v2 Java changes for consistency with other SDKs

src/main/java/com/launchdarkly/client/EvaluationException.java

@@ -0,0 +1,10 @@
+package com.launchdarkly.client;
+
+/**
+ * An error indicating an abnormal result from evaluating a feature
+ */
+class EvaluationException extends Exception {
+  public EvaluationException(String message) {
+    super(message);
+  }
+}

src/main/java/com/launchdarkly/client/FeatureFlag.java

@@ -50,44 +50,33 @@ static Map<String, FeatureFlag> fromJsonMap(String json) {
     this.deleted = deleted;
   }
 
-  Integer getOffVariation() {
-    return this.offVariation;
-  }
-
-  JsonElement getOffVariationValue() {
-    if (offVariation != null && offVariation < variations.size()) {
-      return variations.get(offVariation);
-    }
-    return null;
-  }
-
-  EvalResult evaluate(LDUser user, FeatureStore featureStore) {
+  EvalResult evaluate(LDUser user, FeatureStore featureStore) throws EvaluationException {
     if (user == null || user.getKey() == null) {
-      return null;
+      throw new EvaluationException("User or user key is null");
     }
     List<FeatureRequestEvent> prereqEvents = new ArrayList<>();
-    Set<String> visited = new HashSet<>();
-    JsonElement value = evaluate(user, featureStore, prereqEvents, visited);
+    JsonElement value = evaluate(user, featureStore, prereqEvents);
     return new EvalResult(value, prereqEvents);
   }
 
   // Returning either a JsonElement or null indicating prereq failure/error.
-  private JsonElement evaluate(LDUser user, FeatureStore featureStore, List<FeatureRequestEvent> events, Set<String> visited) {
+  private JsonElement evaluate(LDUser user, FeatureStore featureStore, List<FeatureRequestEvent> events) throws EvaluationException {
     boolean prereqOk = true;
-    visited.add(key);
     for (Prerequisite prereq : prerequisites) {
-      if (visited.contains(prereq.getKey())) {
-        logger.error("Prerequisite cycle detected when evaluating feature flag: " + key);
-        return null;
-      }
       FeatureFlag prereqFeatureFlag = featureStore.get(prereq.getKey());
       JsonElement prereqEvalResult = null;
       if (prereqFeatureFlag == null) {
         logger.error("Could not retrieve prerequisite flag: " + prereq.getKey() + " when evaluating: " + key);
         return null;
       } else if (prereqFeatureFlag.isOn()) {
-        prereqEvalResult = prereqFeatureFlag.evaluate(user, featureStore, events, visited);
-        if (prereqEvalResult == null || !prereqEvalResult.equals(prereqFeatureFlag.getVariation(prereq.getVariation()))) {
+        prereqEvalResult = prereqFeatureFlag.evaluate(user, featureStore, events);
+        try {
+          JsonElement variation = prereqFeatureFlag.getVariation(prereq.getVariation());
+          if (prereqEvalResult == null || variation == null || !prereqEvalResult.equals(variation)) {
+            prereqOk = false;
+          }
+        } catch (EvaluationException err) {
+          logger.warn("Error evaluating prerequisites: " + err.getMessage());
           prereqOk = false;
         }
       } else {
@@ -123,10 +112,30 @@ private Integer evaluateIndex(LDUser user) {
     return fallthrough.variationIndexForUser(user, key, salt);
   }
 
-  private JsonElement getVariation(Integer index) {
-    if (index == null || index >= variations.size()) {
+  JsonElement getOffVariationValue() throws EvaluationException {
+    if (offVariation == null) {
       return null;
-    } else {
+    }
+
+    if (offVariation >= variations.size()) {
+      throw new EvaluationException("Invalid off variation index");
+    }
+
+    return variations.get(offVariation);
+  }
+
+  private JsonElement getVariation(Integer index) throws EvaluationException {
+    // If the supplied index is null, then rules didn't match, and we want to return
+    // the off variation
+    if (index == null) {
+      return null;
+    }
+    // If the index doesn't refer to a valid variation, that's an unexpected exception and we will
+    // return the default variation
+    else if (index >= variations.size()) {
+      throw new EvaluationException("Invalid index");
+    }
+    else {
       return variations.get(index);
     }
   }
@@ -171,6 +180,8 @@ List<JsonElement> getVariations() {
     return variations;
   }
 
