expose index array's loaded indexes

Author: morganchen12

FirebaseDatabaseUI/FUIIndexArray.h

@@ -118,6 +118,12 @@ didFailLoadWithError:(NSError *)error;
  */
 @property(nonatomic, copy, readonly) NSArray<FIRDataSnapshot *> *items;
 
+/**
+ * An immutable copy of the loaded indexes in the array. Returns an empty
+ * array if no indexes have loaded.
+ */
+@property(nonatomic, copy, readonly) NSArray<FIRDataSnapshot *> *indexes;
+
 /**
  * The delegate that this array should forward events to.
  */

FirebaseDatabaseUI/FUIIndexArray.m

@@ -74,7 +74,7 @@ - (void)observeQueries {
   [_indexArray observeQuery];
 }
 
-- (NSArray <FIRDataSnapshot *> *)items {
+- (NSArray<FIRDataSnapshot *> *)items {
   NSArray *observers = [self.observers copy];
   NSMutableArray *array = [[NSMutableArray alloc] initWithCapacity:observers.count];
   for (FUIQueryObserver *observer in observers) {
@@ -85,6 +85,10 @@ - (void)observeQueries {
   return [array copy];
 }
 
+- (NSArray<FIRDataSnapshot *> *) indexes {
+  return self.indexArray.items;
+}
+
 - (NSUInteger)count {
   return self.observers.count;
 }

FirebaseDatabaseUITests/FUIIndexArrayTest.m

@@ -74,15 +74,23 @@ - (void)tearDown {
 }
 
 - (void)testItHasContents {
+  NSArray *indexes = self.array.indexes;
   NSArray *items = self.array.items;
 
-  NSArray *expected = @[
+  NSArray *expectedIndexes = @[
+    [FUIFakeSnapshot snapWithKey:@"1" value:@(YES)],
+    [FUIFakeSnapshot snapWithKey:@"2" value:@(YES)],
+    [FUIFakeSnapshot snapWithKey:@"3" value:@(YES)],
+  ];
+
+  NSArray *expectedContents = @[
     [FUIFakeSnapshot snapWithKey:@"data" value:@"1"],
     [FUIFakeSnapshot snapWithKey:@"data" value:@"2"],
     [FUIFakeSnapshot snapWithKey:@"data" value:@"3"],
   ];
 
-  XCTAssertEqualObjects(items, expected, @"expected contents to equal %@", expected);
+  XCTAssertEqualObjects(indexes, expectedIndexes, @"expected indexes to equal %@", expectedIndexes);
+  XCTAssertEqualObjects(items, expectedContents, @"expected contents to equal %@", expectedContents);
 }
 
 - (void)testItUpdatesOnInsertion {