path: root/spec/lib/gitlab/git/diff_spec.rb

require "spec_helper"

describe Gitlab::Git::Diff, seed_helper: true do
  let(:repository) { Gitlab::Git::Repository.new('default', TEST_REPO_PATH) }

  before do
    @raw_diff_hash = {
      diff: <<EOT.gsub(/^ {8}/, "").sub(/\n$/, ""),
        --- a/.gitmodules
        +++ b/.gitmodules
        @@ -4,3 +4,6 @@
         [submodule "gitlab-shell"]
         \tpath = gitlab-shell
         \turl = https://github.com/gitlabhq/gitlab-shell.git
        +[submodule "gitlab-grack"]
        +	path = gitlab-grack
        +	url = https://gitlab.com/gitlab-org/gitlab-grack.git

EOT
      new_path: ".gitmodules",
      old_path: ".gitmodules",
      a_mode: '100644',
      b_mode: '100644',
      new_file: false,
      renamed_file: false,
      deleted_file: false,
      too_large: false
    }

    @rugged_diff = repository.rugged.diff("5937ac0a7beb003549fc5fd26fc247adbce4a52e^", "5937ac0a7beb003549fc5fd26fc247adbce4a52e", paths:
                                          [".gitmodules"]).patches.first
  end

  describe 'size limit feature toggles' do
    context 'when the feature gitlab_git_diff_size_limit_increase is enabled' do
      before do
        stub_feature_flags(gitlab_git_diff_size_limit_increase: true)
      end

      it 'returns 200 KB for size_limit' do
        expect(described_class.size_limit).to eq(200.kilobytes)
      end

      it 'returns 100 KB for collapse_limit' do
        expect(described_class.collapse_limit).to eq(100.kilobytes)
      end
    end

    context 'when the feature gitlab_git_diff_size_limit_increase is disabled' do
      before do
        stub_feature_flags(gitlab_git_diff_size_limit_increase: false)
      end

      it 'returns 100 KB for size_limit' do
        expect(described_class.size_limit).to eq(100.kilobytes)
      end

      it 'returns 10 KB for collapse_limit' do
        expect(described_class.collapse_limit).to eq(10.kilobytes)
      end
    end
  end

  describe '.new' do
    context 'using a Hash' do
      context 'with a small diff' do
        let(:diff) { described_class.new(@raw_diff_hash) }

        it 'initializes the diff' do
          expect(diff.to_hash).to eq(@raw_diff_hash)
        end

        it 'does not prune the diff' do
          expect(diff).not_to be_too_large
        end
      end

      context 'using a diff that is too large' do
        it 'prunes the diff' do
          diff = described_class.new(diff: 'a' * (described_class.size_limit + 1))

          expect(diff.diff).to be_empty
          expect(diff).to be_too_large
        end
      end
    end

    context 'using a Rugged::Patch' do
      context 'with a small diff' do
        let(:diff) { described_class.new(@rugged_diff) }

        it 'initializes the diff' do
          expect(diff.to_hash).to eq(@raw_diff_hash)
        end

        it 'does not prune the diff' do
          expect(diff).not_to be_too_large
        end
      end

      context 'using a diff that is too large' do
        it 'prunes the diff' do
          expect_any_instance_of(String).to receive(:bytesize)
            .and_return(1024 * 1024 * 1024)

          diff = described_class.new(@rugged_diff)

          expect(diff.diff).to be_empty
          expect(diff).to be_too_large
        end
      end

      context 'using a collapsable diff that is too large' do
        before do
          # The patch total size is 200, with lines between 21 and 54.
          # This is a quick-and-dirty way to test this. Ideally, a new patch is
          # added to the test repo with a size that falls between the real limits.
          allow(Gitlab::Git::Diff).to receive(:size_limit).and_return(150)
          allow(Gitlab::Git::Diff).to receive(:collapse_limit).and_return(100)
        end

        it 'prunes the diff as a large diff instead of as a collapsed diff' do
          diff = described_class.new(@rugged_diff, expanded: false)

          expect(diff.diff).to be_empty
          expect(diff).to be_too_large
          expect(diff).not_to be_collapsed
        end
      end

      context 'using a large binary diff' do
        it 'does not prune the diff' do
          expect_any_instance_of(Rugged::Diff::Delta).to receive(:binary?)
            .and_return(true)

          diff = described_class.new(@rugged_diff)

          expect(diff.diff).not_to be_empty
        end
      end
    end

    context 'using a GitalyClient::Diff' do
      let(:diff) do
        described_class.new(
          Gitlab::GitalyClient::Diff.new(
            to_path: ".gitmodules",
            from_path: ".gitmodules",
            old_mode: 0100644,
            new_mode: 0100644,
            from_id: '357406f3075a57708d0163752905cc1576fceacc',
            to_id: '8e5177d718c561d36efde08bad36b43687ee6bf0',
            patch: raw_patch
          )
        )
      end

      context 'with a small diff' do
        let(:raw_patch) { @raw_diff_hash[:diff] }

        it 'initializes the diff' do
          expect(diff.to_hash).to eq(@raw_diff_hash)
        end

