Fix transformation of regex with lookahead/lookbehind

lib/cucumber/rb_support/rb_transform.rb

@@ -39,7 +39,9 @@ def to_s
 
     private
       def convert_captures(regexp_source)
-        regexp_source.gsub(/(\()(?!\?:)/,'(?:')
+        regexp_source
+          .gsub(/(\()(?!\?[<:=!])/,'(?:')
+          .gsub(/(\(\?<)(?![=!])/,'(?:<')
       end
 
       def strip_captures(regexp_source)

spec/cucumber/rb_support/rb_transform_spec.rb

@@ -9,6 +9,26 @@ def transform(regexp)
       end
 
       describe "#to_s" do
+        it "do not touch positive lookahead captures" do
+          expect(transform(/^xy(?=z)/).to_s).to eq "xy(?=z)"
+        end
+
+        it "do not touch negative lookahead captures" do
+          expect(transform(/^xy(?!z)/).to_s).to eq "xy(?!z)"
+        end
+
+        it "do not touch positive lookbehind captures" do
+          expect(transform(/^xy(?<=z)/).to_s).to eq "xy(?<=z)"
+        end
+
+        it "do not touch negative lookbehind captures" do
+          expect(transform(/^xy(?<!z)/).to_s).to eq "xy(?<!z)"
+        end
+
+        it "converts named captures" do
+          expect(transform(/^(?<str>xyz)/).to_s).to eq "(?:<str>xyz)"
+        end
+
         it "converts captures groups to non-capture groups" do
           expect(transform(/(a|b)bc/).to_s).to eq "(?:a|b)bc"
         end