Fix cache get() on absent encrypted value

Author: FluxCapacitor2

backend/src/db/repo/cache.ts

@@ -24,13 +24,15 @@ export class CacheRepo {
     await this.client.cache.delete({ where: { key } });
   }
 
-  async get(key: string): Promise<string> {
+  async get(key: string): Promise<string | null> {
     return (
-      await this.client.cache.findUnique({
-        where: { key, expiresAt: { gt: new Date() } },
-        select: { value: true },
-      })
-    )?.value;
+      (
+        await this.client.cache.findUnique({
+          where: { key, expiresAt: { gt: new Date() } },
+          select: { value: true },
+        })
+      )?.value ?? null
+    );
   }
 
   async set(key: string, value: string, expiresAt: Date) {
@@ -41,10 +43,11 @@ export class CacheRepo {
     });
   }
 
-  async getEncrypted(key: string) {
+  async getEncrypted(key: string): Promise<string | null> {
     const row = await this.client.cache.findUnique({
       where: { key, expiresAt: { gt: new Date() } },
     });
+    if (row === null) return null;
     if (!row.encryptionKey) {
       throw new Error("getEncrypted called on a row without an encryption key");
     }

backend/src/service/common/cache.ts

@@ -49,10 +49,7 @@ export class KVCacheService {
     await this.cacheRepo.remove(key);
   }
 
-  async get(
-    key: string,
-    encrypt: boolean = false,
-  ): Promise<string | undefined> {
+  async get(key: string, encrypt: boolean = false): Promise<string | null> {
     const localResult = this.localCache.get(key);
     if (localResult) {
       return Promise.resolve(localResult);
@@ -72,7 +69,7 @@ export class KVCacheService {
         : await this.cacheRepo.get(key);
     } catch (e) {
       logger.warn({ cacheKey: key, error: e }, "Failed to look up cache key");
-      return undefined;
+      return null;
     }
   }
 

backend/test/db/repo/cache.spec.ts

@@ -14,3 +14,10 @@ test("encrypted cached values", async () => {
 
   expect(value).toEqual("value");
 });
+
+test("get blank encrypted value", async () => {
+  const db = await createDB();
+
+  const value = await db.cache.getEncrypted("unknown_key");
+  expect(value).toBeNull();
+});