        it 'does not prune the diff' do
          expect(diff).not_to be_too_large
        end
      end

      context 'using a diff that is too large' do
        let(:raw_patch) { 'a' * 204800 }

        it 'prunes the diff' do
          expect(diff.diff).to be_empty
          expect(diff).to be_too_large
        end
      end

      context 'when the patch passed is not UTF-8-encoded' do
        let(:raw_patch) { @raw_diff_hash[:diff].encode(Encoding::ASCII_8BIT) }

        it 'encodes diff patch to UTF-8' do
          expect(diff.diff).to be_utf8
        end
      end
    end
  end

  describe 'straight diffs' do
    let(:options) { { straight: true } }
    let(:diffs) { described_class.between(repository, 'feature', 'master', options) }

    it 'has the correct size' do
      expect(diffs.size).to eq(24)
    end

    context 'diff' do
      it 'is an instance of Diff' do
        expect(diffs.first).to be_kind_of(described_class)
      end

      it 'has the correct new_path' do
        expect(diffs.first.new_path).to eq('.DS_Store')
      end

      it 'has the correct diff' do
        expect(diffs.first.diff).to include('Binary files /dev/null and b/.DS_Store differ')
      end
    end
  end

  describe '.between' do
    let(:diffs) { described_class.between(repository, 'feature', 'master') }
    subject { diffs }

    it { is_expected.to be_kind_of Gitlab::Git::DiffCollection }

    describe '#size' do
      subject { super().size }

      it { is_expected.to eq(1) }
    end

    context 'diff' do
      subject { diffs.first }

      it { is_expected.to be_kind_of described_class }

      describe '#new_path' do
        subject { super().new_path }

        it { is_expected.to eq('files/ruby/feature.rb') }
      end

      describe '#diff' do
        subject { super().diff }

        it { is_expected.to include '+class Feature' }
      end
    end
  end

  describe '.filter_diff_options' do
    let(:options) { { max_files: 100, invalid_opt: true } }

    context "without default options" do
      let(:filtered_options) { described_class.filter_diff_options(options) }

      it "should filter invalid options" do
        expect(filtered_options).not_to have_key(:invalid_opt)
      end
    end

    context "with default options" do
      let(:filtered_options) do
        default_options = { max_files: 5, bad_opt: 1, ignore_whitespace_change: true }
        described_class.filter_diff_options(options, default_options)
      end

      it "should filter invalid options" do
        expect(filtered_options).not_to have_key(:invalid_opt)
        expect(filtered_options).not_to have_key(:bad_opt)
      end

      it "should merge with default options" do
        expect(filtered_options).to have_key(:ignore_whitespace_change)
      end

      it "should override default options" do
        expect(filtered_options).to have_key(:max_files)
        expect(filtered_options[:max_files]).to eq(100)
      end
    end
  end

  describe '#submodule?' do
    before do
      commit = repository.lookup('5937ac0a7beb003549fc5fd26fc247adbce4a52e')
      @diffs = commit.parents[0].diff(commit).patches
    end

    it { expect(described_class.new(@diffs[0]).submodule?).to eq(false) }
    it { expect(described_class.new(@diffs[1]).submodule?).to eq(true) }
  end

  describe '#line_count' do
    it 'returns the correct number of lines' do
      diff = described_class.new(@rugged_diff)

      expect(diff.line_count).to eq(9)
    end
  end

  describe '#too_large?' do
    it 'returns true for a diff that is too large' do
      diff = described_class.new(diff: 'a' * 204800)

      expect(diff.too_large?).to eq(true)
    end

    it 'returns false for a diff that is small enough' do
      diff = described_class.new(diff: 'a')

      expect(diff.too_large?).to eq(false)
    end

    it 'returns true for a diff that was explicitly marked as being too large' do
      diff = described_class.new(diff: 'a')

      diff.too_large!

      expect(diff.too_large?).to eq(true)
    end
  end

  describe '#collapsed?' do
    it 'returns false by default even on quite big diff' do
      diff = described_class.new(diff: 'a' * 20480)

      expect(diff).not_to be_collapsed
    end

    it 'returns false by default for a diff that is small enough' do
      diff = described_class.new(diff: 'a')

      expect(diff).not_to be_collapsed
    end

    it 'returns true for a diff that was explicitly marked as being collapsed' do
      diff = described_class.new(diff: 'a')

      diff.collapse!

      expect(diff).to be_collapsed
    end
  end

  describe '#collapsed?' do
    it 'returns true for a diff that is quite large' do
      diff = described_class.new({ diff: 'a' * (described_class.collapse_limit + 1) }, expanded: false)

      expect(diff).to be_collapsed
    end

    it 'returns false for a diff that is small enough' do
      diff = described_class.new({ diff: 'a' }, expanded: false)

      expect(diff).not_to be_collapsed
    end
  end

  describe '#collapse!' do
    it 'prunes the diff' do
      diff = described_class.new(diff: "foo\nbar")

      diff.collapse!

      expect(diff.diff).to eq('')
      expect(diff.line_count).to eq(0)
    end
  end
end