+  Integer getOffVariation() { return offVariation; }
+
   static class EvalResult {
     private final JsonElement value;
     private final List<FeatureRequestEvent> prerequisiteEvents;

src/main/java/com/launchdarkly/client/LDClient.java

@@ -294,47 +294,36 @@ public JsonElement jsonVariation(String featureKey, LDUser user, JsonElement def
     return value;
   }
 
-
   private JsonElement evaluate(String featureKey, LDUser user, JsonElement defaultValue) {
     if (!initialized()) {
       return defaultValue;
     }
     try {
       FeatureFlag featureFlag = config.featureStore.get(featureKey);
-      if (featureFlag != null) {
-        if (config.stream && config.debugStreaming) {
-          FeatureFlag pollingResult = requestor.makeRequest(featureKey, true);
-          if (!featureFlag.equals(pollingResult)) {
-            logger.warn("Mismatch between streaming and polling feature! Streaming: {} Polling: {}", featureFlag, pollingResult);
-          }
-        }
-      } else {
+      if (featureFlag == null) {
         logger.warn("Unknown feature flag " + featureKey + "; returning default value: ");
         return defaultValue;
       }
       if (featureFlag.isOn()) {
         FeatureFlag.EvalResult evalResult = featureFlag.evaluate(user, config.featureStore);
-        if (evalResult != null) {
           if (!isOffline()) {
             for (FeatureRequestEvent event : evalResult.getPrerequisiteEvents()) {
               eventProcessor.sendEvent(event);
             }
           }
-          if (evalResult.getValue() == null) {
-            return defaultValue;
-          } else {
+          if (evalResult.getValue() != null) {
             return evalResult.getValue();
           }
-        }
-      } else {
-        JsonElement offVariation = featureFlag.getOffVariationValue();
-        if (offVariation != null) {
-          return offVariation;
-        }
+      }
+      JsonElement offVariation = featureFlag.getOffVariationValue();
+      if (offVariation != null) {
+        return offVariation;
       }
     } catch (Exception e) {
       logger.error("Encountered exception in LaunchDarkly client", e);
     }
+
+
     return defaultValue;
   }
 

src/main/java/com/launchdarkly/client/LDConfig.java

@@ -37,7 +37,6 @@ public final class LDConfig {
   final int flushInterval;
   final HttpHost proxyHost;
   final boolean stream;
-  final boolean debugStreaming;
   final FeatureStore featureStore;
   final boolean useLdd;
   final boolean offline;
@@ -55,7 +54,6 @@ protected LDConfig(Builder builder) {
     this.proxyHost = builder.proxyHost();
     this.streamURI = builder.streamURI;
     this.stream = builder.stream;
-    this.debugStreaming = builder.debugStreaming;
     this.featureStore = builder.featureStore;
     this.useLdd = builder.useLdd;
     this.offline = builder.offline;
@@ -91,7 +89,6 @@ public static class Builder {
     private int proxyPort = -1;
     private String proxyScheme;
     private boolean stream = true;
-    private boolean debugStreaming = false;
     private boolean useLdd = false;
     private boolean offline = false;
     private long pollingIntervalMillis = DEFAULT_POLLING_INTERVAL_MILLIS;
@@ -140,18 +137,6 @@ public Builder featureStore(FeatureStore store) {
       return this;
     }
 
