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

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/ContentMessages.ts

@@ -106,15 +106,17 @@ interface IThumbnail {
  * @param {HTMLElement} element The element to thumbnail.
  * @param {number} inputWidth The width of the image in the input element.
  * @param {number} inputHeight the width of the image in the input element.
- * @param {String} mimeType The mimeType to save the blob as.
+ * @param {string} mimeType The mimeType to save the blob as.
+ * @param {boolean} calculateBlurhash Whether to calculate a blurhash of the given image too.
  * @return {Promise} A promise that resolves with an object with an info key
  *  and a thumbnail key.
  */
-async function createThumbnail(
+export async function createThumbnail(
     element: ThumbnailableElement,
     inputWidth: number,
     inputHeight: number,
     mimeType: string,
+    calculateBlurhash = true,
 ): Promise<IThumbnail> {
     let targetWidth = inputWidth;
     let targetHeight = inputHeight;
@@ -152,7 +154,7 @@ async function createThumbnail(
 
     const imageData = context.getImageData(0, 0, targetWidth, targetHeight);
     // thumbnailPromise and blurhash promise are being awaited concurrently
-    const blurhash = await BlurhashEncoder.instance.getBlurhash(imageData);
+    const blurhash = calculateBlurhash ? await BlurhashEncoder.instance.getBlurhash(imageData) : undefined;
     const thumbnail = await thumbnailPromise;
 
     return {

src/components/views/messages/MImageBody.tsx

@@ -30,19 +30,25 @@ import SettingsStore from "../../../settings/SettingsStore";
 import InlineSpinner from '../elements/InlineSpinner';
 import { replaceableComponent } from "../../../utils/replaceableComponent";
 import { Media, mediaFromContent } from "../../../customisations/Media";
-import { BLURHASH_FIELD } from "../../../ContentMessages";
+import { BLURHASH_FIELD, createThumbnail } from "../../../ContentMessages";
 import { IMediaEventContent } from '../../../customisations/models/IMediaEventContent';
 import ImageView from '../elements/ImageView';
 import { IBodyProps } from "./IBodyProps";
 import { ImageSize, suggestedSize as suggestedImageSize } from "../../../settings/enums/ImageSize";
 import { MatrixClientPeg } from '../../../MatrixClientPeg';
 import RoomContext, { TimelineRenderingType } from "../../../contexts/RoomContext";
+import { blobIsAnimated, mayBeAnimated } from '../../../utils/Image';
+
+enum Placeholder {
+    NoImage,
+    Blurhash,
+}
 
 interface IState {
-    decryptedUrl?: string;
+    contentUrl?: string;
-    decryptedThumbnailUrl?: string;
+    thumbUrl?: string;
-    decryptedBlob?: Blob;
+    isAnimated?: boolean;
-    error;
+    error?: Error;
     imgError: boolean;
     imgLoaded: boolean;
     loadedImageDimensions?: {
@@ -51,7 +57,7 @@ interface IState {
     };
     hover: boolean;
     showImage: boolean;
-    placeholder: 'no-image' | 'blurhash';
+    placeholder: Placeholder;
 }
 
 @replaceableComponent("views.messages.MImageBody")
@@ -68,16 +74,11 @@ export default class MImageBody extends React.Component<IBodyProps, IState> {
         super(props);
 
         this.state = {
-            decryptedUrl: null,
-            decryptedThumbnailUrl: null,
-            decryptedBlob: null,
-            error: null,
             imgError: false,
             imgLoaded: false,
-            loadedImageDimensions: null,
             hover: false,
             showImage: SettingsStore.getValue("showImages"),
-            placeholder: 'no-image',
+            placeholder: Placeholder.NoImage,
         };
     }
 
