DefinitelyTyped · jgabriel98 · Nov 4, 2025 · Nov 4, 2025 · Nov 4, 2025 · Nov 4, 2025
diff --git a/types/instafeed.js/index.d.ts b/types/instafeed.js/index.d.ts
@@ -19,8 +19,8 @@ declare namespace Instafeed {
         apiLimit?: number;
         before?: () => void;
         debug?: boolean;
-        error?: (err: unknown) => any;
-        filter?: (item: InstagramDataItem) => boolean;
+        error?: (err: Error) => any;
+        filter?: (item: T) => boolean;
         limit?: number;
         mock?: boolean;
         render?: (item: T, options: Instafeed.InstafeedOptions) => string;
@@ -29,30 +29,39 @@ declare namespace Instafeed {
         target?: string | Element;
         template?: string;
         templateBoundaries?: string[];
-        transform?: (item: InstagramDataItem) => Record<string, unknown>;
+        transform?: (item: InstafeedDefaultItem) => T;
     }
 
     interface InstafeedDefaultItem {
         caption: string;
-        tags: string[];
         id: string;
         image: string;
         link: string;
         model: InstagramDataItem;
+        tags: string[];
         timestamp: string;
         type: string;
         username: string;
     }
 
-    interface InstagramDataItem {
+    type InstagramDataItem = {
         caption: string;
         id: string;
-        media_type: string;
+        media_type: "CAROUSEL_ALBUM" | "IMAGE";
         media_url: string;
         permalink: string;
         timestamp: string;
         username: string;
-    }
+    } | {
+        caption: string;
+        id: string;
+        media_type: "VIDEO";
+        media_url: string;
+        permalink: string;
+        thumbnail_url: string;
+        timestamp: string;
+        username: string;
+    };
 
     interface InstagramPaging {
         cursors: {

diff --git a/types/instafeed.js/instafeed.js-tests.ts b/types/instafeed.js/instafeed.js-tests.ts
@@ -1,4 +1,5 @@
 import Instafeed = require("instafeed.js");
+import { type InstafeedDefaultItem } from "instafeed.js";
 
 // $ExpectType Instafeed<InstafeedDefaultItem>
 new Instafeed({ accessToken: "aa" });
@@ -11,3 +12,29 @@ new Instafeed({});
 
 // @ts-expect-error
 new Instafeed();
+
+// test if transform return type is passed to other hooks
+new Instafeed({
+    accessToken: "aa",
+    transform(item) {
+        return { ...item, extra: "foo" };
+    },
+    filter(item) {
+        // $ExpectType string
+        item.extra;
+        return true;
+    },
+});
+
+interface CustomInstafeedItem extends InstafeedDefaultItem {
+    extra: string;
+}
+
+// test if omiting expected extra field breaks compiler as expected
+new Instafeed<CustomInstafeedItem>({
+    accessToken: "aa",
+    // @ts-expect-error
+    transform(item) {
+        return item;
+    },
+});