closes #201: $and can have more than 2 operands

Author: William Delanoue

src/main/java/com/github/fakemongo/impl/ExpressionParser.java

@@ -27,9 +27,7 @@
 import java.util.Set;
 import java.util.UUID;
 import java.util.regex.Pattern;
-import org.bson.BSON;
 import org.bson.LazyBSONList;
-import org.bson.codecs.Encoder;
 import org.bson.types.Binary;
 import org.bson.types.MaxKey;
 import org.bson.types.MinKey;
@@ -371,7 +369,7 @@ public boolean apply(Object object) {
 
   private ValueFilter buildValueFilter(final Object object) {
     if (isDbObject(object)) {
-        return buildValueFilter(buildFilter(toDbObject(object)));
+      return buildValueFilter(buildFilter(toDbObject(object)));
     }
     if (object instanceof Pattern) {
       return buildValueFilter((Pattern) object);
@@ -615,9 +613,10 @@ private Filter buildExpressionFilter(final List<String> path, Object expression)
         if (matchCount == 0) {
           return simpleFilter(path, expression);
         }
-        if (matchCount > 2) {
-          throw new FongoException("Invalid expression for key " + path + ": " + expression);
-        }
+        // WDEL : remove when trying to correct #201
+//        if (matchCount > 2) {
+//          throw new FongoException("Invalid expression for key " + path + ": " + expression);
+//        }
         return andFilter;
       }
     } else if (expression instanceof Pattern) {

src/test/java/com/github/fakemongo/FongoTest.java

@@ -3406,6 +3406,37 @@ public void should_fully_rename_a_collection() {
     assertThat(dbObjects).containsExactly(new BasicDBObject("_id", 1).append("tags", new BasicDBList()));
   }
 
+  @Test
+  public void should_$ne_on_empty_array_works() {
+    // Given
+    DBCollection collection = fongoRule.newCollection("db");
+    collection.insert(new BasicDBObject("_id", 1).append("tags", new BasicDBList()));
+    collection.insert(new BasicDBObject("_id", 2).append("tags", Util.list("Hi")));
+
+    // When
+    final List<DBObject> dbObjects = collection.find(new BasicDBObject("tags", new BasicDBObject("$ne", new BasicDBList()))).toArray();
+
+    // Then
+    assertThat(dbObjects).containsExactly(new BasicDBObject("_id", 2).append("tags", Util.list("Hi")));
+  }
+
+  // https://github.com/fakemongo/fongo/issues/201
+  @Test
+  public void should_$and_have_more_than_2_operands() {
+    // Given
+    DBCollection collection = fongoRule.newCollection("db");
+    collection.insert(new BasicDBObject("_id", 1).append("tags", new BasicDBList()));
+    collection.insert(new BasicDBObject("_id", 2).append("tags", Util.list("2")));
+    collection.insert(new BasicDBObject("_id", 3).append("tags", Util.list("4")));
+    collection.insert(new BasicDBObject("_id", 5).append("ntags", Util.list("4")));
+
+    // When
+    final List<DBObject> dbObjects = collection.find(new BasicDBObject("tags", new BasicDBObject("$exists", true).append("$ne", new BasicDBList()).append("$nin", Util.list("1", "2")))).toArray();
+
+    // Then
+    assertThat(dbObjects).containsExactly(new BasicDBObject("_id", 3).append("tags", Util.list("4")));
+  }
+
   @Test
   public void should_ping_fongo() {
     // Given