feat: Support provider initialization and shutdown

lib/ldclient-openfeature/provider.rb

@@ -39,6 +39,31 @@ def initialize(sdk_key, config = LaunchDarkly::Config.default, wait_for_seconds
         @metadata = ::OpenFeature::SDK::Provider::ProviderMetadata.new(name: "launchdarkly-openfeature-server").freeze
       end
 
+      #
+      # Called by the OpenFeature SDK when this provider is set. The LaunchDarkly client has already been given the
+      # opportunity to initialize, so this only reports whether that succeeded.
+      #
+      # @param _evaluation_context [::OpenFeature::SDK::EvaluationContext, nil]
+      #
+      # @return [void]
+      #
+      def init(_evaluation_context = nil)
+        return if @client.initialized?
+
+        state = @client.data_source_status_provider.status.state
+        raise "the LaunchDarkly client was unable to initialize; the data source state is #{state}"
+      end
+
+      #
+      # Called by the OpenFeature SDK when this provider is replaced or the SDK is shut down. The LaunchDarkly client
+      # cannot be restarted, so a new provider instance is required afterward.
+      #
+      # @return [void]
+      #
+      def shutdown
+        @client.close
+      end
+
       def fetch_boolean_value(flag_key:, default_value:, evaluation_context: nil)
         resolve_value(:boolean, flag_key, default_value, evaluation_context)
       end

spec/provider_spec.rb

@@ -18,6 +18,26 @@
     expect(provider.client).to be_a LaunchDarkly::LDClient
   end
 
+  it "init succeeds when the client is initialized" do
+    expect { provider.init(evaluation_context) }.not_to raise_error
+  end
+
+  it "init raises when the client failed to initialize" do
+    status = LaunchDarkly::Interfaces::DataSource::Status.new(LaunchDarkly::Interfaces::DataSource::Status::OFF, Time.now, nil)
+    status_provider = double(status: status)
+    allow(provider.client).to receive_messages(initialized?: false, data_source_status_provider: status_provider)
+
+    expect { provider.init(evaluation_context) }.to raise_error(/unable to initialize/)
+  end
+
+  it "shutdown closes the client" do
+    allow(provider.client).to receive(:close)
+
+    provider.shutdown
+
+    expect(provider.client).to have_received(:close)
+  end
+
   it "not providing context returns error" do
     resolution_details = provider.fetch_boolean_value(flag_key: "flag-key", default_value: true)