fix: capture correct descriptions for RSpec one-liner examples

RSpec one-liner examples (e.g., `it { is_expected.not_to be_nil }`)
generate descriptions after execution. Updated formatter to capture
the final description in `example_finished` instead of relying on
the incomplete description at `example_started`.

Author: americodls

instrumentation/rspec/lib/opentelemetry/instrumentation/rspec/formatter.rb

@@ -68,8 +68,12 @@ def example_started(notification)
 
         def example_finished(notification)
           pop_and_finalize_span do |span|
-            result = notification.example.execution_result
+            example = notification.example
+            result = example.execution_result
 
+            # Update name and full_description for one-liner examples where description is generated after execution
+            span.name = example.description
+            span.set_attribute('rspec.example.full_description', example.full_description.to_s)
             span.set_attribute('rspec.example.result', result.status.to_s)
 
             add_exception_and_failures(span, result.exception)

instrumentation/rspec/test/opentelemetry/instrumentation/rspec/formatter_test.rb

@@ -326,6 +326,26 @@ def run_example(...)
         _(subject.events[1].attributes['exception.message']).must_equal 'another-error'
       end
     end
+
+    describe 'one-liner syntax' do
+      subject do
+        run_example do
+          it { is_expected.not_to be_nil }
+        end
+      end
+
+      it 'has a name that matches the auto-generated description' do
+        _(subject.name).must_equal 'is expected not to be nil'
+      end
+
+      it 'has a full_description attribute that includes the group description' do
+        _(subject.attributes['rspec.example.full_description']).must_equal 'group one is expected not to be nil'
+      end
+
+      it 'records when the example passes' do
+        _(subject.attributes['rspec.example.result']).must_equal 'passed'
+      end
+    end
   end
 
   describe 'using a custom tracer provider' do