New "readCache" that reads directly from redis cache (#38)

* New "readCache" that reads directly from redis * add test * unknown T * fix found: true * improve tests
soundxyz · Feb 16, 2023 · c0854d2 · c0854d2
1 parent ae354bd
commit c0854d2
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diff --git a/.changeset/slimy-carrots-prove.md b/.changeset/slimy-carrots-prove.md
@@ -0,0 +1,5 @@
+---
+"@soundxyz/fine-grained-cache": minor
+---
+
+New "readCache" that reads directly from redis cache
diff --git a/src/fineGrained.ts b/src/fineGrained.ts
@@ -67,7 +67,7 @@ export const Events = {
   REDLOCK_GET_AFTER_ACQUIRE: "REDLOCK_GET_AFTER_ACQUIRE",
 } as const;
 
-export type Events = typeof Events[keyof typeof Events];
+export type Events = (typeof Events)[keyof typeof Events];
 
 export type EventParamsObject = Record<string, string | number | boolean | null | undefined>;
 
@@ -805,7 +805,7 @@ export function FineGrainedCache({
     }
   }
 
-  async function setCache({
+  async function setCache<T = unknown>({
     populateMemoryCache = defaultUseMemoryCache,
     ttl,
     keys,
@@ -816,7 +816,7 @@ export function FineGrainedCache({
     ttl: StringValue | "Infinity";
     keys: string | [string, ...(string | number)[]];
     useSuperjson: boolean;
-    value: unknown;
+    value: T;
   }) {
     const key = generateCacheKey(keys);
 
@@ -870,12 +870,36 @@ export function FineGrainedCache({
     }
   }
 
+  function readCache<T = unknown>({
+    keys,
+    useSuperjson,
+  }: {
+    keys: string | [string, ...(string | number)[]];
+    useSuperjson: boolean;
+  }) {
+    const key = generateCacheKey(keys);
+
+    return getRedisCacheValue<Awaited<T>>(key, useSuperjson, false).then((value) => {
+      if (value === NotFoundSymbol) {
+        return {
+          found: false,
+        } as const;
+      }
+
+      return {
+        found: true,
+        value,
+      } as const;
+    });
+  }
+
   return {
     getCached,
     generateCacheKey,
     keyPrefix,
     memoryCache,
     invalidateCache,
     setCache,
+    readCache,
   };
 }
diff --git a/test/fineGrained.spec.ts b/test/fineGrained.spec.ts
@@ -1,7 +1,15 @@
 import test from "ava";
 import { join } from "path";
 import { CachedCallback, FineGrainedCache, LogEventArgs } from "../src";
-import { getCached, invalidateCache, logEverything, memoryCache, redis, setCache } from "./utils";
+import {
+  getCached,
+  invalidateCache,
+  logEverything,
+  memoryCache,
+  readCache,
+  redis,
+  setCache,
+} from "./utils";
 import { createDeferredPromise } from "../src/utils";
 import { setTimeout } from "timers/promises";
 import { addMinutes, minutesToSeconds } from "date-fns";
@@ -636,6 +644,17 @@ test("setCache - regular", async (t) => {
   const keys = "test";
   const ttl = "10 seconds" as const;
 
+  {
+    const cache = await readCache({
+      keys,
+      useSuperjson: false,
+    });
+
+    t.deepEqual<typeof cache, typeof cache>(cache, {
+      found: false,
+    });
+  }
+
   const value = 123;
 
   await setCache({
@@ -658,12 +677,35 @@ test("setCache - regular", async (t) => {
   );
 
   t.is(data, value);
+
+  {
+    const cache = await readCache({
+      keys,
+      useSuperjson: false,
+    });
+
+    t.deepEqual<typeof cache, typeof cache>(cache, {
+      found: true,
+      value,
+    });
+  }
 });
 
 test("setCache - superjson", async (t) => {
   const keys = "test";
   const ttl = "10 seconds" as const;
 
+  {
+    const cache = await readCache({
+      keys,
+      useSuperjson: true,
+    });
+
+    t.deepEqual<typeof cache, typeof cache>(cache, {
+      found: false,
+    });
+  }
+
   const value = 456;
 
   await setCache({
@@ -686,6 +728,18 @@ test("setCache - superjson", async (t) => {
   );
 
   t.is(data, value);
+
+  {
+    const cache = await readCache({
+      keys,
+      useSuperjson: true,
+    });
+
+    t.deepEqual<typeof cache, typeof cache>(cache, {
+      found: true,
+      value,
+    });
+  }
 });
 
 test("setCache - memory cache", async (t) => {

diff --git a/test/utils.ts b/test/utils.ts
@@ -5,16 +5,23 @@ export const redis = new Redis({
   port: 6389,
 });
 
-export const { memoryCache, getCached, invalidateCache, generateCacheKey, keyPrefix, setCache } =
-  FineGrainedCache({
-    redis,
-    logEvents: {
-      log: console.log,
-      events: {
-        MEMORY_CACHE_HIT: true,
-      },
+export const {
+  memoryCache,
+  getCached,
+  invalidateCache,
+  generateCacheKey,
+  keyPrefix,
+  setCache,
+  readCache,
+} = FineGrainedCache({
+  redis,
+  logEvents: {
+    log: console.log,
+    events: {
+      MEMORY_CACHE_HIT: true,
     },
-  });
+  },
+});
 
 export const logEverything: Required<LoggedEvents> = {
   EXECUTION_TIME: true,