1 files changed, 59 insertions, 0 deletions
diff --git a/spec/models/context_commits_diff_spec.rb b/spec/models/context_commits_diff_spec.rb
new file mode 100644
index 00000000000..6e03ea2745e
--- /dev/null
+++ b/spec/models/context_commits_diff_spec.rb
@@ -0,0 +1,59 @@
+# frozen_string_literal: true
+
+require 'spec_helper'
+
+RSpec.describe ContextCommitsDiff do
+  let_it_be(:sha1) { "33f3729a45c02fc67d00adb1b8bca394b0e761d9" }
+  let_it_be(:sha2) { "ae73cb07c9eeaf35924a10f713b364d32b2dd34f" }
+  let_it_be(:sha3) { "0b4bc9a49b562e85de7cc9e834518ea6828729b9" }
+  let_it_be(:merge_request) { create(:merge_request) }
+  let_it_be(:project) { merge_request.project }
+  let_it_be(:mrcc1) { create(:merge_request_context_commit, merge_request: merge_request, sha: sha1, committed_date: project.commit_by(oid: sha1).committed_date) }
+  let_it_be(:mrcc2) { create(:merge_request_context_commit, merge_request: merge_request, sha: sha2, committed_date: project.commit_by(oid: sha2).committed_date) }
+  let_it_be(:mrcc3) { create(:merge_request_context_commit, merge_request: merge_request, sha: sha3, committed_date: project.commit_by(oid: sha3).committed_date) }
+
+  subject { merge_request.context_commits_diff }
+
+  describe ".empty?" do
+    it 'checks if empty' do
+      expect(subject.empty?).to be(false)
+    end
+  end
+
+  describe '.commits_count' do
+    it 'reports commits count' do
+      expect(subject.commits_count).to be(3)
+    end
+  end
+
+  describe '.diffs' do
+    it 'returns instance of Gitlab::Diff::FileCollection::Compare' do
+      expect(subject.diffs).to be_a(Gitlab::Diff::FileCollection::Compare)
+    end
+
+    it 'returns all diffs between first and last commits' do
+      expect(subject.diffs.diff_files.size).to be(5)
+    end
+  end
+
+  describe '.raw_diffs' do
+    before do
+      allow(subject).to receive(:paths).and_return(["Gemfile.zip", "files/images/6049019_460s.jpg", "files/ruby/feature.rb"])
+    end
+
+    it 'returns instance of Gitlab::Git::DiffCollection' do
+      expect(subject.raw_diffs).to be_a(Gitlab::Git::DiffCollection)
+    end
+
+    it 'returns only diff for files changed in the context commits' do
+      expect(subject.raw_diffs.size).to be(3)
+    end
+  end
+
+  describe '.diff_refs' do
+    it 'returns correct sha' do
+      expect(subject.diff_refs.head_sha).to eq(sha3)
+      expect(subject.diff_refs.base_sha).to eq("913c66a37b4a45b9769037c55c2d238bd0942d2e")
+    end
+  end
+end