Adding tests for ipynb diff transformation

spec/lib/gitlab/diff/file_spec.rb

@@ -51,6 +51,34 @@ RSpec.describe Gitlab::Diff::File do
     project.commit(branch_name).diffs.diff_files.first
   end
 
+  describe 'initialize' do
+    context 'when file is ipynb' do
+      let(:commit) { project.commit("f6b7a707") }
+      let(:diff) { commit.raw_diffs.first }
+      let(:diff_file) { described_class.new(diff, diff_refs: commit.diff_refs, repository: project.repository) }
+
+      context 'and :jupyter_clean_diffs is enabled' do
+        before do
+          stub_feature_flags(jupyter_clean_diffs: true)
+        end
+
+        it 'recreates the diff by transforming the files' do
+          expect(diff_file.diff.diff).not_to include('"| Fake')
+        end
+      end
+
+      context 'but :jupyter_clean_diffs is disabled' do
+        before do
+          stub_feature_flags(jupyter_clean_diffs: false)
+        end
+
+        it 'does not recreate the diff' do
+          expect(diff_file.diff.diff).to include('"| Fake')
+        end
+      end
+    end
+  end
+
   describe '#diff_lines' do
     let(:diff_lines) { diff_file.diff_lines }
 

spec/presenters/blob_presenter_spec.rb

@@ -121,6 +121,43 @@ RSpec.describe BlobPresenter do
     end
   end
 
+  describe '#highlight_transformed' do
+    context 'when blob is ipynb' do
+      let(:blob) { repository.blob_at('f6b7a707', 'files/ipython/markdown-table.ipynb') }
+      let(:git_blob) { blob.__getobj__ }
+
+      it 'uses md as the transformed language' do
+        expect(Gitlab::Highlight).to receive(:highlight).with('files/ipython/markdown-table.ipynb', anything, plain: nil, language: 'md')
+
+        presenter.highlight_transformed
+      end
+
+      it 'transforms the blob' do
+        expect(Gitlab::Highlight).to receive(:highlight).with('files/ipython/markdown-table.ipynb', include("%%"), plain: nil, language: 'md')
+
+        presenter.highlight_transformed
+      end
+    end
+
+    context 'when blob is other file type' do
+      let(:git_blob) { blob.__getobj__ }
+
+      before do
+        allow(git_blob)
+          .to receive(:data)
+                .and_return("line one\nline two\nline 3")
+
+        allow(blob).to receive(:language_from_gitattributes).and_return('ruby')
+      end
+
+      it 'does not transform the file' do
+        expect(Gitlab::Highlight).to receive(:highlight).with('files/ruby/regex.rb', git_blob.data, plain: nil, language: 'ruby')
+
+        presenter.highlight_transformed
+      end
+    end
+  end
+
   describe '#raw_plain_data' do
     let(:blob) { repository.blob_at('HEAD', file) }