Improve shutdown functionality to clear providers and reset state

Based on OpenFeature specification review, the shutdown method now:
- Calls shutdown on all registered providers
- Clears all providers from configuration
- Resets SDK to initial state for proper cleanup

Updated tests to verify providers are properly cleared after shutdown.
Updated documentation to reflect complete shutdown behavior.

Co-authored-by: josecolella <[email protected]>

Author: Copilot

README.md

@@ -223,7 +223,13 @@ end
 OpenFeature::SDK.shutdown
 ```
 
-When you call `OpenFeature::SDK.shutdown`, it will automatically call the `shutdown` method on all registered providers that support it. If a provider doesn't have a `shutdown` method, it will be safely ignored.
+When you call `OpenFeature::SDK.shutdown`, it will:
+
+1. Call the `shutdown` method on all registered providers that support it
+2. Clear all registered providers from the configuration 
+3. Reset the SDK to its initial state
+
+After shutdown, no providers will be available and the SDK will need to be reconfigured if you want to continue using it.
 
 To implement shutdown in your custom provider:
 

lib/open_feature/sdk/configuration.rb

@@ -37,12 +37,13 @@ def set_provider(provider, domain: nil)
         end
       end
 
-      # Shutdown all registered providers
+      # Shutdown all registered providers and clear the configuration
       def shutdown
         @provider_mutex.synchronize do
           @providers.each_value do |provider|
             provider.shutdown if provider.respond_to?(:shutdown)
           end
+          @providers.clear
         end
       end
     end

spec/open_feature/sdk/configuration_spec.rb

@@ -61,23 +61,30 @@
       let(:provider1) { OpenFeature::SDK::Provider::InMemoryProvider.new }
       let(:provider2) { OpenFeature::SDK::Provider::InMemoryProvider.new }
 
-      it "calls shutdown on all providers" do
+      it "calls shutdown on all providers and clears them" do
         configuration.set_provider(provider1)
         configuration.set_provider(provider2, domain: "testing")
 
         expect(provider1).to receive(:shutdown)
         expect(provider2).to receive(:shutdown)
 
         configuration.shutdown
+
+        # Verify providers are cleared
+        expect(configuration.provider).to be_nil
+        expect(configuration.provider(domain: "testing")).to be_nil
       end
     end
 
     context "when providers do not have shutdown methods" do
-      it "does not raise errors for providers without shutdown" do
+      it "does not raise errors for providers without shutdown and clears them" do
         provider_without_shutdown = OpenFeature::SDK::Provider::NoOpProvider.new
         configuration.set_provider(provider_without_shutdown)
 
         expect { configuration.shutdown }.not_to raise_error
+
+        # Verify providers are cleared
+        expect(configuration.provider).to be_nil
       end
     end
 

spec/specification/flag_evaluation_api_spec.rb

@@ -140,13 +140,20 @@
         expect(provider2).to receive(:shutdown)
 
         expect { OpenFeature::SDK.shutdown }.not_to raise_error
+
+        # Verify providers are cleared after shutdown
+        expect(OpenFeature::SDK.provider).to be_nil
+        expect(OpenFeature::SDK.provider(domain: "testing")).to be_nil
       end
 
       specify "Shutdown does not raise errors when providers don't have shutdown methods" do
         provider_without_shutdown = OpenFeature::SDK::Provider::NoOpProvider.new
         OpenFeature::SDK.set_provider(provider_without_shutdown)
 
         expect { OpenFeature::SDK.shutdown }.not_to raise_error
+
+        # Verify providers are cleared after shutdown
+        expect(OpenFeature::SDK.provider).to be_nil
       end
     end
   end