Add additional test to OptimizelyTest.java

Author: The-inside-man

core-api/src/main/java/com/optimizely/ab/Optimizely.java

@@ -1345,10 +1345,12 @@ private DecisionResponse<Map<String, Object>> getDecisionVariableMap(@Nonnull Fe
      */
     public Variation getFlagVariationByKey(String flagKey, String variationKey) {
         Map<String, List<Variation>> flagVariationsMap = getProjectConfig().getFlagVariationsMap();
-        List<Variation> variations = flagVariationsMap.get(flagKey);
-        for (Variation variation : variations) {
-            if (variation.getKey().equals(variationKey)) {
-                return variation;
+        if (flagVariationsMap.containsKey(flagKey)) {
+            List<Variation> variations = flagVariationsMap.get(flagKey);
+            for (Variation variation : variations) {
+                if (variation.getKey().equals(variationKey)) {
+                    return variation;
+                }
             }
         }
         return null;

core-api/src/test/java/com/optimizely/ab/OptimizelyTest.java

@@ -4655,4 +4655,15 @@ public void createUserContext_multiple() {
         assertTrue(user2.getAttributes().isEmpty());
     }
 
+    @Test
+    public void getFlagVariationByKey() throws IOException {
+        String flagKey = "double_single_variable_feature";
+        String variationKey = "pi_variation";
+        Optimizely optimizely = Optimizely.builder().withDatafile(validConfigJsonV4()).build();
+        Variation variation = optimizely.getFlagVariationByKey(flagKey, variationKey);
+
+        assertNotNull(variation);
+        assertEquals(variationKey, variation.getKey());
+    }
+
 }