Put 'hidden commits' logic in CommitsHelper

app/helpers/commits_helper.rb

@@ -211,4 +211,16 @@ module CommitsHelper
   def clean(string)
     Sanitize.clean(string, remove_contents: true)
   end
+
+  def limited_commits(commits)
+    if commits.size > MergeRequestDiff::COMMITS_SAFE_SIZE
+      # Not 100% sure we need to decorate but it is idempotent and not so slow
+      [
+        commits.first(MergeRequestDiff::COMMITS_SAFE_SIZE),
+        commits.size - MergeRequestDiff::COMMITS_SAFE_SIZE
+      ]
+    else
+      [commits, 0]
+    end
+  end
 end

app/views/projects/commits/_commit_list.html.haml

+- commits, hidden = limited_commits(@commits, @project)
+- commits = Commit.decorate(commits, @project)
+
 %div.panel.panel-default
   .panel-heading
     Commits (#{@commits.count})
-  - if @commits.size > MergeRequestDiff::COMMITS_SAFE_SIZE
+  - if hidden > 0
     %ul.well-list
-      - Commit.decorate(@commits.first(MergeRequestDiff::COMMITS_SAFE_SIZE), @project).each do |commit|
+      - commits.each do |commit|
         = render "projects/commits/inline_commit", commit: commit, project: @project
       %li.warning-row.unstyled
-        other #{@commits.size - MergeRequestDiff::COMMITS_SAFE_SIZE} commits hidden to prevent performance issues.
+        other #{hidden} commits hidden to prevent performance issues.
   - else
-    %ul.well-list= render Commit.decorate(@commits, @project), project: @project
+    %ul.well-list= render commits, project: @project

app/views/projects/commits/_commits.html.haml

 - unless defined?(project)
   - project = @project
-- if @commits.size > MergeRequestDiff::COMMITS_SAFE_SIZE
-  - commits = @commits.first(MergeRequestDiff::COMMITS_SAFE_SIZE)
-  - overflow = true
-- else
-  - commits = @commits
-  - overflow = false
+
+- commits, hidden = limited_commits(@commits)
 
 - commits.group_by { |c| c.committed_date.to_date }.sort.reverse.each do |day, commits|
   .row.commits-row
@@ -20,6 +16,6 @@
         = render commits, project: project
   %hr.lists-separator
 
-- if overflow
+- if hidden > 0
   .alert.alert-warning
-    Not shown: #{@commits.size - MergeRequestDiff::COMMITS_SAFE_SIZE} more commits
+    Not shown: #{hidden} more commits