1 files changed, 66 insertions, 10 deletions
diff --git a/spec/lib/gitlab/diff/file_spec.rb b/spec/lib/gitlab/diff/file_spec.rb
index 9e5d3ab0a20..1fbb6465429 100644
--- a/spec/lib/gitlab/diff/file_spec.rb
+++ b/spec/lib/gitlab/diff/file_spec.rb
@@ -8,7 +8,9 @@ RSpec.describe Gitlab::Diff::File do
   let_it_be(:project) { create(:project, :repository) }
   let(:commit) { project.commit(sample_commit.id) }
   let(:diff) { commit.raw_diffs.first }
-  let(:diff_file) { described_class.new(diff, diff_refs: commit.diff_refs, repository: project.repository) }
+  let(:diff_file) do
+    described_class.new(diff, diff_refs: commit.diff_refs, repository: project.repository)
+  end
 
   def create_file(file_name, content)
     Files::CreateService.new(
@@ -285,18 +287,72 @@ RSpec.describe Gitlab::Diff::File do
   end
 
   describe '#old_blob and #new_blob' do
-    it 'returns blob of base commit and the new commit' do
-      items = [
-        [diff_file.new_content_sha, diff_file.new_path], [diff_file.old_content_sha, diff_file.old_path]
-      ]
+    context 'when increase_diff_file_performance is on' do
+      let(:diff_file) do
+        described_class.new(diff, diff_refs: commit.diff_refs, repository: project.repository, max_blob_size: max_blob_size)
+      end
+
+      let(:max_blob_size) { 1000 }
+
+      before do
+        stub_feature_flags(increase_diff_file_performance: true)
+      end
+
+      context 'when the blobs are truncated' do
+        let(:max_blob_size) { 10 }
+
+        it 'returns the truncated blobs' do
+          items = [
+            [diff_file.new_content_sha, diff_file.new_path], [diff_file.old_content_sha, diff_file.old_path]
+          ]
+
+          expect(project.repository).to receive(:blobs_at).with(items, blob_size_limit: max_blob_size).and_call_original
+
+          old_data = diff_file.old_blob.data
+          data = diff_file.new_blob.data
+
+          expect(old_data.size).to eq(max_blob_size)
+          expect(data.size).to eq(max_blob_size)
+        end
+      end
 
-      expect(project.repository).to receive(:blobs_at).with(items, blob_size_limit: 10.megabytes).and_call_original
+      it 'returns blob of base commit and the new commit' do
+        items = [
+          [diff_file.new_content_sha, diff_file.new_path], [diff_file.old_content_sha, diff_file.old_path]
+        ]
 
-      old_data = diff_file.old_blob.data
-      data = diff_file.new_blob.data
+        expect(project.repository).to receive(:blobs_at).with(items, blob_size_limit: max_blob_size).and_call_original
 
-      expect(old_data).to include('raise "System commands must be given as an array of strings"')
-      expect(data).to include('raise RuntimeError, "System commands must be given as an array of strings"')
+        old_data = diff_file.old_blob.data
+        data = diff_file.new_blob.data
+
+        expect(old_data).to include('raise "System commands must be given as an array of strings"')
+        expect(data).to include('raise RuntimeError, "System commands must be given as an array of strings"')
+      end
+    end
+
+    context 'when increase_diff_file_performance is off' do
+      let(:diff_file) do
+        described_class.new(diff, diff_refs: commit.diff_refs, repository: project.repository)
+      end
+
+      before do
+        stub_feature_flags(increase_diff_file_performance: false)
+      end
+
+      it 'returns blob of base commit and the new commit' do
+        items = [
+          [diff_file.new_content_sha, diff_file.new_path], [diff_file.old_content_sha, diff_file.old_path]
+        ]
+
+        expect(project.repository).to receive(:blobs_at).with(items, blob_size_limit: Gitlab::Git::Blob::MAX_DATA_DISPLAY_SIZE).and_call_original
+
+        old_data = diff_file.old_blob.data
+        data = diff_file.new_blob.data
+
+        expect(old_data).to include('raise "System commands must be given as an array of strings"')
+        expect(data).to include('raise RuntimeError, "System commands must be given as an array of strings"')
+      end
     end
   end