1 files changed, 188 insertions, 0 deletions
diff --git a/spec/lib/gitlab/background_migration/deserialize_merge_request_diffs_and_commits_spec.rb b/spec/lib/gitlab/background_migration/deserialize_merge_request_diffs_and_commits_spec.rb
new file mode 100644
index 00000000000..18843cbe992
--- /dev/null
+++ b/spec/lib/gitlab/background_migration/deserialize_merge_request_diffs_and_commits_spec.rb
@@ -0,0 +1,188 @@
+require 'spec_helper'
+
+describe Gitlab::BackgroundMigration::DeserializeMergeRequestDiffsAndCommits do
+  describe '#perform' do
+    set(:merge_request) { create(:merge_request) }
+    set(:merge_request_diff) { merge_request.merge_request_diff }
+    let(:updated_merge_request_diff) { MergeRequestDiff.find(merge_request_diff.id) }
+
+    def diffs_to_hashes(diffs)
+      diffs.as_json(only: Gitlab::Git::Diff::SERIALIZE_KEYS).map(&:with_indifferent_access)
+    end
+
+    def quote_yaml(value)
+      MergeRequestDiff.connection.quote(YAML.dump(value))
+    end
+
+    def convert_to_yaml(merge_request_diff_id, commits, diffs)
+      MergeRequestDiff.where(id: merge_request_diff_id).update_all(
+        "st_commits = #{quote_yaml(commits)}, st_diffs = #{quote_yaml(diffs)}"
+      )
+    end
+
+    shared_examples 'updated MR diff' do
+      before do
+        convert_to_yaml(merge_request_diff.id, commits, diffs)
+
+        MergeRequestDiffCommit.delete_all
+        MergeRequestDiffFile.delete_all
+
+        subject.perform(merge_request_diff.id, merge_request_diff.id)
+      end
+
+      it 'creates correct entries in the merge_request_diff_commits table' do
+        expect(updated_merge_request_diff.merge_request_diff_commits.count).to eq(commits.count)
+        expect(updated_merge_request_diff.commits.map(&:to_hash)).to eq(commits)
+      end
+
+      it 'creates correct entries in the merge_request_diff_files table' do
+        expect(updated_merge_request_diff.merge_request_diff_files.count).to eq(expected_diffs.count)
+        expect(diffs_to_hashes(updated_merge_request_diff.raw_diffs)).to eq(expected_diffs)
+      end
+
+      it 'sets the st_commits and st_diffs columns to nil' do
+        expect(updated_merge_request_diff.st_commits_before_type_cast).to be_nil
+        expect(updated_merge_request_diff.st_diffs_before_type_cast).to be_nil
+      end
+    end
+
+    context 'when the diff IDs passed do not exist' do
+      it 'does not raise' do
+        expect { subject.perform(0, 0) }.not_to raise_exception
+      end
+    end
+
+    context 'when the merge request diff has no serialised commits or diffs' do
+      before do
+        merge_request_diff.update(st_commits: nil, st_diffs: nil)
+      end
+
+      it 'does not raise' do
+        expect { subject.perform(merge_request_diff.id, merge_request_diff.id) }
+          .not_to raise_exception
+      end
+    end
+
+    context 'processing multiple merge request diffs' do
+      let(:start_id) { described_class::MergeRequestDiff.minimum(:id) }
+      let(:stop_id) { described_class::MergeRequestDiff.maximum(:id) }
+
+      before do
+        merge_request.reload_diff(true)
+
+        convert_to_yaml(start_id, merge_request_diff.commits, merge_request_diff.diffs)
+        convert_to_yaml(stop_id, updated_merge_request_diff.commits, updated_merge_request_diff.diffs)
+
+        MergeRequestDiffCommit.delete_all
+        MergeRequestDiffFile.delete_all
+      end
+
+      context 'when BUFFER_ROWS is exceeded' do
+        before do
+          stub_const("#{described_class}::BUFFER_ROWS", 1)
+        end
+
+        it 'updates and continues' do
+          expect(described_class::MergeRequestDiff).to receive(:transaction).twice
+
+          subject.perform(start_id, stop_id)
+        end
+      end
+
+      context 'when BUFFER_ROWS is not exceeded' do
+        it 'only updates once' do
+          expect(described_class::MergeRequestDiff).to receive(:transaction).once
+
+          subject.perform(start_id, stop_id)
+        end
+      end
+    end
+
+    context 'when the merge request diff update fails' do
+      before do
+        allow(described_class::MergeRequestDiff)
+          .to receive(:update_all).and_raise(ActiveRecord::Rollback)
+      end
+
+      it 'does not add any diff commits' do
+        expect { subject.perform(merge_request_diff.id, merge_request_diff.id) }
+          .not_to change { MergeRequestDiffCommit.count }
+      end
+
+      it 'does not add any diff files' do
+        expect { subject.perform(merge_request_diff.id, merge_request_diff.id) }
+          .not_to change { MergeRequestDiffFile.count }
+      end
+    end
+
+    context 'when the merge request diff has valid commits and diffs' do
+      let(:commits) { merge_request_diff.commits.map(&:to_hash) }
+      let(:diffs) { diffs_to_hashes(merge_request_diff.merge_request_diff_files) }
+      let(:expected_diffs) { diffs }
+
+      include_examples 'updated MR diff'
+    end
+
+    context 'when the merge request diffs have binary content' do
+      let(:commits) { merge_request_diff.commits.map(&:to_hash) }
+      let(:expected_diffs) { diffs }
+
+      # The start of a PDF created by Illustrator
+      let(:binary_string) do
+        "\x25\x50\x44\x46\x2d\x31\x2e\x35\x0d\x25\xe2\xe3\xcf\xd3\x0d\x0a".force_encoding(Encoding::BINARY)
+      end
+
+      let(:diffs) do
+        [
+          {
+            'diff' => binary_string,
+            'new_path' => 'path',
+            'old_path' => 'path',
+            'a_mode' => '100644',
+            'b_mode' => '100644',
+            'new_file' => false,
+            'renamed_file' => false,
+            'deleted_file' => false,
+            'too_large' => false
+          }
+        ]
+      end
+
+      include_examples 'updated MR diff'
+    end
+
+    context 'when the merge request diff has commits, but no diffs' do
+      let(:commits) { merge_request_diff.commits.map(&:to_hash) }
+      let(:diffs) { [] }
+      let(:expected_diffs) { diffs }
+
+      include_examples 'updated MR diff'
+    end
+
+    context 'when the merge request diffs have invalid content' do
+      let(:commits) { merge_request_diff.commits.map(&:to_hash) }
+      let(:diffs) { ['--broken-diff'] }
+      let(:expected_diffs) { [] }
+
+      include_examples 'updated MR diff'
+    end
+
+    context 'when the merge request diffs are Rugged::Patch instances' do
+      let(:commits) { merge_request_diff.commits.map(&:to_hash) }
+      let(:first_commit) { merge_request.project.repository.commit(merge_request_diff.head_commit_sha) }
+      let(:diffs) { first_commit.diff_from_parent.patches }
+      let(:expected_diffs) { [] }
+
+      include_examples 'updated MR diff'
+    end
+
+    context 'when the merge request diffs are Rugged::Diff::Delta instances' do
+      let(:commits) { merge_request_diff.commits.map(&:to_hash) }
+      let(:first_commit) { merge_request.project.repository.commit(merge_request_diff.head_commit_sha) }
+      let(:diffs) { first_commit.diff_from_parent.deltas }
+      let(:expected_diffs) { [] }
+
+      include_examples 'updated MR diff'
+    end
+  end
+end