1 files changed, 58 insertions, 0 deletions
diff --git a/spec/lib/gitlab/utils/gzip_spec.rb b/spec/lib/gitlab/utils/gzip_spec.rb
new file mode 100644
index 00000000000..5d1c62e03d3
--- /dev/null
+++ b/spec/lib/gitlab/utils/gzip_spec.rb
@@ -0,0 +1,58 @@
+# frozen_string_literal: true
+
+require 'fast_spec_helper'
+
+RSpec.describe Gitlab::Utils::Gzip do
+  before do
+    example_class = Class.new do
+      include Gitlab::Utils::Gzip
+
+      def lorem_ipsum
+        "Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod "\
+        "tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim "\
+        "veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea "\
+        "commodo consequat. Duis aute irure dolor in reprehenderit in voluptate "\
+        "velit esse cillum dolore eu fugiat nulla pariatur. Excepteur sint occaecat "\
+        "cupidatat non proident, sunt in culpa qui officia deserunt mollit anim id "\
+        "est laborum."
+      end
+    end
+
+    stub_const('ExampleClass', example_class)
+  end
+
+  subject { ExampleClass.new }
+
+  let(:sample_string) { subject.lorem_ipsum }
+  let(:compressed_string) { subject.gzip_compress(sample_string) }
+
+  describe "#gzip_compress" do
+    it "compresses data passed to it" do
+      expect(compressed_string.length).to be < sample_string.length
+    end
+
+    it "returns uncompressed data when encountering Zlib::GzipFile::Error" do
+      expect(ActiveSupport::Gzip).to receive(:compress).and_raise(Zlib::GzipFile::Error)
+
+      expect(compressed_string.length).to eq sample_string.length
+    end
+  end
+
+  describe "#gzip_decompress" do
+    let(:decompressed_string) { subject.gzip_decompress(compressed_string) }
+
+    it "decompresses encoded data" do
+      expect(decompressed_string).to eq sample_string
+    end
+
+    it "returns compressed data when encountering Zlib::GzipFile::Error" do
+      expect(ActiveSupport::Gzip).to receive(:decompress).and_raise(Zlib::GzipFile::Error)
+
+      expect(decompressed_string).not_to eq sample_string.length
+    end
+
+    it "returns unmodified data when it is determined to be uncompressed" do
+      expect(subject.gzip_decompress(sample_string)).to eq sample_string
+    end
+  end
+end