Test with spies

packages/backend-core/src/cache/docWritethrough.ts

@@ -1,11 +1,11 @@
+import { AnyDocument, Database, LockName, LockType } from "@budibase/types"
 import BaseCache from "./base"
 import { getDocWritethroughClient } from "../redis/init"
-import { AnyDocument, Database, LockName, LockType } from "@budibase/types"
 
 import { JobQueue, createQueue } from "../queue"
 import * as dbUtils from "../db"
 import { Duration, newid } from "../utils"
-import { context, locks } from ".."
+import { locks } from ".."
 
 let CACHE: BaseCache | null = null
 async function getCache() {
@@ -36,6 +36,8 @@ export const docWritethroughProcessorQueue = createQueue<ProcessDocMessage>(
   }
 )
 
+class DocWritethroughProcessor {
+  init() {
     docWritethroughProcessorQueue.process(async message => {
       const { cacheKeyPrefix, messageId } = message.data
 
@@ -64,7 +66,7 @@ docWritethroughProcessorQueue.process(async message => {
             return
           }
 
-      await persistToDb(cache, message.data)
+          await this.persistToDb(cache, message.data)
           console.log("DocWritethrough persisted", { data: message.data })
 
           await cache.deleteIfValue(
@@ -78,8 +80,10 @@ docWritethroughProcessorQueue.process(async message => {
         throw new Error(`Ignoring redlock conflict in write-through cache`)
       }
     })
+    return this
+  }
 
-export async function persistToDb(
+  private async persistToDb(
     cache: BaseCache,
     {
       dbName,
@@ -113,6 +117,9 @@ export async function persistToDb(
       await cache.delete(key, { useTenancy: false })
     }
   }
+}
+
+export const processor = new DocWritethroughProcessor().init()
 
 export class DocWritethrough {
   private db: Database

packages/backend-core/src/cache/tests/docWritethrough.spec.ts

@@ -1,12 +1,11 @@
+import _ from "lodash"
 import { DBTestConfiguration, generator, structures } from "../../../tests"
 import { getDB } from "../../db"
-import _ from "lodash"
 
-import {
+import { DocWritethrough, processor } from "../docWritethrough"
-  DocWritethrough,
+
-  docWritethroughProcessorQueue,
-} from "../docWritethrough"
 import InMemoryQueue from "../../queue/inMemoryQueue"
+import { docWritethroughProcessorQueue } from "../docWritethrough"
 
 const WRITE_RATE_MS = 1000
 
@@ -240,12 +239,13 @@ describe("docWritethrough", () => {
           )
         )
       }
-
+      const persistToDbSpy = jest.spyOn(processor as any, "persistToDb")
       const storeToCacheSpy = jest.spyOn(docWritethrough as any, "storeToCache")
 
       await config.doInTenant(async () => {
         await parallelPatch(5)
         expect(storeToCacheSpy).toBeCalledTimes(5)
+        expect(persistToDbSpy).not.toBeCalled()
         expect(await db.exists(documentId)).toBe(false)
 
         await travelForward(WRITE_RATE_MS)
@@ -253,7 +253,7 @@ describe("docWritethrough", () => {
         await parallelPatch(40)
 
         expect(storeToCacheSpy).toBeCalledTimes(45)
-
+        expect(persistToDbSpy).toBeCalledTimes(1)
         // Ideally we want to spy on persistToDb from ./docWritethrough, but due our barrel files configuration required quite of a complex setup.
         // We are relying on the document being stored only once (otherwise we would have _rev updated)
         expect(await db.get(documentId)).toEqual(