test: Improve tests

spec/support/string_clean_multiline.rb

@@ -0,0 +1,10 @@
+# frozen_string_literal: true
+
+module StringCleanMultiline
+  refine String do
+    def clean_multiline
+      # Get rid of newlines and indentation spaces
+      strip.gsub(/\s*\n\s*/, "")
+    end
+  end
+end