_styleguide.md)
- [x] API support added
- Tests
  - [x] Added for this feature/bug
  - [x] All builds are passing
- [x] Conform by the [style guides](https://gitlab.com/gitlab-org/gitlab-ce/blob/master/CONTRIBUTING.md#style-guides)
- [x] Branch has no merge conflicts with `master` (if you do - rebase it please)
- [x] [Squashed related commits together](https://git-scm.com/book/en/Git-Tools-Rewriting-History#Squashing-Commits)

See merge request !5415

6 files changed, 11 insertions, 18 deletions

diff --git a/app/views/projects/diffs/_content.html.haml b/app/views/projects/diffs/_content.html.haml
index a1b071f130c..d37961c4e40 100644
--- a/app/views/projects/diffs/_content.html.haml
+++ b/app/views/projects/diffs/_content.html.haml
@@ -13,7 +13,7 @@
       .nothing-here-block.diff-collapsed{data: { diff_for_path: url } }
         This diff is collapsed. Click to expand it.
     - elsif diff_file.diff_lines.length > 0
-      - if diff_view == 'parallel'
+      - if diff_view == :parallel
         = render "projects/diffs/parallel_view", diff_file: diff_file, project: project, blob: blob
       - else
         = render "projects/diffs/text_file", diff_file: diff_file
diff --git a/app/views/projects/diffs/_diffs.html.haml b/app/views/projects/diffs/_diffs.html.haml
index ebaf939f930..62aff36aadd 100644
--- a/app/views/projects/diffs/_diffs.html.haml
+++ b/app/views/projects/diffs/_diffs.html.haml
@@ -1,6 +1,6 @@
 - show_whitespace_toggle = local_assigns.fetch(:show_whitespace_toggle, true)
 - diff_files = diffs.diff_files
-- if diff_view == 'parallel'
+- if diff_view == :parallel
   - fluid_layout true
 
 .content-block.oneline-block.files-changed
diff --git a/app/views/projects/diffs/_line.html.haml b/app/views/projects/diffs/_line.html.haml
index 4d3af905b58..2d6a370b848 100644
--- a/app/views/projects/diffs/_line.html.haml
+++ b/app/views/projects/diffs/_line.html.haml
@@ -4,8 +4,7 @@
 %tr.line_holder{ plain ? { class: type} : { class: type, id: line_code } }
   - case type
   - when 'match'
-    = render "projects/diffs/match_line", { line: line.text,
-      line_old: line.old_pos, line_new: line.new_pos, bottom: false, new_file: diff_file.new_file }
+    = diff_match_line line.old_pos, line.new_pos, text: line.text
   - when 'nonewline'
     %td.old_line.diff-line-num
     %td.new_line.diff-line-num
diff --git a/app/views/projects/diffs/_match_line.html.haml b/app/views/projects/diffs/_match_line.html.haml
deleted file mode 100644
index d6dddd97879..00000000000
--- a/app/views/projects/diffs/_match_line.html.haml
+++ /dev/null
@@ -1,7 +0,0 @@
-%td.old_line.diff-line-num{data: {linenumber: line_old},
- class: [unfold_bottom_class(bottom), unfold_class(!new_file)]}
-  \...
-%td.new_line.diff-line-num{data: {linenumber: line_new},
- class: [unfold_bottom_class(bottom), unfold_class(!new_file)]}
-  \...
-%td.line_content.match= line
diff --git a/app/views/projects/diffs/_parallel_view.html.haml b/app/views/projects/diffs/_parallel_view.html.haml
index 7f30faa20d8..28aad3f4725 100644
--- a/app/views/projects/diffs/_parallel_view.html.haml
+++ b/app/views/projects/diffs/_parallel_view.html.haml
@@ -1,14 +1,15 @@
 / Side-by-side diff view
 %div.text-file.diff-wrap-lines.code.file-content.js-syntax-highlight{ data: diff_view_data }
   %table
+    - last_line = 0
     - diff_file.parallel_diff_lines.each do |line|
       - left = line[:left]
       - right = line[:right]
+      - last_line = right.new_pos if right
       %tr.line_holder.parallel
         - if left
           - if left.meta?
-            %td.old_line.diff-line-num.empty-cell
-            %td.line_content.parallel.match= left.text
+            = diff_match_line left.old_pos, nil, text: left.text, view: :parallel
           - else
             - left_line_code = diff_file.line_code(left)
             - left_position = diff_file.position(left)
@@ -21,8 +22,7 @@
 
         - if right
           - if right.meta?
-            %td.old_line.diff-line-num.empty-cell
-            %td.line_content.parallel.match= left.text
+            = diff_match_line nil, right.new_pos, text: left.text, view: :parallel
           - else
             - right_line_code = diff_file.line_code(right)
             - right_position = diff_file.position(right)
@@ -37,3 +37,5 @@
         - discussion_left, discussion_right = parallel_diff_discussions(left, right, diff_file)
         - if discussion_left || discussion_right
           = render "discussions/parallel_diff_discussion", discussion_left: discussion_left, discussion_right: discussion_right
+    - if !diff_file.new_file && last_line > 0
+      = diff_match_line last_line, last_line, bottom: true, view: :parallel
diff --git a/app/views/projects/diffs/_text_file.html.haml b/app/views/projects/diffs/_text_file.html.haml
index 5970b9abf2b..ab5463ba89d 100644
--- a/app/views/projects/diffs/_text_file.html.haml
+++ b/app/views/projects/diffs/_text_file.html.haml
@@ -15,6 +15,5 @@
       - if discussion
         = render "discussions/diff_discussion", discussion: discussion
 
-  - if last_line > 0
-    = render "projects/diffs/match_line", { line: "",
-      line_old: last_line, line_new: last_line, bottom: true, new_file: diff_file.new_file }
+  - if !diff_file.new_file && last_line > 0
+    = diff_match_line last_line, last_line, bottom: true