fix: Do not emit logs if stopped

Previously, a no-op Logger was returned when LoggerProvider#logger was
called after the provider was stopped.

Now, when the provider is stopped, the on_emit method will return early
and not emit any log records.

This more closely follows the behavior in the TracerProvider.

logs_sdk/lib/opentelemetry/sdk/logs/logger_provider.rb

@@ -42,20 +42,15 @@ def initialize(resource: OpenTelemetry::SDK::Resources::Resource.create, log_rec
         #
         # @return [OpenTelemetry::SDK::Logs::Logger]
         def logger(name:, version: nil)
-          if @stopped
-            OpenTelemetry.logger.warn('calling LoggerProvider#logger after shutdown, a noop logger will be returned')
-            OpenTelemetry::Logs::Logger.new
-          else
-            version ||= ''
-
-            if !name.is_a?(String) || name.empty?
-              OpenTelemetry.logger.warn('LoggerProvider#logger called with an ' \
-                "invalid name. Name provided: #{name.inspect}")
-            end
+          version ||= ''
 
-            @registry_mutex.synchronize do
-              @registry[Key.new(name, version)] ||= Logger.new(name, version, self)
-            end
+          if !name.is_a?(String) || name.empty?
+            OpenTelemetry.logger.warn('LoggerProvider#logger called with an ' \
+              "invalid name. Name provided: #{name.inspect}")
+          end
+
+          @registry_mutex.synchronize do
+            @registry[Key.new(name, version)] ||= Logger.new(name, version, self)
           end
         end
 
@@ -147,6 +142,8 @@ def on_emit(timestamp: nil,
                     instrumentation_scope: nil,
                     context: nil)
 
+          return if @stopped
+
           log_record = LogRecord.new(timestamp: timestamp,
                                      observed_timestamp: observed_timestamp,
                                      severity_text: severity_text,

logs_sdk/test/opentelemetry/sdk/logs/logger_provider_test.rb

@@ -223,6 +223,20 @@ def mock_context.value(key); OpenTelemetry::Trace::Span::INVALID; end # rubocop:
         mock_log_record_processor.verify
       end
     end
+
+    it 'does not emit if the provider is stopped' do
+      logger_provider.instance_variable_set(:@stopped, true)
+      mock_log_record = Minitest::Mock.new
+
+      OpenTelemetry::SDK::Logs::LogRecord.stub :new, mock_log_record do
+        logger_provider.add_log_record_processor(mock_log_record_processor)
+        mock_log_record_processor.expect(:on_emit, nil, [mock_log_record, mock_context])
+
+        logger_provider.on_emit(**args)
+        # The verify should fail because on_emit should never call new on LogRecord
+        assert_raises(MockExpectationError) { mock_log_record_processor.verify }
+      end
+    end
   end
 
   describe 'instrument registry' do
@@ -236,28 +250,5 @@ def mock_context.value(key); OpenTelemetry::Trace::Span::INVALID; end # rubocop:
       assert_instance_of(Logs::Logger, logger)
       assert_same(logger, logger2)
     end
-
-    describe 'when stopped' do
-      it 'logs a warning' do
-        logger_provider.instance_variable_set(:@stopped, true)
-
-        OpenTelemetry::TestHelpers.with_test_logger do |log_stream|
-          logger_provider.logger(name: '')
-          assert_match(
-            /calling LoggerProvider#logger after shutdown/,
-            log_stream.string
-          )
-        end
-      end
-
-      it 'does not add a new logger to the registry' do
-        before_stopped_size = logger_provider.instance_variable_get(:@registry).keys.size
-        logger_provider.instance_variable_set(:@stopped, true)
-        logger_provider.logger(name: 'new_logger')
-        after_stopped_size = logger_provider.instance_variable_get(:@registry).keys.size
-
-        assert_equal(before_stopped_size, after_stopped_size)
-      end
-    end
   end
 end