Improve handling of animated GIF and WEBP images (#8153)

test/Image-test.ts

@@ -0,0 +1,61 @@
+/*
+Copyright 2022 The Matrix.org Foundation C.I.C.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+import fs from "fs";
+import path from "path";
+
+import './skinned-sdk';
+import { blobIsAnimated, mayBeAnimated } from "../src/utils/Image";
+
+describe("Image", () => {
+    describe("mayBeAnimated", () => {
+        it("image/gif", async () => {
+            expect(mayBeAnimated("image/gif")).toBeTruthy();
+        });
+        it("image/webp", async () => {
+            expect(mayBeAnimated("image/webp")).toBeTruthy();
+        });
+        it("image/png", async () => {
+            expect(mayBeAnimated("image/png")).toBeFalsy();
+        });
+        it("image/jpeg", async () => {
+            expect(mayBeAnimated("image/jpeg")).toBeFalsy();
+        });
+    });
+
+    describe("blobIsAnimated", () => {
+        const animatedGif = new Blob([fs.readFileSync(path.resolve(__dirname, "images", "animated-logo.gif"))]);
+        const animatedWebp = new Blob([fs.readFileSync(path.resolve(__dirname, "images", "animated-logo.webp"))]);
+        const staticGif = new Blob([fs.readFileSync(path.resolve(__dirname, "images", "static-logo.gif"))]);
+        const staticWebp = new Blob([fs.readFileSync(path.resolve(__dirname, "images", "static-logo.webp"))]);
+
+        it("Animated GIF", async () => {
+            expect(await blobIsAnimated("image/gif", animatedGif)).toBeTruthy();
+        });
+
+        it("Static GIF", async () => {
+            expect(await blobIsAnimated("image/gif", staticGif)).toBeFalsy();
+        });
+
+        it("Animated WEBP", async () => {
+            expect(await blobIsAnimated("image/webp", animatedWebp)).toBeTruthy();
+        });
+
+        it("Static WEBP", async () => {
+            expect(await blobIsAnimated("image/webp", staticWebp)).toBeFalsy();
+        });
+    });
+});