fix(lib/string_tools) return nil if InvalidURIError

https://jira.railsc.ru/browse/PC4-16353

.gitignore

@@ -8,3 +8,5 @@
 /spec/reports/
 /tmp/
 /gemfiles
+/.idea
+Makefile.local

lib/string_tools.rb

@@ -223,6 +223,8 @@ def add_params_to_url(url, params = nil)
       uri = Addressable::URI.parse("http://#{url}") unless uri.scheme
       uri.query_values = (uri.query_values || {}).merge!(params.stringify_keys) if params.present?
       uri.normalize.to_s
+    rescue Addressable::URI::InvalidURIError
+      nil
     end
   end
   extend Uri

spec/string_tools_spec.rb

@@ -106,5 +106,13 @@
 
       it { expect(described_class.add_params_to_url(url, a: 'c')).to eq 'http://test.com/?a=c' }
     end
+
+    context 'when empty url' do
+      let(:url) { '' }
+
+      it 'return nil' do
+        expect(described_class.add_params_to_url(url, a: 'b')).to be_nil
+      end
+    end
   end
 end