Clarify default TTL behavior.

Signed-off-by: Eric Peterson <ericpeterson@spotify.com>

packages/backend-common/src/cache/CacheClient.test.ts

@@ -19,6 +19,7 @@ import cacheManager from 'cache-manager';
 
 describe('CacheClient', () => {
   const pluginId = 'test';
+  const defaultTtl = 60;
   let client: cacheManager.Cache;
   const b64 = (k: string) => Buffer.from(k).toString('base64');
 
@@ -33,7 +34,7 @@ describe('CacheClient', () => {
 
   describe('CacheClient.get', () => {
     it('calls client with normalized key', async () => {
-      const sut = new DefaultCacheClient({ client, pluginId });
+      const sut = new DefaultCacheClient({ client, defaultTtl, pluginId });
       const keyPartial = 'somekey';
 
       await sut.get(keyPartial);
@@ -42,7 +43,7 @@ describe('CacheClient', () => {
     });
 
     it('calls client with normalized key (very long key)', async () => {
-      const sut = new DefaultCacheClient({ client, pluginId });
+      const sut = new DefaultCacheClient({ client, defaultTtl, pluginId });
       const keyPartial = 'x'.repeat(251);
 
       await sut.get(keyPartial);
@@ -55,7 +56,7 @@ describe('CacheClient', () => {
 
     it('performs deserialization on returned data', async () => {
       const expectedValue = { some: 'value' };
-      const sut = new DefaultCacheClient({ client, pluginId });
+      const sut = new DefaultCacheClient({ client, defaultTtl, pluginId });
       client.get = jest.fn().mockResolvedValue(JSON.stringify(expectedValue));
 
       const actualValue = await sut.get('someKey');
@@ -64,7 +65,7 @@ describe('CacheClient', () => {
     });
 
     it('returns null on any underlying error', async () => {
-      const sut = new DefaultCacheClient({ client, pluginId });
+      const sut = new DefaultCacheClient({ client, defaultTtl, pluginId });
       client.get = jest.fn().mockRejectedValue(undefined);
 
       const actualValue = await sut.get('someKey');
@@ -75,7 +76,7 @@ describe('CacheClient', () => {
 
   describe('CacheClient.set', () => {
     it('calls client with normalized key', async () => {
-      const sut = new DefaultCacheClient({ client, pluginId });
+      const sut = new DefaultCacheClient({ client, defaultTtl, pluginId });
       const keyPartial = 'somekey';
 
       await sut.set(keyPartial, {});
@@ -86,7 +87,7 @@ describe('CacheClient', () => {
     });
 
     it('performs serialization on given data', async () => {
-      const sut = new DefaultCacheClient({ client, pluginId });
+      const sut = new DefaultCacheClient({ client, defaultTtl, pluginId });
       const expectedData = { some: 'value' };
 
       await sut.set('someKey', expectedData);
@@ -97,7 +98,7 @@ describe('CacheClient', () => {
     });
 
     it('passes ttl to client when given', async () => {
-      const sut = new DefaultCacheClient({ client, pluginId });
+      const sut = new DefaultCacheClient({ client, defaultTtl, pluginId });
       const expectedTtl = 3600;
 
       await sut.set('someKey', {}, { ttl: expectedTtl });
@@ -107,8 +108,18 @@ describe('CacheClient', () => {
       expect(actualOptions.ttl).toEqual(expectedTtl);
     });
 
+    it('passes defaultTtl to client when not', async () => {
+      const sut = new DefaultCacheClient({ client, defaultTtl, pluginId });
+
+      await sut.set('someKey', {});
+
+      const spy = client.set as jest.Mock;
+      const actualOptions = spy.mock.calls[0][2];
+      expect(actualOptions.ttl).toEqual(defaultTtl);
+    });
+
     it('does not throw errors on any client error', async () => {
-      const sut = new DefaultCacheClient({ client, pluginId });
+      const sut = new DefaultCacheClient({ client, defaultTtl, pluginId });
       client.set = jest.fn().mockRejectedValue(undefined);
 
       expect(async () => {
@@ -119,7 +130,7 @@ describe('CacheClient', () => {
 
   describe('CacheClient.delete', () => {
     it('calls client with normalized key', async () => {
-      const sut = new DefaultCacheClient({ client, pluginId });
+      const sut = new DefaultCacheClient({ client, defaultTtl, pluginId });
       const keyPartial = 'somekey';
 
       await sut.delete(keyPartial);
@@ -130,7 +141,7 @@ describe('CacheClient', () => {
     });
 
     it('does not throw errors on any client error', async () => {
-      const sut = new DefaultCacheClient({ client, pluginId });
+      const sut = new DefaultCacheClient({ client, defaultTtl, pluginId });
       client.del = jest.fn().mockRejectedValue(undefined);
 
       expect(async () => {

packages/backend-common/src/cache/CacheClient.ts

@@ -21,6 +21,7 @@ import { createHash } from 'crypto';
 type CacheClientArgs = {
   client: cacheManager.Cache;
   pluginId: string;
+  defaultTtl: number;
 };
 
 type CacheSetOptions = {
@@ -56,10 +57,12 @@ export interface CacheClient {
  */
 export class DefaultCacheClient implements CacheClient {
   private readonly client: cacheManager.Cache;
+  private readonly defaultTtl: number;
   private readonly pluginId: string;
 
-  constructor({ client, pluginId }: CacheClientArgs) {
+  constructor({ client, defaultTtl, pluginId }: CacheClientArgs) {
     this.client = client;
+    this.defaultTtl = defaultTtl;
     this.pluginId = pluginId;
   }
 
@@ -81,7 +84,9 @@ export class DefaultCacheClient implements CacheClient {
     const k = this.getNormalizedKey(key);
     try {
       const data = this.serializeData(value);
-      await this.client.set(k, data, opts.ttl ? { ttl: opts.ttl } : undefined);
+      await this.client.set(k, data, {
+        ttl: opts.ttl || this.defaultTtl,
+      });
     } catch {
       return;
     }

packages/backend-common/src/cache/CacheManager.ts

@@ -67,6 +67,7 @@ export class CacheManager {
         const concreteClient = this.getClientWithTtl(defaultTtl);
         return new DefaultCacheClient({
           client: concreteClient,
+          defaultTtl,
           pluginId: pluginId,
         });
       },