test: add negative test to detect replication failures

packages/client-sdk-nodejs/test/integration/shared/cache/replica-reads.test.ts

@@ -0,0 +1,10 @@
+import {runReplicaReadTests} from '@gomomento/common-integration-tests';
+import {SetupIntegrationTest} from '../../integration-setup';
+
+const {cacheClientWithBalancedReadConcern, integrationTestCacheName} =
+  SetupIntegrationTest();
+
+runReplicaReadTests(
+  cacheClientWithBalancedReadConcern,
+  integrationTestCacheName
+);

packages/client-sdk-web/test/integration/shared/cache/replica-reads.test.ts

@@ -0,0 +1,10 @@
+import {runReplicaReadTests} from '@gomomento/common-integration-tests';
+import {SetupIntegrationTest} from '../../integration-setup';
+
+const {cacheClientWithBalancedReadConcern, integrationTestCacheName} =
+  SetupIntegrationTest();
+
+runReplicaReadTests(
+  cacheClientWithBalancedReadConcern,
+  integrationTestCacheName
+);

packages/common-integration-tests/src/cache/replica-reads.ts

@@ -0,0 +1,61 @@
+import {v4} from 'uuid';
+import {CacheGet, CacheSet} from '@gomomento/sdk-core';
+import {expectWithMessage} from '../common-int-test-utils';
+import {ICacheClient} from '@gomomento/sdk-core/dist/src/internal/clients/cache';
+
+export function runReplicaReadTests(
+  cacheClientWithBalancedReadConcern: ICacheClient,
+  integrationTestCacheName: string
+) {
+  describe('Replica Read Tests', () => {
+    it('should read the latest value after replication delay using balanced read concern', async () => {
+      const client = cacheClientWithBalancedReadConcern;
+      const numTrials = 10;
+      const delayBetweenTrials = 100;
+      const replicationDelayMs = 1000;
+      const trials = [];
+
+      const trialFn = async (trialNumber: number) => {
+        // Start this trial at it's own time plus a random delay
+        const startDelay =
+          trialNumber * delayBetweenTrials + (Math.random() - 0.5) * 10;
+        await new Promise(resolve => setTimeout(resolve, startDelay));
+
+        const cacheKey = v4();
+        const cacheValue = v4();
+
+        // Perform a set operation
+        const setResponse = await client.set(
+          integrationTestCacheName,
+          cacheKey,
+          cacheValue
+        );
+        expectWithMessage(() => {
+          expect(setResponse).toBeInstanceOf(CacheSet.Success);
+        }, `expected SUCCESS but got ${setResponse.toString()}`);
+
+        // Wait for replication to complete
+        await new Promise(resolve => setTimeout(resolve, replicationDelayMs));
+
+        // Verify that the value can be read
+        const getResponse = await client.get(
+          integrationTestCacheName,
+          cacheKey
+        );
+        expectWithMessage(() => {
+          expect(getResponse).toBeInstanceOf(CacheGet.Hit);
+        }, `expected HIT but got ${getResponse.toString()}`);
+
+        expectWithMessage(() => {
+          expect(getResponse.value()).toEqual(cacheValue);
+        }, `expected ${cacheValue} but got ${getResponse.value() ?? 'undefined'}`);
+      };
+
+      for (let i = 0; i < numTrials; i++) {
+        trials.push(trialFn(i));
+      }
+
+      await Promise.all(trials);
+    });
+  });
+}

packages/common-integration-tests/src/index.ts

@@ -14,4 +14,5 @@ export * from './cache/update-ttl';
 export * from './leaderboard/leaderboard-client';
 export * from './webhooks/webhooks';
 export * from './cache/batch-get-set';
+export * from './cache/replica-reads';
 export * from './storage/storage';