fix fetch from api after loading stale cache when skip api set

Flagsmith · Sep 17, 2024 · cba3282 · cba3282
1 parent 2f4bbbb
commit cba3282
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Showing 2 changed files with 26 additions and 2 deletions.
diff --git a/flagsmith-core.ts b/flagsmith-core.ts
@@ -404,6 +404,7 @@ const Flagsmith = class {
                             try {
                                 const json = JSON.parse(res);
                                 let cachePopulated = false;
+                                let staleCachePopulated = false;
                                 if (json && json.api === this.api && json.environmentID === this.environmentID) {
                                     let setState = true;
                                     if (this.identity && (json.identity !== this.identity)) {
@@ -418,6 +419,7 @@ const Flagsmith = class {
                                             }
                                             else if (json.ts && this.cacheOptions.loadStale) {
                                                 this.log("Loading stale cache, timestamp ts:" + json.ts + " ttl: " + this.cacheOptions.ttl + " time elapsed since cache: " + (new Date().valueOf()-json.ts)+"ms")
+                                                staleCachePopulated = true;
                                                 setState = true;
                                             }
                                         }
@@ -439,13 +441,17 @@ const Flagsmith = class {
                                 }
 
                                 if (cachePopulated) { // retrieved flags from local storage
-                                    const shouldFetchFlags = !preventFetch && (!this.cacheOptions.skipAPI||!cachePopulated)
+                                    const shouldFetchFlags = !preventFetch && (
+                                        !this.cacheOptions.skipAPI ||
+                                        !cachePopulated ||
+                                        (cachePopulated && staleCachePopulated)
+                                    )
                                     this._onChange(null,
                                         { isFromServer: false, flagsChanged, traitsChanged },
                                         this._loadedState(null, FlagSource.CACHE, shouldFetchFlags)
                                     );
                                     this.oldFlags = this.flags;
-                                    if (this.cacheOptions.skipAPI && cachePopulated) {
+                                    if (this.cacheOptions.skipAPI && cachePopulated && !staleCachePopulated) {
                                         this.log("Skipping API, using cache")
                                     }
                                     if (shouldFetchFlags) {

diff --git a/test/cache.test.ts b/test/cache.test.ts
@@ -201,6 +201,24 @@ describe('Cache', () => {
             ...defaultStateAlt,
         });
     });
+    test('should get flags from API when stale cache is loaded and skipAPI is set', async () => {
+        const onChange = jest.fn();
+        const { flagsmith, initConfig, AsyncStorage, mockFetch } = getFlagsmith({
+            cacheFlags: true,
+            onChange,
+            cacheOptions: { ttl: 1, skipAPI: true, loadStale: true },
+        });
+        await AsyncStorage.setItem('BULLET_TRAIN_DB', JSON.stringify({
+            ...defaultStateAlt,
+            ts: new Date().valueOf() - 100,
+        }));
+        await flagsmith.init(initConfig);
+        expect(onChange).toHaveBeenCalledTimes(1);
+        expect(mockFetch).toHaveBeenCalledTimes(1);
+        expect(getStateToCheck(flagsmith.getState())).toEqual({
+            ...defaultStateAlt,
+        });
+    });
     test('should validate flags are unchanged when fetched', async () => {
         const onChange = jest.fn();
         const { flagsmith, initConfig, AsyncStorage, mockFetch } = getFlagsmith({