Special case the null client name

Author: justinabrahms

src/main/java/dev/openfeature/sdk/OpenFeatureAPI.java

@@ -84,7 +84,11 @@ public EvaluationContext getEvaluationContext() {
      * {@inheritDoc}
      */
     public void setProvider(FeatureProvider provider) {
-        setProvider(DEFAULT_PROVIDER_KEY, provider);
+        if (provider == null) {
+            this.providers.remove(DEFAULT_PROVIDER_KEY);
+        } else {
+            setProvider(DEFAULT_PROVIDER_KEY, provider);
+        }
     }
 
     /**
@@ -112,9 +116,11 @@ public FeatureProvider getProvider() {
      */
     public FeatureProvider getProviderForClientOrDefault(String name) {
         try (AutoCloseableLock __ = providerLock.writeLockAutoCloseable()) {
-            FeatureProvider val = this.providers.get(name);
-            if (val != null) {
-                return val;
+            if (name != null) { // this happens when a client name isn't set.
+                FeatureProvider val = this.providers.get(name);
+                if (val != null) {
+                    return val;
+                }
             }
             return this.providers.get(DEFAULT_PROVIDER_KEY);
         }

src/test/java/dev/openfeature/sdk/OpenFeatureClientTest.java

@@ -27,7 +27,7 @@ class OpenFeatureClientTest implements HookFixtures {
     @DisplayName("should not throw exception if hook has different type argument than hookContext")
     void shouldNotThrowExceptionIfHookHasDifferentTypeArgumentThanHookContext() {
         OpenFeatureAPI api = mock(OpenFeatureAPI.class);
-        when(api.getProvider()).thenReturn(new DoSomethingProvider());
+        when(api.getProviderForClientOrDefault(any())).thenReturn(new DoSomethingProvider());
         when(api.getHooks()).thenReturn(Arrays.asList(mockBooleanHook(), mockStringHook()));
 
         OpenFeatureClient client = new OpenFeatureClient(api, "name", "version");
@@ -57,6 +57,8 @@ void mergeContextTest() {
             context -> context.getTargetingKey().equals(targetingKey)))).thenReturn(ProviderEvaluation.<Boolean>builder()
           .value(true).build());
         when(api.getProvider()).thenReturn(mockProvider);
+        when(api.getProviderForClientOrDefault(any())).thenReturn(mockProvider);
+
 
         OpenFeatureClient client = new OpenFeatureClient(api, "name", "version");
         client.setEvaluationContext(ctx);