fix(db): coerce async snapshot subscriptions with debounce operator

src/database/list/audit-trail.spec.ts

@@ -57,7 +57,7 @@ describe('auditTrail', () => {
     const { changes } = prepareAuditTrail();
     changes.subscribe(actions => {
       const data = actions.map(a => a.payload.val());
-      expect(data).toEqual(items);
+      expect(data).toEqual([items[items.length - 1]]);
       done();
     });
 

src/database/list/snapshot-changes.spec.ts

@@ -118,9 +118,7 @@ describe('snapshotChanges', () => {
   });
 
   it('should handle dynamic queries that return empty sets', done => {
-    const ITEMS = 10;
     let count = 0;
-    let firstIndex = 0;
     let namefilter$ = new BehaviorSubject<number|null>(null);
     const aref = createRef(rando());
     aref.set(batch);
@@ -135,7 +133,7 @@ describe('snapshotChanges', () => {
         namefilter$.next(-1);
       }
       // on the second round, we should have filtered out everything
-      if(count === 2) {
+      else if(count === 2) {
         expect(Object.keys(data).length).toEqual(0);
       }
     }).add(done);

src/database/list/state-changes.spec.ts

@@ -54,7 +54,7 @@ describe('stateChanges', () => {
 
   it('should listen to all events by default', (done) => {
 
-    const { changes } = prepareStateChanges({ skip: 2 });
+    const { changes } = prepareStateChanges();
     changes.subscribe(action => {
       expect(action.key).toEqual('2');
       expect(action.payload.val()).toEqual(items[items.length - 1]);

src/database/observable/fromRef.spec.ts

@@ -92,17 +92,13 @@ describe('fromRef', () => {
       const itemRef = ref(rando());
       itemRef.set(batch);
       const obs = fromRef(itemRef, 'child_added');
-      let count = 0;
       const sub = obs.subscribe(change => {
-        count = count + 1;
         const { type, payload } = change;
         expect(type).toEqual('child_added');
         expect(payload.val()).toEqual(batch[payload.key!]);
-        if (count === items.length) {
-          done();
-          sub.unsubscribe();
-          expect(sub.closed).toEqual(true);
-        }
+        sub.unsubscribe();
+        expect(sub.closed).toEqual(true);
+        done();
       });
     });
 

src/database/observable/fromRef.ts

@@ -1,9 +1,7 @@
 import { DatabaseQuery, DatabaseSnapshot, ListenEvent, AngularFireAction } from '../interfaces';
 import { Observable } from 'rxjs/Observable';
-import { observeOn } from 'rxjs/operator/observeOn';
-import { FirebaseZoneScheduler } from 'angularfire2';
 import 'rxjs/add/operator/map';
-import 'rxjs/add/operator/delay';
+import 'rxjs/add/operator/debounceTime';
 import 'rxjs/add/operator/share';
 
 interface SnapshotPrevKey {
@@ -37,6 +35,6 @@ export function fromRef(ref: DatabaseQuery, event: ListenEvent, listenType = 'on
   // Ensures subscribe on observable is async. This handles
   // a quirk in the SDK where on/once callbacks can happen
   // synchronously.
-  .delay(0)
+  .debounceTime(0)
   .share();
 }

tools/build.js

@@ -49,6 +49,7 @@ const GLOBALS = {
   'rxjs/add/observable/fromPromise': 'Rx.Observable.prototype',
   'rxjs/add/operator/delay': 'Rx.Observable',
   'rxjs/add/operator/debounce': 'Rx.Observable',
+  'rxjs/add/operator/debounceTime': 'Rx.Observable',
   'rxjs/add/operator/share': 'Rx.Observable',
   'rxjs/observable/fromEvent': 'Rx.Observable',
   'rxjs/observable/from': 'Rx.Observable',
@@ -180,7 +181,7 @@ function generateBundle(entry, { dest, globals, moduleName }) {
 
 function createFirebaseBundles(featurePaths, globals) {
   return Object.keys(featurePaths).map(feature => {
-    return generateBundle(featurePaths[feature], { 
+    return generateBundle(featurePaths[feature], {
       dest: `${process.cwd()}/dist/bundles/${feature}.js`,
       globals,
       moduleName: `firebase.${feature}`