Implement diff viewers

2 files changed, 186 insertions, 0 deletions

diff --git a/spec/models/diff_viewer/base_spec.rb b/spec/models/diff_viewer/base_spec.rb
new file mode 100644
index 00000000000..3755f4a56f3
--- /dev/null
+++ b/spec/models/diff_viewer/base_spec.rb
@@ -0,0 +1,150 @@
+require 'spec_helper'
+
+describe DiffViewer::Base, model: true do
+  include FakeBlobHelpers
+
+  let(:project) { create(:project, :repository) }
+  let(:commit) { project.commit('570e7b2abdd848b95f2f578043fc23bd6f6fd24d') }
+  let(:diff_file) { commit.diffs.diff_file_with_new_path('files/ruby/popen.rb') }
+
+  let(:viewer_class) do
+    Class.new(described_class) do
+      include DiffViewer::ServerSide
+
+      self.extensions = %w(jpg)
+      self.binary = true
+      self.collapse_limit = 1.megabyte
+      self.size_limit = 5.megabytes
+    end
+  end
+
+  let(:viewer) { viewer_class.new(diff_file) }
+
+  describe '.can_render?' do
+    context 'when the extension is supported' do
+      let(:commit) { project.commit('2f63565e7aac07bcdadb654e253078b727143ec4') }
+      let(:diff_file) { commit.diffs.diff_file_with_new_path('files/images/6049019_460s.jpg') }
+
+      context 'when the binaryness matches' do
+        it 'returns true' do
+          expect(viewer_class.can_render?(diff_file)).to be_truthy
+        end
+      end
+
+      context 'when the binaryness does not match' do
+        before do
+          allow(diff_file.old_blob).to receive(:binary?).and_return(false)
+          allow(diff_file.new_blob).to receive(:binary?).and_return(false)
+        end
+
+        it 'returns false' do
+          expect(viewer_class.can_render?(diff_file)).to be_falsey
+        end
+      end
+    end
+
+    context 'when the file type is supported' do
+      let(:commit) { project.commit('1a0b36b3cdad1d2ee32457c102a8c0b7056fa863') }
+      let(:diff_file) { commit.diffs.diff_file_with_new_path('LICENSE') }
+
+      before do
+        viewer_class.file_types = %i(license)
+        viewer_class.binary = false
+      end
+
+      context 'when the binaryness matches' do
+        it 'returns true' do
+          expect(viewer_class.can_render?(diff_file)).to be_truthy
+        end
+      end
+
+      context 'when the binaryness does not match' do
+        before do
+          allow(diff_file.old_blob).to receive(:binary?).and_return(true)
+          allow(diff_file.new_blob).to receive(:binary?).and_return(true)
+        end
+
+        it 'returns false' do
+          expect(viewer_class.can_render?(diff_file)).to be_falsey
+        end
+      end
+    end
+
+    context 'when the extension and file type are not supported' do
+      it 'returns false' do
+        expect(viewer_class.can_render?(diff_file)).to be_falsey
+      end
+    end
+
+    context 'when the file was renamed and only the old blob is supported' do
+      let(:commit) { project.commit('2f63565e7aac07bcdadb654e253078b727143ec4') }
+      let(:diff_file) { commit.diffs.diff_file_with_new_path('files/images/6049019_460s.jpg') }
+
+      before do
+        allow(diff_file).to receive(:renamed_file?).and_return(true)
+        allow(diff_file.new_blob).to receive(:extension).and_return('jpeg')
+      end
+
+      it 'returns false' do
+        expect(viewer_class.can_render?(diff_file)).to be_falsey
+      end
+    end
+  end
+
+  describe '#collapsed?' do
+    context 'when the combined blob size is larger than the collapse limit' do
+      before do
+        allow(diff_file.old_blob).to receive(:raw_size).and_return(512.kilobytes)
+        allow(diff_file.new_blob).to receive(:raw_size).and_return(513.kilobytes)
+      end
+
+      it 'returns true' do
+        expect(viewer.collapsed?).to be_truthy
+      end
+    end
+
+    context 'when the combined blob size is smaller than the collapse limit' do
+      it 'returns false' do
+        expect(viewer.collapsed?).to be_falsey
+      end
+    end
+  end
+
+  describe '#too_large?' do
+    context 'when the combined blob size is larger than the size limit' do
+      before do
+        allow(diff_file.old_blob).to receive(:raw_size).and_return(2.megabytes)
+        allow(diff_file.new_blob).to receive(:raw_size).and_return(4.megabytes)
+      end
+
+      it 'returns true' do
+        expect(viewer.too_large?).to be_truthy
+      end
+    end
+
+    context 'when the blob size is smaller than the size limit' do
+      it 'returns false' do
+        expect(viewer.too_large?).to be_falsey
+      end
+    end
+  end
+
+  describe '#render_error' do
+    context 'when the combined blob size is larger than the size limit' do
+      before do
+        allow(diff_file.old_blob).to receive(:raw_size).and_return(2.megabytes)
+        allow(diff_file.new_blob).to receive(:raw_size).and_return(4.megabytes)
+      end
+
+      it 'returns :too_large' do
+        expect(viewer.render_error).to eq(:too_large)
+      end
+    end
+
+    context 'when the combined blob size is smaller than the size limit' do
+      it 'returns nil' do
+        expect(viewer.render_error).to be_nil
+      end
+    end
+  end
+end
diff --git a/spec/models/diff_viewer/server_side_spec.rb b/spec/models/diff_viewer/server_side_spec.rb
new file mode 100644
index 00000000000..2d926e06936
--- /dev/null
+++ b/spec/models/diff_viewer/server_side_spec.rb
@@ -0,0 +1,36 @@
+require 'spec_helper'
+
+describe DiffViewer::ServerSide, model: true do
+  let(:project) { create(:project, :repository) }
+  let(:commit) { project.commit('570e7b2abdd848b95f2f578043fc23bd6f6fd24d') }
+  let(:diff_file) { commit.diffs.diff_file_with_new_path('files/ruby/popen.rb') }
+
+  let(:viewer_class) do
+    Class.new(DiffViewer::Base) do
+      include DiffViewer::ServerSide
+    end
+  end
+
+  subject { viewer_class.new(diff_file) }
+
+  describe '#prepare!' do
+    it 'loads all diff file data' do
+      expect(diff_file.old_blob).to receive(:load_all_data!)
+      expect(diff_file.new_blob).to receive(:load_all_data!)
+
+      subject.prepare!
+    end
+  end
+
+  describe '#render_error' do
+    context 'when the diff file is stored externally' do
+      before do
+        allow(diff_file).to receive(:stored_externally?).and_return(true)
+      end
+
+      it 'return :server_side_but_stored_externally' do
+        expect(subject.render_error).to eq(:server_side_but_stored_externally)
+      end
+    end
+  end
+end