[android][database] Fix hanging db when querying object with large numerical keys

android/src/main/java/io/invertase/firebase/Utils.java

@@ -213,16 +213,22 @@ public class Utils {
   }
 
   /**
+   * Data should be treated as an array if:
+   * 1) All the keys are integers
+   * 2) More than half the keys between 0 and the maximum key in the object have non-empty values
+   *
+   * Definition from: https://firebase.googleblog.com/2014/04/best-practices-arrays-in-firebase.html
    *
    * @param snapshot
    * @return
    */
   private static boolean isArray(DataSnapshot snapshot) {
     long expectedKey = -1;
+    long maxAllowedKey = (snapshot.getChildrenCount() * 2) - 1;
     for (DataSnapshot child : snapshot.getChildren()) {
       try {
         long key = Long.parseLong(child.getKey());
-        if (key > expectedKey) {
+        if (key > expectedKey && key <= maxAllowedKey) {
           expectedKey = key;
         } else {
           return false;
@@ -235,16 +241,22 @@ public class Utils {
   }
 
   /**
+   * Data should be treated as an array if:
+   * 1) All the keys are integers
+   * 2) More than half the keys between 0 and the maximum key in the object have non-empty values
+   *
+   * Definition from: https://firebase.googleblog.com/2014/04/best-practices-arrays-in-firebase.html
    *
    * @param mutableData
    * @return
    */
   private static boolean isArray(MutableData mutableData) {
     long expectedKey = -1;
+    long maxAllowedKey = (mutableData.getChildrenCount() * 2) - 1;
     for (MutableData child : mutableData.getChildren()) {
       try {
         long key = Long.parseLong(child.getKey());
-        if (key > expectedKey) {
+        if (key > expectedKey && key <= maxAllowedKey) {
           expectedKey++;
         } else {
           return false;

tests/src/tests/database/ref/issueSpecificTests.js

@@ -1,7 +1,7 @@
 import should from 'should';
 import DatabaseContents from '../../support/DatabaseContents';
 
-function issueTests({ fdescribe, describe, it, context, firebase }) {
+function issueTests({ describe, it, context, firebase }) {
   describe('issue_100', () => {
     context('array-like values should', () => {
       it('return null in returned array at positions where a key is missing', async () => {
@@ -12,9 +12,6 @@ function issueTests({ fdescribe, describe, it, context, firebase }) {
         // Test
 
         return ref.once('value').then((snapshot) => {
-          // Assertion
-          // console.warn(JSON.stringify(snapshot.val()));
-
           snapshot.val().should.eql([null, DatabaseContents.ISSUES[100][1], DatabaseContents.ISSUES[100][2], DatabaseContents.ISSUES[100][3]]);
         });
       });
@@ -69,6 +66,22 @@ function issueTests({ fdescribe, describe, it, context, firebase }) {
       });
     });
   });
+
+  describe('issue_171', () => {
+    context('non array-like values should', () => {
+      it('return as objects', async () => {
+        // Setup
+
+        const ref = firebase.native.database().ref('tests/issues/171');
+
+        // Test
+
+        return ref.once('value').then((snapshot) => {
+          snapshot.val().should.eql(DatabaseContents.ISSUES[171]);
+        });
+      });
+    });
+  });
 }
 
 export default issueTests;

tests/src/tests/support/DatabaseContents.js

@@ -63,5 +63,33 @@ export default {
         latitude: 37,
       },
     },
+
+    // https://github.com/invertase/react-native-firebase/issues/171
+    171: {
+      10053768200609241: {
+        email: 'emaila@hotmail.com',
+        name: 'Sek Ranger',
+        profile_picture: 'https://url.to/picture',
+        uid: 'n6V8vACidyW4OKxnELkBbW83JaS2',
+      },
+      10053925505239749: {
+        email: 'emailb@hotmail.com',
+        name: 'Gu Hungry',
+        profile_picture: 'https://url.to/picture',
+        uid: 'Qq4Pwm7H2kO6sJIMLAJxuhAGGh22',
+      },
+      10106631429240929: {
+        email: 'emailc@gmail.com',
+        name: 'Chwang',
+        profile_picture: 'https://url.to/picture',
+        uid: 'T7VVrveS0dPs3idmgetLUfQsLZs1',
+      },
+      10106631429240930: {
+        email: 'emaild@gmail.com',
+        name: 'Introv Bigs',
+        profile_picture: 'https://url.to/picture',
+        uid: 'aNYxLexOb2WsXGOPiEAu47q5bxH3',
+      },
+    },
   },
 };