Fixing image lfs bug and also displaying text lfs

This commit, introduced in https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/23812,
fixes a problem creating a displaying image diff notes when the image
is stored in LFS. The main problem was that `Gitlab::Diff::File` was
returning an invalid valid in `text?` for this kind of files.

It also fixes a rendering problem with other LFS files, like text
ones. They LFS pointer shouldn't be shown when LFS is enabled
for the project, but they were.

2 files changed, 42 insertions, 1 deletions

diff --git a/spec/models/diff_viewer/base_spec.rb b/spec/models/diff_viewer/base_spec.rb
index c90b32c5d77..f4efe5a7b3a 100644
--- a/spec/models/diff_viewer/base_spec.rb
+++ b/spec/models/diff_viewer/base_spec.rb
@@ -58,7 +58,7 @@ describe DiffViewer::Base do
 
       context 'when the binaryness does not match' do
         before do
-          allow_any_instance_of(Blob).to receive(:binary?).and_return(true)
+          allow_any_instance_of(Blob).to receive(:binary_in_repo?).and_return(true)
         end
 
         it 'returns false' do
@@ -141,4 +141,25 @@ describe DiffViewer::Base do
       end
     end
   end
+
+  describe '#render_error_message' do
+    it 'returns nothing when no render_error' do
+      expect(viewer.render_error).to be_nil
+      expect(viewer.render_error_message).to be_nil
+    end
+
+    context 'when render_error error' do
+      before do
+        allow(viewer).to receive(:render_error).and_return(:too_large)
+      end
+
+      it 'returns an error message' do
+        expect(viewer.render_error_message).to include('it is too large')
+      end
+
+      it 'includes a "view the blob" link' do
+        expect(viewer.render_error_message).to include('view the blob')
+      end
+    end
+  end
 end
diff --git a/spec/models/diff_viewer/server_side_spec.rb b/spec/models/diff_viewer/server_side_spec.rb
index 98a8f6d4cc9..86b14b6ebf3 100644
--- a/spec/models/diff_viewer/server_side_spec.rb
+++ b/spec/models/diff_viewer/server_side_spec.rb
@@ -32,4 +32,24 @@ describe DiffViewer::ServerSide do
       end
     end
   end
+
+  describe '#render_error_reason' do
+    context 'when the diff file is stored externally' do
+      before do
+        allow(diff_file).to receive(:stored_externally?).and_return(true)
+      end
+
+      it 'returns error message if stored in LFS' do
+        allow(diff_file).to receive(:external_storage).and_return(:lfs)
+
+        expect(subject.render_error_message).to include('it is stored in LFS')
+      end
+
+      it 'returns error message if stored externally' do
+        allow(diff_file).to receive(:external_storage).and_return(:foo)
+
+        expect(subject.render_error_message).to include('it is stored externally')
+      end
+    end
+  end
 end