Merge pull request #165 from Flagsmith/feat/simplify-cache-interfac

feat: Simplify FlagsmithCache interface

package.json

@@ -1,6 +1,6 @@
 {
   "name": "flagsmith-nodejs",
-  "version": "4.0.0",
+  "version": "5.0.0",
   "description": "Flagsmith lets you manage features flags and remote config across web, mobile and server side applications. Deliver true Continuous Integration. Get builds out faster. Control who has access to new features.",
   "main": "./build/cjs/index.js",
   "type": "module",

sdk/index.ts

@@ -128,17 +128,6 @@ export class Flagsmith {
         }
 
         if (!!data.cache) {
-            const missingMethods: string[] = ['has', 'get', 'set'].filter(
-                method => data.cache && !data.cache[method]
-            );
-
-            if (missingMethods.length > 0) {
-                throw new Error(
-                    `Please implement the following methods in your cache: ${missingMethods.join(
-                        ', '
-                    )}`
-                );
-            }
             this.cache = data.cache;
         }
 

sdk/types.ts

@@ -5,11 +5,24 @@ import { Logger } from 'pino';
 import { BaseOfflineHandler } from './offline_handlers.js';
 
 export type IFlagsmithValue<T = string | number | boolean | null> = T;
+
+
+/**
+ * Stores and retrieves {@link Flags} from a cache.
+ */
 export interface FlagsmithCache {
-    get(key: string): Promise<Flags | undefined> | undefined;
-    set(key: string, value: Flags, ttl?: string | number): boolean | Promise<boolean>;
-    has(key: string): boolean | Promise<boolean>;
-    [key: string]: any;
+    /**
+     * Retrieve the cached {@link Flags} for the given environment or identity, or `undefined` if no cached value exists.
+     * @param key An environment ID or identity identifier, which is used as the cache key.
+     */
+    get(key: string): Promise<Flags | undefined>;
+
+    /**
+     * Persist an environment or identity's {@link Flags} in the cache.
+     * @param key An environment ID or identity identifier, which is used as the cache key.
+     * @param value The {@link Flags} to be stored in the cache.
+     */
+    set(key: string, value: Flags): Promise<void>;
 }
 
 export type Fetch = typeof fetch

tests/sdk/flagsmith-cache.test.ts

@@ -4,15 +4,6 @@ beforeEach(() => {
   vi.clearAllMocks();
 });
 
-test('test_wrong_cache_interface_throws_an_error', async () => {
-  const cache = {
-    set: () => { },
-    get: () => { },
-  };
-
-  expect(() => { const flg = flagsmith({ cache }); }).toThrow();
-});
-
 test('test_empty_cache_not_read_but_populated', async () => {
   fetch.mockResolvedValue(new Response(flagsJSON));
 
@@ -23,7 +14,7 @@ test('test_empty_cache_not_read_but_populated', async () => {
   const allFlags = (await flg.getEnvironmentFlags()).allFlags();
 
   expect(set).toBeCalled();
-  expect(await cache.has('flags')).toBe(true);
+  expect(await cache.get('flags')).toBeTruthy();
 
   expect(fetch).toBeCalledTimes(1);
   expect(allFlags[0].enabled).toBe(true);
@@ -42,7 +33,7 @@ test('test_api_not_called_when_cache_present', async () => {
   const allFlags = await (await flg.getEnvironmentFlags()).allFlags();
 
   expect(set).toBeCalled();
-  expect(await cache.has('flags')).toBe(true);
+  expect(await cache.get('flags')).toBeTruthy();
 
   expect(fetch).toBeCalledTimes(1);
   expect(allFlags[0].enabled).toBe(true);
@@ -97,7 +88,7 @@ test('test_cache_used_for_identity_flags', async () => {
   const identityFlags = (await flg.getIdentityFlags(identifier, traits)).allFlags();
 
   expect(set).toBeCalled();
-  expect(await cache.has('flags-identifier')).toBe(true);
+  expect(await cache.get('flags-identifier')).toBeTruthy();
 
   expect(fetch).toBeCalledTimes(1);
 
@@ -124,7 +115,7 @@ test('test_cache_used_for_identity_flags_local_evaluation', async () => {
   const identityFlags = (await flg.getIdentityFlags(identifier, traits)).allFlags();
 
   expect(set).toBeCalled();
-  expect(await cache.has('flags-identifier')).toBe(true);
+  expect(await cache.get('flags-identifier')).toBeTruthy();
 
   expect(fetch).toBeCalledTimes(1);
 

tests/sdk/utils.ts

@@ -10,17 +10,12 @@ const DATA_DIR = __dirname + '/data/';
 export class TestCache implements FlagsmithCache {
     cache: Record<string, Flags> = {};
 
-    async get(name: string): Promise<Flags> {
+    async get(name: string): Promise<Flags | undefined> {
         return this.cache[name];
     }
 
-    async has(name: string): Promise<boolean> {
-        return !!this.cache[name];
-    }
-
-    async set(name: string, value: Flags, ttl: number|string) {
+    async set(name: string, value: Flags) {
         this.cache[name] = value;
-        return true
     }
 }