fix(database, other): correctly reject for unsupported keepSynced API

previously it was attempting to reject but using an undefined helper
function to do so, and there was no e2e test to probe it

Author: mikehardy

packages/database/e2e/query/keepSynced.e2e.js

@@ -37,12 +37,23 @@ describe('database().ref().keepSynced()', function () {
       }
     });
 
-    it('toggles keepSynced on and off without throwing', async function () {
+    it('toggles keepSynced on and off without throwing on supported platforms', async function () {
       if (Platform.other) return;
       const ref = firebase.database().ref('noop').orderByValue();
       await ref.keepSynced(true);
       await ref.keepSynced(false);
     });
+
+    it('keepSynced throws on unsupported platforms', async function () {
+      if (!Platform.other) return;
+      try {
+        await firebase.database().ref('noop').orderByValue().keepSynced(true);
+        throw new Error('did not throw');
+      } catch (error) {
+        error.code.should.containEql('unsupported');
+        error.message.should.containEql('This operation is not supported on this environment.');
+      }
+    });
   });
 
   describe('modular', function () {
@@ -58,13 +69,26 @@ describe('database().ref().keepSynced()', function () {
       }
     });
 
-    it('toggles keepSynced on and off without throwing', async function () {
+    it('toggles keepSynced on and off without throwing on supported platforms', async function () {
       if (Platform.other) return;
       const { getDatabase, ref, orderByValue, query, keepSynced } = databaseModular;
 
       const dbRef = query(ref(getDatabase(), 'noop'), orderByValue());
       await keepSynced(dbRef, true);
       await keepSynced(dbRef, false);
     });
+
+    it('keepSynced throws on unsupported platforms', async function () {
+      if (!Platform.other) return;
+      const { getDatabase, ref, orderByValue, query, keepSynced } = databaseModular;
+
+      try {
+        await keepSynced(query(ref(getDatabase(), 'noop'), orderByValue()), true);
+        throw new Error('did not throw');
+      } catch (error) {
+        error.code.should.containEql('unsupported');
+        error.message.should.containEql('This operation is not supported on this environment.');
+      }
+    });
   });
 });

packages/database/lib/web/RNFBDatabaseModule.js

@@ -22,6 +22,15 @@ import {
 import { guard, getWebError, emitEvent } from '@react-native-firebase/app/lib/internal/web/utils';
 import { getQueryInstance } from './query';
 
+function rejectWithCodeAndMessage(code, message) {
+  return Promise.reject(
+    getWebError({
+      code,
+      message,
+    }),
+  );
+}
+
 // Converts a DataSnapshot to an object.
 function snapshotToObject(snapshot) {
   const childKeys = [];
@@ -385,7 +394,7 @@ export default {
   },
 
   keepSynced() {
-    return rejectPromiseWithCodeAndMessage(
+    return rejectWithCodeAndMessage(
       'unsupported',
       'This operation is not supported on this environment.',
     );