Ignore containers when checking compared fields existence in the recu…

…rsive comparison

Fix #3349

Containers support is addressed by #3354

assertj-core/src/main/java/org/assertj/core/api/recursive/comparison/DualValue.java

@@ -16,6 +16,7 @@
 import static java.lang.System.identityHashCode;
 import static java.util.Collections.unmodifiableList;
 import static java.util.Objects.requireNonNull;
+import static org.assertj.core.internal.RecursiveHelper.isContainer;
 import static org.assertj.core.api.recursive.comparison.FieldLocation.rootFieldLocation;
 import static org.assertj.core.util.Arrays.array;
 import static org.assertj.core.util.Arrays.isArray;
@@ -327,20 +328,6 @@ public boolean hasNoNullValues() {
     return actual != null && expected != null;
   }
 
-  private static boolean isContainer(Object o) {
-    return o instanceof Iterable ||
-           o instanceof Map ||
-           o instanceof Optional ||
-           o instanceof AtomicReference ||
-           o instanceof AtomicReferenceArray ||
-           o instanceof AtomicBoolean ||
-           o instanceof AtomicInteger ||
-           o instanceof AtomicIntegerArray ||
-           o instanceof AtomicLong ||
-           o instanceof AtomicLongArray ||
-           isArray(o);
-  }
-
   public boolean hasPotentialCyclingValues() {
     return isPotentialCyclingValue(actual) && isPotentialCyclingValue(expected);
   }

assertj-core/src/main/java/org/assertj/core/api/recursive/comparison/RecursiveComparisonConfiguration.java

@@ -20,6 +20,7 @@
 import static java.util.stream.Collectors.toSet;
 import static org.assertj.core.configuration.ConfigurationProvider.CONFIGURATION_PROVIDER;
 import static org.assertj.core.data.MapEntry.entry;
+import static org.assertj.core.internal.RecursiveHelper.isContainer;
 import static org.assertj.core.internal.TypeComparators.defaultTypeComparators;
 import static org.assertj.core.util.Lists.list;
 import static org.assertj.core.util.Sets.newLinkedHashSet;
@@ -1095,17 +1096,23 @@ void checkComparedFieldsExist(Object actual) {
 
   private Optional<Entry<FieldLocation, String>> checkComparedFieldExists(Object actual, FieldLocation comparedFieldLocation) {
     Object node = actual;
-    for (int nestingLevel = 0; nestingLevel < comparedFieldLocation.getDecomposedPath().size(); nestingLevel++) {
+    int nestingLevel = 0;
+    while (nestingLevel < comparedFieldLocation.getDecomposedPath().size()) {
       if (node == null) {
         // won't be able to get children nodes, assume the field is known as we can't check it
         return Optional.empty();
       }
+      if (isContainer(node)) {
+        // TODO: supported with https://github.com/assertj/assertj/issues/3354
+        return Optional.empty();
+      }
       String comparedFieldNodeNameElement = comparedFieldLocation.getDecomposedPath().get(nestingLevel);
       Set<String> nodeNames = introspectionStrategy.getChildrenNodeNamesOf(node);
       if (!nodeNames.contains(comparedFieldNodeNameElement)) {
         return Optional.of(entry(comparedFieldLocation, comparedFieldNodeNameElement));
       }
       node = introspectionStrategy.getChildNodeValue(comparedFieldNodeNameElement, node);
+      nestingLevel++;
     }
     return Optional.empty();
   }

assertj-core/src/main/java/org/assertj/core/internal/RecursiveHelper.java

@@ -0,0 +1,29 @@
+package org.assertj.core.internal;
+
+import java.util.Map;
+import java.util.Optional;
+import java.util.concurrent.atomic.AtomicBoolean;
+import java.util.concurrent.atomic.AtomicInteger;
+import java.util.concurrent.atomic.AtomicIntegerArray;
+import java.util.concurrent.atomic.AtomicLong;
+import java.util.concurrent.atomic.AtomicLongArray;
+import java.util.concurrent.atomic.AtomicReference;
+import java.util.concurrent.atomic.AtomicReferenceArray;
+
+import static org.assertj.core.util.Arrays.isArray;
+
+public class RecursiveHelper {
+  public static boolean isContainer(Object o) {
+    return o instanceof Iterable ||
+           o instanceof Map ||
+           o instanceof Optional ||
+           o instanceof AtomicReference ||
+           o instanceof AtomicReferenceArray ||
+           o instanceof AtomicBoolean ||
+           o instanceof AtomicInteger ||
+           o instanceof AtomicIntegerArray ||
+           o instanceof AtomicLong ||
+           o instanceof AtomicLongArray ||
+           isArray(o);
+  }
+}

assertj-core/src/test/java/org/assertj/core/api/recursive/comparison/RecursiveComparisonAssert_isEqualTo_comparingOnlyFields_Test.java

@@ -300,7 +300,6 @@ private static Stream<Arguments> should_fail_when_non_existent_fields_specified(
     Person alice = new Person("Alice");
     Person jack = new Person("Jack");
     Person joan = new Person("Joan");
-    Person joe = new Person("Joe");
     john.neighbour = jack;
     alice.neighbour = joan;
     jack.neighbour = john;
@@ -318,8 +317,8 @@ private static Stream<Arguments> should_fail_when_non_existent_fields_specified(
                      arguments(john, alice, array("name", "neighbour", "number"), "{number}"),
                      arguments(john, alice, array("neighbor"), "{neighbor}"),
                      arguments(john, alice, array("neighbour.neighbor.name"), "{neighbor in <neighbour.neighbor.name>}"),
-                     arguments(sherlockHolmes, drWatson, array("friends.other"), "{other in <friends.other>}"),
-                     arguments(sherlockHolmes, drWatson, array("friends.name"), "{name in <friends.name>}"),
+                     // TODO for https://github.com/assertj/assertj/issues/3354
+                     // arguments(sherlockHolmes, drWatson, array("friends.other"), "{other in <friends.other>}"),
                      arguments(john, alice, array("neighbour.neighbour.name", "neighbour.neighbour.number"),
                                "{number in <neighbour.neighbour.number>}"));
   }
@@ -426,15 +425,15 @@ void should_only_check_compared_fields_existence_at_the_root_level() {
                 .isEqualTo(expected);
   }
 
-  class WithNames {
+  static class WithNames {
     Collection<Name> names;
 
     public WithNames(Collection<Name> names) {
       this.names = names;
     }
   }
 
-  class Name {
+  static class Name {
     String first;
     String last;
 
@@ -444,4 +443,17 @@ public Name(String first, String last) {
     }
   }
 
+  // https://github.com/assertj/assertj/issues/3354
+  @Test
+  void checking_compared_fields_existence_should_skip_containers_in_field_location() {
+    // GIVEN
+    FriendlyPerson sherlock1 = new FriendlyPerson("Sherlock Holmes");
+    sherlock1.friends.add(new FriendlyPerson("Dr. John Watson"));
+    FriendlyPerson sherlock2 = new FriendlyPerson("Sherlock Holmes");
+    sherlock2.friends.add(new FriendlyPerson("Dr. John Watson"));
+    // WHEN/THEN
+    then(sherlock1).usingRecursiveComparison()
+                   .comparingOnlyFields("friends.name")
+                   .isEqualTo(sherlock2);
+  }
 }