update ElasticAPM::SpanHelpers to use ruby2_keywords for argument del…

…egation compatibility with ruby >=3.0. add dependency on ruby2_keywords gem for ruby <2.7 compatibility. (#1294)

elastic-apm.gemspec

@@ -37,6 +37,7 @@ Gem::Specification.new do |spec|
 
   spec.add_dependency('concurrent-ruby', '~> 1.0')
   spec.add_dependency('http', '>= 3.0')
+  spec.add_runtime_dependency('ruby2_keywords')
 
   spec.require_paths = ['lib']
 end

lib/elastic_apm.rb

@@ -26,6 +26,7 @@
 require 'concurrent'
 require 'forwardable'
 require 'securerandom'
+require 'ruby2_keywords'
 
 require 'elastic_apm/version'
 require 'elastic_apm/internal_error'

lib/elastic_apm/span_helpers.rb

@@ -37,15 +37,15 @@ def __span_method_on(klass, method, name = nil, type = nil)
         type ||= Span::DEFAULT_TYPE
 
         klass.prepend(Module.new do
-          define_method(method) do |*args, &block|
+          ruby2_keywords(define_method(method) do |*args, &block|
             unless ElasticAPM.current_transaction
               return super(*args, &block)
             end
 
             ElasticAPM.with_span name.to_s, type.to_s do
               super(*args, &block)
             end
-          end
+          end)
         end)
       end
     end

spec/elastic_apm/span_helpers_spec.rb

@@ -38,6 +38,11 @@ def do_the_block_thing(&block)
         block.call
       end
       span_method :do_the_block_thing
+
+      def do_mixed_args_thing(one, two, three: nil)
+        [one, two, three]
+      end
+      span_method :do_mixed_args_thing
     end
 
     context 'on class methods', :intercept do
@@ -79,6 +84,19 @@ def do_the_block_thing(&block)
         expect(@intercepted.spans.length).to be 1
         expect(@intercepted.spans.last.name).to eq 'do_the_block_thing'
       end
+
+      it 'handles mixed positional and keyword arguments' do
+        thing = Thing.new
+
+        with_agent do
+          ElasticAPM.with_transaction do
+            thing.do_mixed_args_thing('one', 'two', three: 'three')
+          end
+        end
+
+        expect(@intercepted.spans.length).to be 1
+        expect(@intercepted.spans.last.name).to eq 'do_mixed_args_thing'
+      end
     end
   end
 end