feat: Add support for fallback-action

src/main/java/no/finn/unleash/DefaultUnleash.java

@@ -1,11 +1,5 @@
 package no.finn.unleash;
 
-import java.util.Arrays;
-import java.util.HashMap;
-import java.util.List;
-import java.util.Map;
-import java.util.Optional;
-
 import no.finn.unleash.event.EventDispatcher;
 import no.finn.unleash.event.ToggleEvaluated;
 import no.finn.unleash.metric.UnleashMetricService;
@@ -17,6 +11,8 @@
 import no.finn.unleash.strategy.*;
 import no.finn.unleash.util.UnleashConfig;
 
+import java.util.*;
+
 import static java.util.Optional.ofNullable;
 import static no.finn.unleash.Variant.DISABLED_VARIANT;
 import static no.finn.unleash.variant.VariantUtil.selectVariant;
@@ -63,6 +59,14 @@ public DefaultUnleash(UnleashConfig unleashConfig, ToggleRepository toggleReposi
         metricService.register(strategyMap.keySet());
     }
 
+    private static FeatureToggleRepository defaultToggleRepository(UnleashConfig unleashConfig) {
+        return new FeatureToggleRepository(
+                unleashConfig,
+                new HttpToggleFetcher(unleashConfig),
+                new ToggleBackupHandlerFile(unleashConfig)
+        );
+    }
+
     @Override
     public boolean isEnabled(final String toggleName) {
         return isEnabled(toggleName, false);
@@ -73,12 +77,33 @@ public boolean isEnabled(final String toggleName, final boolean defaultSetting)
         return isEnabled(toggleName, contextProvider.getContext(), defaultSetting);
     }
 
+    public boolean isEnabled(final String toggleName, final FallbackAction fallbackAction) {
+        FeatureToggle featureToggle = toggleRepository.getToggle(toggleName);
+        boolean enabled = isEnabled(featureToggle, contextProvider.getContext(), false);
+
+        if(!enabled && fallbackAction != null) {
+            fallbackAction.apply(toggleName, contextProvider.getContext());
+        }
+
+        return enabled;
+    }
+
+    public boolean isEnabled(final String toggleName, boolean defaultSetting, final FallbackAction fallbackAction) {
+        FeatureToggle featureToggle = toggleRepository.getToggle(toggleName);
+
+        if(featureToggle == null && fallbackAction != null) {
+            fallbackAction.apply(toggleName, contextProvider.getContext());
+        }
+
+        return isEnabled(featureToggle, contextProvider.getContext(), defaultSetting);
+    }
+
     @Override
-    public boolean isEnabled(final String toggleName, final UnleashContext context ,final boolean defaultSetting) {
+    public boolean isEnabled(final String toggleName, final UnleashContext context, final boolean defaultSetting) {
         FeatureToggle featureToggle = toggleRepository.getToggle(toggleName);
         boolean enabled = isEnabled(featureToggle, context, defaultSetting);
         count(toggleName, enabled);
-        eventDispatcher.dispatch(new ToggleEvaluated(toggleName,enabled));
+        eventDispatcher.dispatch(new ToggleEvaluated(toggleName, enabled));
         return enabled;
     }
 

src/main/java/no/finn/unleash/FakeUnleash.java

@@ -27,6 +27,35 @@ public boolean isEnabled(String toggleName, boolean defaultSetting) {
         }
     }
 
+    @Override
+    public boolean isEnabled(String toggleName, boolean defaultSetting, FallbackAction fallbackAction) {
+        if(enableAll) {
+            return true;
+        } else if(disableAll) {
+
+            return false;
+        } else {
+            if(!features.containsKey(toggleName)) {
+                fallbackAction.apply(toggleName, UnleashContext.builder().build());
+            }
+            return features.getOrDefault(toggleName, defaultSetting);
+        }
+    }
+
+    @Override
+    public boolean isEnabled(String toggleName, FallbackAction fallbackAction) {
+        if(enableAll) {
+            return true;
+        } else if(disableAll) {
+            return false;
+        } else {
+            if(!features.containsKey(toggleName)) {
+                fallbackAction.apply(toggleName, UnleashContext.builder().build());
+            }
+            return features.getOrDefault(toggleName, false);
+        }
+    }
+
     @Override
     public Variant getVariant(String toggleName, UnleashContext context) {
         return getVariant(toggleName, Variant.DISABLED_VARIANT);

src/main/java/no/finn/unleash/FallbackAction.java

@@ -0,0 +1,5 @@
+package no.finn.unleash;
+
+public interface FallbackAction {
+    void apply(String toggleName, UnleashContext unleashContext);
+}

src/main/java/no/finn/unleash/Unleash.java

@@ -15,6 +15,10 @@ default boolean isEnabled(String toggleName, UnleashContext context, boolean def
         return isEnabled(toggleName, defaultSetting);
     }
 
+    boolean isEnabled(final String toggleName, boolean defaultSetting, final FallbackAction fallbackAction);
+
+    boolean isEnabled(final String toggleName, final FallbackAction fallbackAction);
+
     Variant getVariant(final String toggleName, final UnleashContext context);
 
     Variant getVariant(final String toggleName, final UnleashContext context, final Variant defaultValue);