Show correct size when MR diff overflowsmr-diff-size-overflow

The problem is that we often go via a diff object constructed from the diffs
stored in the DB. Those diffs, by definition, don't overflow, so we don't have
access to the 'correct' `real_size` - that is stored on the MR diff object
iself.

2 files changed, 32 insertions, 14 deletions

diff --git a/spec/features/merge_requests/diffs_spec.rb b/spec/features/merge_requests/diffs_spec.rb
index 4a6c76a5caf..b495bbef8d9 100644
--- a/spec/features/merge_requests/diffs_spec.rb
+++ b/spec/features/merge_requests/diffs_spec.rb
@@ -1,10 +1,11 @@
 require 'spec_helper'
 
 feature 'Diffs URL', js: true, feature: true do
+  let(:merge_request) { create(:merge_request) }
+  let(:project) { merge_request.source_project }
+
   before do
     login_as :admin
-    @merge_request = create(:merge_request)
-    @project = @merge_request.source_project
   end
 
   context 'when visit with */* as accept header' do
@@ -13,9 +14,9 @@ feature 'Diffs URL', js: true, feature: true do
     end
 
     it 'renders the notes' do
-      create :note_on_merge_request, project: @project, noteable: @merge_request, note: 'Rebasing with master'
+      create :note_on_merge_request, project: project, noteable: merge_request, note: 'Rebasing with master'
 
-      visit diffs_namespace_project_merge_request_path(@project.namespace, @project, @merge_request)
+      visit diffs_namespace_project_merge_request_path(project.namespace, project, merge_request)
 
       # Load notes and diff through AJAX
       expect(page).to have_css('.note-text', visible: false, text: 'Rebasing with master')
@@ -25,10 +26,9 @@ feature 'Diffs URL', js: true, feature: true do
 
   context 'when merge request has overflow' do
     it 'displays warning' do
-      allow_any_instance_of(MergeRequestDiff).to receive(:overflow?).and_return(true)
-      allow(Commit).to receive(:max_diff_options).and_return(max_files: 20, max_lines: 20)
+      allow(Commit).to receive(:max_diff_options).and_return(max_files: 3)
 
-      visit diffs_namespace_project_merge_request_path(@project.namespace, @project, @merge_request)
+      visit diffs_namespace_project_merge_request_path(project.namespace, project, merge_request)
 
       page.within('.alert') do
         expect(page).to have_text("Too many changes to show. Plain diff Email patch To preserve
diff --git a/spec/models/merge_request_spec.rb b/spec/models/merge_request_spec.rb
index 415d3e7b200..be08b96641a 100644
--- a/spec/models/merge_request_spec.rb
+++ b/spec/models/merge_request_spec.rb
@@ -199,10 +199,10 @@ describe MergeRequest, models: true do
     end
 
     context 'when there are no MR diffs' do
-      it 'delegates to the compare object' do
+      it 'delegates to the compare object, setting no_collapse: true' do
         merge_request.compare = double(:compare)
 
-        expect(merge_request.compare).to receive(:diffs).with(options)
+        expect(merge_request.compare).to receive(:diffs).with(options.merge(no_collapse: true))
 
         merge_request.diffs(options)
       end
@@ -215,15 +215,22 @@ describe MergeRequest, models: true do
     end
 
     context 'when there are MR diffs' do
-      before do
+      it 'returns the correct count' do
         merge_request.save
+
+        expect(merge_request.diff_size).to eq('105')
       end
 
-      it 'returns the correct count' do
-        expect(merge_request.diff_size).to eq(105)
+      it 'returns the correct overflow count' do
+        allow(Commit).to receive(:max_diff_options).and_return(max_files: 2)
+        merge_request.save
+
+        expect(merge_request.diff_size).to eq('2+')
       end
 
       it 'does not perform highlighting' do
+        merge_request.save
+
         expect(Gitlab::Diff::Highlight).not_to receive(:new)
 
         merge_request.diff_size
@@ -231,7 +238,7 @@ describe MergeRequest, models: true do
     end
 
     context 'when there are no MR diffs' do
-      before do
+      def set_compare(merge_request)
         merge_request.compare = CompareService.new(
           merge_request.source_project,
           merge_request.source_branch
@@ -242,10 +249,21 @@ describe MergeRequest, models: true do
       end
 
       it 'returns the correct count' do
-        expect(merge_request.diff_size).to eq(105)
+        set_compare(merge_request)
+
+        expect(merge_request.diff_size).to eq('105')
+      end
+
+      it 'returns the correct overflow count' do
+        allow(Commit).to receive(:max_diff_options).and_return(max_files: 2)
+        set_compare(merge_request)
+
+        expect(merge_request.diff_size).to eq('2+')
       end
 
       it 'does not perform highlighting' do
+        set_compare(merge_request)
+
         expect(Gitlab::Diff::Highlight).not_to receive(:new)
 
         merge_request.diff_size