fix: [go-feature-flag] Fix NullPointerException on checking anonymous user (#609)

Signed-off-by: itchyny <[email protected]>

Author: itchyny

providers/go-feature-flag/src/main/java/dev/openfeature/contrib/providers/gofeatureflag/bean/GoFeatureFlagUser.java

@@ -28,18 +28,25 @@ public class GoFeatureFlagUser {
      */
     public static GoFeatureFlagUser fromEvaluationContext(EvaluationContext ctx) {
         String key = ctx.getTargetingKey();
-        if (key == null || "".equals(key)) {
+        if (key == null || key.isEmpty()) {
             throw new TargetingKeyMissingError();
         }
-        Value anonymousValue = ctx.getValue(anonymousFieldName);
-        if (anonymousValue == null) {
-            anonymousValue = new Value(Boolean.FALSE);
-        }
-        boolean anonymous = anonymousValue.asBoolean();
+        boolean anonymous = isAnonymousUser(ctx);
         Map<String, Object> custom = new HashMap<>(ctx.asObjectMap());
         if (ctx.getValue(anonymousFieldName) != null) {
             custom.remove(anonymousFieldName);
         }
         return GoFeatureFlagUser.builder().anonymous(anonymous).key(key).custom(custom).build();
     }
+
+    /**
+     * isAnonymousUser is checking if the user in the evaluationContext is anonymous.
+     *
+     * @param ctx - EvaluationContext from open-feature
+     * @return true if the user is anonymous, false otherwise
+     */
+    public static boolean isAnonymousUser(EvaluationContext ctx) {
+        Value value = ctx.getValue(anonymousFieldName);
+        return value != null && value.asBoolean();
+    }
 }

providers/go-feature-flag/src/main/java/dev/openfeature/contrib/providers/gofeatureflag/hook/DataCollectorHook.java

@@ -2,6 +2,7 @@
 
 import com.fasterxml.jackson.core.JsonProcessingException;
 import dev.openfeature.contrib.providers.gofeatureflag.GoFeatureFlagProvider;
+import dev.openfeature.contrib.providers.gofeatureflag.bean.GoFeatureFlagUser;
 import dev.openfeature.contrib.providers.gofeatureflag.exception.InvalidOptions;
 import dev.openfeature.contrib.providers.gofeatureflag.hook.events.Event;
 import dev.openfeature.contrib.providers.gofeatureflag.hook.events.Events;
@@ -73,7 +74,7 @@ public void after(HookContext ctx, FlagEvaluationDetails details, Map hints) {
         Event event = Event.builder()
                 .key(ctx.getFlagKey())
                 .kind("feature")
-                .contextKind(ctx.getCtx().getValue("anonymous").asBoolean() ? "anonymousUser" : "user")
+                .contextKind(GoFeatureFlagUser.isAnonymousUser(ctx.getCtx()) ? "anonymousUser" : "user")
                 .defaultValue(false)
                 .variation(details.getVariant())
                 .value(details.getValue())
@@ -88,7 +89,7 @@ public void error(HookContext ctx, Exception error, Map hints) {
         Event event = Event.builder()
                 .key(ctx.getFlagKey())
                 .kind("feature")
-                .contextKind(ctx.getCtx().getValue("anonymous").asBoolean() ? "anonymousUser" : "user")
+                .contextKind(GoFeatureFlagUser.isAnonymousUser(ctx.getCtx()) ? "anonymousUser" : "user")
                 .creationDate(System.currentTimeMillis())
                 .defaultValue(true)
                 .variation("SdkDefault")

providers/go-feature-flag/src/test/java/dev/openfeature/contrib/providers/gofeatureflag/GoFeatureFlagProviderTest.java

@@ -750,6 +750,29 @@ void should_publish_events() {
         assertEquals(6, publishEventsRequestsReceived, "we have call 6 time more, so we should consider only those new calls");
     }
 
+    @SneakyThrows
+    @Test
+    void should_publish_events_context_without_anonymous() {
+        this.evaluationContext = new MutableContext("d45e303a-38c2-11ed-a261-0242ac120002");
+        GoFeatureFlagProvider g = new GoFeatureFlagProvider(GoFeatureFlagProviderOptions.builder()
+                .endpoint(this.baseUrl.toString())
+                .timeout(1000)
+                .enableCache(true)
+                .flushIntervalMs(50L)
+                .build());
+        String providerName = this.testName;
+        OpenFeatureAPI.getInstance().setProviderAndWait(providerName, g);
+        Client client = OpenFeatureAPI.getInstance().getClient(providerName);
+        client.getBooleanDetails("fail_500", false, this.evaluationContext);
+        Thread.sleep(100L);
+        assertEquals(1, publishEventsRequestsReceived, "We should have 1 event waiting to be publish");
+        client.getBooleanDetails("bool_targeting_match", false, this.evaluationContext);
+        client.getBooleanDetails("bool_targeting_match", false, this.evaluationContext);
+        client.getBooleanDetails("bool_targeting_match", false, this.evaluationContext);
+        Thread.sleep(100);
+        assertEquals(3, publishEventsRequestsReceived, "We pass the flush interval, we should have 3 events");
+    }
+
     private String readMockResponse(String filename) throws Exception {
         URL url = getClass().getClassLoader().getResource("mock_responses/" + filename);
         assert url != null;