chore(zero-client): Fix flaky test (#3711)

By exposing the underlying persist method to tests and use that

Author: arv

packages/zero-client/src/client/test-utils.ts

@@ -24,16 +24,17 @@ import type {
 import {upstreamSchema} from '../../../zero-protocol/src/up.ts';
 import type {Schema} from '../../../zero-schema/src/builder/schema-builder.ts';
 import * as ConnectionState from './connection-state-enum.ts';
+import type {CustomMutatorDefs} from './custom.ts';
 import type {LogOptions} from './log-options.ts';
 import type {ZeroOptions} from './options.ts';
 import {
   type TestingContext,
   Zero,
   createLogOptionsSymbol,
   exposedToTestingSymbol,
+  getInternalReplicacheImplForTesting,
   onSetConnectionStateSymbol,
 } from './zero.ts';
-import type {CustomMutatorDefs} from './custom.ts';
 
 type ConnectionState = Enum<typeof ConnectionState>;
 type ErrorKind = Enum<typeof ErrorKind>;
@@ -204,6 +205,11 @@ export class TestZero<
     assert(TESTING);
     this[exposedToTestingSymbol].setReload(r);
   }
+
+  persist(): Promise<void> {
+    assert(TESTING);
+    return getInternalReplicacheImplForTesting(this).persist();
+  }
 }
 
 declare const TESTING: boolean;

packages/zero-client/src/client/zero.test.ts

@@ -58,7 +58,6 @@ import {
   RUN_LOOP_INTERVAL_MS,
 } from './zero.ts';
 
-let realSetTimeout: typeof setTimeout;
 let clock: sinon.SinonFakeTimers;
 const startTime = 1678829450000;
 
@@ -68,7 +67,6 @@ let fetchStub: sinon.SinonStub<
 >;
 
 beforeEach(() => {
-  realSetTimeout = setTimeout;
   clock = sinon.useFakeTimers();
   clock.setSystemTime(startTime);
   sinon.replace(
@@ -2248,21 +2246,20 @@ test('kvStore option', async () => {
         ],
       }),
     });
-    const idIsAView = r.query.e.where('id', '=', 'a').materialize();
-    const allDataView = r.query.e.materialize();
 
-    // Firefox is flaky... it takes longer time than Chromium and WebKit.
-    // We therefore give it a few times to pass the expectation.
+    // Use persist as a way to ensure we have read the data out of IDB.
+    await r.persist();
 
-    await tickAFewTimes(clock);
-    await new Promise(resolve => realSetTimeout(resolve, 100));
+    const idIsAView = r.query.e.where('id', '=', 'a').materialize();
+    const allDataView = r.query.e.materialize();
     expect(allDataView.data).deep.equal(expectedValue);
+
     await r.mutate.e.insert({id: 'a', value: 1});
-    await tickAFewTimes(clock);
 
     expect(idIsAView.data).deep.equal([{id: 'a', value: 1}]);
     // Wait for persist to finish
-    await tickAFewTimes(clock, 2000);
+    await r.persist();
+
     await r.close();
     expect(spy.called).equal(expectedIDBOpenCalled, 'IDB existed!');
 

packages/zero-client/src/client/zero.ts

@@ -246,11 +246,11 @@ export interface ReplicacheInternalAPI {
 
 const internalReplicacheImplMap = new WeakMap<object, ReplicacheImpl>();
 
-export function getInternalReplicacheImplForTesting<
-  MD extends MutatorDefs,
-  S extends Schema,
->(z: Zero<S>): ReplicacheImpl<MD> {
-  return must(internalReplicacheImplMap.get(z)) as ReplicacheImpl<MD>;
+export function getInternalReplicacheImplForTesting(
+  z: object,
+): ReplicacheImpl<MutatorDefs> {
+  assert(TESTING);
+  return must(internalReplicacheImplMap.get(z));
 }
 
 export class Zero<