feat: Simplify FlagsmithCache interface

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
     }
 }