Add gif/webp utility tests

package.json

@@ -166,6 +166,7 @@
     "@wojtekmaj/enzyme-adapter-react-17": "^0.6.1",
     "allchange": "^1.0.6",
     "babel-jest": "^26.6.3",
+    "blob-polyfill": "^6.0.20211015",
     "chokidar": "^3.5.1",
     "concurrently": "^5.3.0",
     "enzyme": "^3.11.0",

src/utils/Image.ts

@@ -30,7 +30,7 @@ export async function blobIsAnimated(mimeType: string, blob: Blob): Promise<bool
     if (mimeType === "image/webp") {
         // Only extended file format WEBP images support animation, so grab the expected data range and verify header.
         // Based on https://developers.google.com/speed/webp/docs/riff_container#extended_file_format
-        const arr = await blob.slice(0, 16).arrayBuffer();
+        const arr = await blob.slice(0, 17).arrayBuffer();
         if (
             arrayBufferReadStr(arr, 0, 4) === "RIFF" &&
             arrayBufferReadStr(arr, 8, 4) === "WEBP" &&

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();
+        });
+    });
+});

test/setupTests.js

@@ -1,6 +1,7 @@
 import { TextEncoder, TextDecoder } from 'util';
 import Adapter from "@wojtekmaj/enzyme-adapter-react-17";
 import { configure } from "enzyme";
+import "blob-polyfill"; // https://github.com/jsdom/jsdom/issues/2555
 
 import * as languageHandler from "../src/languageHandler";
 import SdkConfig, { DEFAULTS } from '../src/SdkConfig';

yarn.lock

@@ -2627,6 +2627,11 @@ binary-extensions@^2.0.0:
   resolved "https://registry.yarnpkg.com/binary-extensions/-/binary-extensions-2.2.0.tgz#75f502eeaf9ffde42fc98829645be4ea76bd9e2d"
   integrity sha512-jDctJ/IVQbZoJykoeHbhXpOlNBqGNcwXJKJog42E5HDPUwQTSdjCHdihjj0DlnheQ7blbT6dHOafNAiS8ooQKA==
 
+blob-polyfill@^6.0.20211015:
+  version "6.0.20211015"
+  resolved "https://registry.yarnpkg.com/blob-polyfill/-/blob-polyfill-6.0.20211015.tgz#7c47e62347e302e8d1d1ee5e140b881f74bdb23e"
+  integrity sha512-OGL4bm6ZNpdFAvQugRlQy5MNly8gk15aWi/ZhQHimQsrx9WKD05r+v+xNgHCChLER3MH+9KLAhzuFlwFKrH1Yw==
+
 bluebird@^3.5.0:
   version "3.7.2"
   resolved "https://registry.yarnpkg.com/bluebird/-/bluebird-3.7.2.tgz#9f229c15be272454ffa973ace0dbee79a1b0c36f"