don't create new update processor is already started

Author: jsonbailey

lib/ldclient-rb/impl/datasource/null_processor.rb

@@ -7,8 +7,6 @@ module DataSource
       # A minimal UpdateProcessor implementation used when the SDK is in offline mode
       # or daemon (LDD) mode. It does nothing except mark itself as initialized.
       #
-      # @private
-      #
       class NullUpdateProcessor
         include LaunchDarkly::Interfaces::DataSource
 

lib/ldclient-rb/impl/datasystem/fdv1.rb

@@ -12,8 +12,6 @@ module DataSystem
       # FDv1 wires the existing v1 data source and store behavior behind the
       # generic DataSystem surface.
       #
-      # @private
-      #
       class FDv1
         include LaunchDarkly::Impl::DataSystem
 
@@ -63,7 +61,7 @@ def initialize(sdk_key, config)
           # Ensure v1 processors can find the sink via config for status updates
           @config.data_source_update_sink = @data_source_update_sink
 
-          # Update processor created in start(), because it needs the ready event
+          # Update processor created in start()
           @update_processor = nil
 
           # Diagnostic accumulator provided by client for streaming metrics
@@ -74,15 +72,20 @@ def initialize(sdk_key, config)
         # Starts the v1 update processor and returns immediately. The returned event
         # will be set by the processor upon first successful initialization or upon permanent failure.
         #
+        # If called multiple times, returns the same event as the first call. The update
+        # processor is created only once, and subsequent calls delegate to the processor's
+        # own start method which handles multiple invocations.
+        #
         # @return [Concurrent::Event] Event that will be set when initialization is complete
         #
         def start
-          @update_processor = make_update_processor
+          @update_processor ||= make_update_processor
           @update_processor.start
         end
 
         #
-        # Halts the data system, stopping the update processor and shutting down the executor.
+        # Halts the data system, stopping the update processor and shutting down the executor,
+        # making the data system no longer usable.
         #
         # @return [void]
         #

lib/ldclient-rb/impl/integrations/test_data/test_data_source.rb

@@ -5,7 +5,6 @@ module LaunchDarkly
   module Impl
     module Integrations
       module TestData
-        # @private
         class TestDataSource
           include LaunchDarkly::Interfaces::DataSource
 

spec/impl/datasystem/fdv1_spec.rb

@@ -95,6 +95,28 @@ module DataSystem
               expect(ready_event).to be_a(Concurrent::Event)
             end
           end
+
+          it "returns the same event on multiple calls" do
+            first_event = subject.start
+            second_event = subject.start
+            third_event = subject.start
+
+            expect(second_event).to be(first_event)
+            expect(third_event).to be(first_event)
+          end
+
+          it "does not create a new processor on subsequent calls" do
+            processor = MockUpdateProcessor.new
+            allow(subject).to receive(:make_update_processor).and_return(processor)
+
+            subject.start
+            expect(subject).to have_received(:make_update_processor).once
+
+            subject.start
+            subject.start
+            # Should still only be called once
+            expect(subject).to have_received(:make_update_processor).once
+          end
         end
 
         describe "#stop" do