1 files changed, 61 insertions, 0 deletions
diff --git a/spec/lib/gitlab/diff/diff_refs_spec.rb b/spec/lib/gitlab/diff/diff_refs_spec.rb
new file mode 100644
index 00000000000..a8173558c00
--- /dev/null
+++ b/spec/lib/gitlab/diff/diff_refs_spec.rb
@@ -0,0 +1,61 @@
+require 'spec_helper'
+
+describe Gitlab::Diff::DiffRefs, lib: true do
+  let(:project) { create(:project, :repository) }
+
+  describe '#compare_in' do
+    context 'with diff refs for the initial commit' do
+      let(:commit) { project.commit('1a0b36b3cdad1d2ee32457c102a8c0b7056fa863') }
+      subject { commit.diff_refs }
+
+      it 'returns an appropriate comparison' do
+        compare = subject.compare_in(project)
+
+        expect(compare.diff_refs).to eq(subject)
+      end
+    end
+
+    context 'with diff refs for a commit' do
+      let(:commit) { project.commit('6f6d7e7ed97bb5f0054f2b1df789b39ca89b6ff9') }
+      subject { commit.diff_refs }
+
+      it 'returns an appropriate comparison' do
+        compare = subject.compare_in(project)
+
+        expect(compare.diff_refs).to eq(subject)
+      end
+    end
+
+    context 'with diff refs for a comparison through the base' do
+      subject do
+        described_class.new(
+          start_sha: '0b4bc9a49b562e85de7cc9e834518ea6828729b9', # feature
+          base_sha: 'ae73cb07c9eeaf35924a10f713b364d32b2dd34f',
+          head_sha: 'e63f41fe459e62e1228fcef60d7189127aeba95a' # master
+        )
+      end
+
+      it 'returns an appropriate comparison' do
+        compare = subject.compare_in(project)
+
+        expect(compare.diff_refs).to eq(subject)
+      end
+    end
+
+    context 'with diff refs for a straight comparison' do
+      subject do
+        described_class.new(
+          start_sha: '0b4bc9a49b562e85de7cc9e834518ea6828729b9', # feature
+          base_sha: '0b4bc9a49b562e85de7cc9e834518ea6828729b9',
+          head_sha: 'e63f41fe459e62e1228fcef60d7189127aeba95a' # master
+        )
+      end
+
+      it 'returns an appropriate comparison' do
+        compare = subject.compare_in(project)
+
+        expect(compare.diff_refs).to eq(subject)
+      end
+    end
+  end
+end