1 files changed, 38 insertions, 0 deletions
diff --git a/spec/lib/gitlab/utils_spec.rb b/spec/lib/gitlab/utils_spec.rb
index ad2c9d7f2af..9927ad41108 100644
--- a/spec/lib/gitlab/utils_spec.rb
+++ b/spec/lib/gitlab/utils_spec.rb
@@ -127,4 +127,42 @@ describe Gitlab::Utils do
       end
     end
   end
+
+  describe '.ensure_utf8_size' do
+    context 'string is has less bytes than expected' do
+      it 'backfills string with null characters' do
+        transformed = described_class.ensure_utf8_size('a' * 10, bytes: 32)
+
+        expect(transformed.bytesize).to eq 32
+        expect(transformed).to eq ('a' * 10) + ("\0" * 22)
+      end
+    end
+
+    context 'string size is exactly the one that is expected' do
+      it 'returns original value' do
+        transformed = described_class.ensure_utf8_size('a' * 32, bytes: 32)
+
+        expect(transformed).to eq 'a' * 32
+        expect(transformed.bytesize).to eq 32
+      end
+    end
+
+    context 'when string contains a few multi-byte UTF characters' do
+      it 'backfills string with null characters' do
+        transformed = described_class.ensure_utf8_size('❤' * 6, bytes: 32)
+
+        expect(transformed).to eq '❤❤❤❤❤❤' + ("\0" * 14)
+        expect(transformed.bytesize).to eq 32
+      end
+    end
+
+    context 'when string has multiple multi-byte UTF chars exceeding 32 bytes' do
+      it 'truncates string to 32 characters and backfills it if needed' do
+        transformed = described_class.ensure_utf8_size('❤' * 18, bytes: 32)
+
+        expect(transformed).to eq ('❤' * 10) + ("\0" * 2)
+        expect(transformed.bytesize).to eq 32
+      end
+    end
+  end
 end