-    /**
-     * Set whether we should debug streaming mode. If set, the client will fetch features via polling and compare the
-     * retrieved feature with the value in the feature store. There is a performance cost to this, so it is not
-     * recommended for production use.
-     * @param debugStreaming whether streaming mode should be debugged
-     * @return the builder
-     */
-    public Builder debugStreaming(boolean debugStreaming) {
-      this.debugStreaming = debugStreaming;
-      return this;
-    }
-
     /**
      * Set whether streaming mode should be enabled. By default, streaming is enabled.
      * @param stream whether streaming mode should be enabled

src/main/java/com/launchdarkly/client/Operator.java

@@ -25,13 +25,6 @@ public boolean apply(JsonPrimitive uValue, JsonPrimitive cValue) {
       if (uValue.isNumber() && cValue.isNumber()) {
         return uValue.getAsDouble() == cValue.getAsDouble();
       }
-      DateTime uDateTime = Util.jsonPrimitiveToDateTime(uValue);
-      if (uDateTime != null) {
-        DateTime cDateTime = Util.jsonPrimitiveToDateTime(cValue);
-        if (cDateTime != null) {
-          return uDateTime.getMillis() == cDateTime.getMillis();
-        }
-      }
       return false;
     }
   },

src/test/java/com/launchdarkly/client/FeatureFlagTest.java

@@ -21,54 +21,7 @@ public void before() {
   }
 
   @Test
-  public void testPrereqSelfCycle() {
-    String keyA = "keyA";
-    FeatureFlag f = newFlagWithPrereq(keyA, keyA);
-
-    featureStore.upsert(keyA, f);
-    LDUser user = new LDUser.Builder("userKey").build();
-
-    FeatureFlag.EvalResult actual = f.evaluate(user, featureStore);
-
-    Assert.assertNull(actual.getValue());
-    Assert.assertNotNull(actual.getPrerequisiteEvents());
-    Assert.assertEquals(0, actual.getPrerequisiteEvents().size());
-  }
-
-  @Test
-  public void testPrereqSimpleCycle() {
-    String keyA = "keyA";
-    String keyB = "keyB";
-    FeatureFlag f1 = newFlagWithPrereq(keyA, keyB);
-    FeatureFlag f2 = newFlagWithPrereq(keyB, keyA);
-
-    featureStore.upsert(f1.getKey(), f1);
-    featureStore.upsert(f2.getKey(), f2);
-    LDUser user = new LDUser.Builder("userKey").build();
-    Assert.assertNull(f1.evaluate(user, featureStore).getValue());
-    Assert.assertNull(f2.evaluate(user, featureStore).getValue());
-  }
-
-  @Test
-  public void testPrereqCycle() {
-    String keyA = "keyA";
-    String keyB = "keyB";
-    String keyC = "keyC";
-    FeatureFlag f1 = newFlagWithPrereq(keyA, keyB);
-    FeatureFlag f2 = newFlagWithPrereq(keyB, keyC);
-    FeatureFlag f3 = newFlagWithPrereq(keyC, keyA);
-
-    featureStore.upsert(f1.getKey(), f1);
-    featureStore.upsert(f2.getKey(), f2);
-    featureStore.upsert(f3.getKey(), f3);
-    LDUser user = new LDUser.Builder("userKey").build();
-    Assert.assertNull(f1.evaluate(user, featureStore).getValue());
-    Assert.assertNull(f2.evaluate(user, featureStore).getValue());
-    Assert.assertNull(f3.evaluate(user, featureStore).getValue());
-  }
-
-  @Test
-  public void testPrereqDoesNotExist() {
+  public void testPrereqDoesNotExist() throws EvaluationException {
     String keyA = "keyA";
     String keyB = "keyB";
     FeatureFlag f1 = newFlagWithPrereq(keyA, keyB);
@@ -83,7 +36,7 @@ public void testPrereqDoesNotExist() {
   }
 
   @Test
-  public void testPrereqCollectsEventsForPrereqs() {
+  public void testPrereqCollectsEventsForPrereqs() throws EvaluationException {
     String keyA = "keyA";
     String keyB = "keyB";
     String keyC = "keyC";