@@ -86,7 +87,7 @@ export default class MImageBody extends React.Component<IBodyProps, IState> {
         if (this.unmounted) return;
         // Consider the client reconnected if there is no error with syncing.
         // This means the state could be RECONNECTING, SYNCING, PREPARED or CATCHUP.
-        const reconnected = syncState !== "ERROR" && prevState !== syncState;
+        const reconnected = syncState !== SyncState.Error && prevState !== syncState;
         if (reconnected && this.state.imgError) {
             // Load the image again
             this.setState({
@@ -110,7 +111,7 @@ export default class MImageBody extends React.Component<IBodyProps, IState> {
             }
 
             const content = this.props.mxEvent.getContent<IMediaEventContent>();
-            const httpUrl = this.getContentUrl();
+            const httpUrl = this.state.contentUrl;
             const params: Omit<ComponentProps<typeof ImageView>, "onFinished"> = {
                 src: httpUrl,
                 name: content.body?.length > 0 ? content.body : _t('Attachment'),
@@ -139,29 +140,24 @@ export default class MImageBody extends React.Component<IBodyProps, IState> {
         }
     };
 
-    private isGif = (): boolean => {
-        const content = this.props.mxEvent.getContent();
-        return content.info?.mimetype === "image/gif";
-    };
-
     private onImageEnter = (e: React.MouseEvent<HTMLImageElement>): void => {
         this.setState({ hover: true });
 
-        if (!this.state.showImage || !this.isGif() || SettingsStore.getValue("autoplayGifs")) {
+        if (!this.state.showImage || !this.state.isAnimated || SettingsStore.getValue("autoplayGifs")) {
             return;
         }
         const imgElement = e.currentTarget;
-        imgElement.src = this.getContentUrl();
+        imgElement.src = this.state.contentUrl;
     };
 
     private onImageLeave = (e: React.MouseEvent<HTMLImageElement>): void => {
         this.setState({ hover: false });
 
-        if (!this.state.showImage || !this.isGif() || SettingsStore.getValue("autoplayGifs")) {
+        if (!this.state.showImage || !this.state.isAnimated || SettingsStore.getValue("autoplayGifs")) {
             return;
         }
         const imgElement = e.currentTarget;
-        imgElement.src = this.getThumbUrl();
+        imgElement.src = this.state.thumbUrl ?? this.state.contentUrl;
     };
 
     private onImageError = (): void => {
@@ -175,7 +171,7 @@ export default class MImageBody extends React.Component<IBodyProps, IState> {
         this.clearBlurhashTimeout();
         this.props.onHeightChanged();
 
-        let loadedImageDimensions;
+        let loadedImageDimensions: IState["loadedImageDimensions"];
 
         if (this.image.current) {
             const { naturalWidth, naturalHeight } = this.image.current;
@@ -185,22 +181,17 @@ export default class MImageBody extends React.Component<IBodyProps, IState> {
         this.setState({ imgLoaded: true, loadedImageDimensions });
     };
 
-    protected getContentUrl(): string {
+    private getContentUrl(): string {
-        const content: IMediaEventContent = this.props.mxEvent.getContent();
         // During export, the content url will point to the MSC, which will later point to a local url
-        if (this.props.forExport) return content.url || content.file?.url;
+        if (this.props.forExport) return this.media.srcMxc;
-        if (this.media.isEncrypted) {
-            return this.state.decryptedUrl;
-        } else {
         return this.media.srcHttp;
     }
-    }
 
     private get media(): Media {
         return mediaFromContent(this.props.mxEvent.getContent());
     }
 
-    protected getThumbUrl(): string {
+    private getThumbUrl(): string {
         // FIXME: we let images grow as wide as you like, rather than capped to 800x600.
         // So either we need to support custom timeline widths here, or reimpose the cap, otherwise the
         // thumbnail resolution will be unnecessarily reduced.
@@ -210,46 +201,37 @@ export default class MImageBody extends React.Component<IBodyProps, IState> {
 
         const content = this.props.mxEvent.getContent<IMediaEventContent>();
         const media = mediaFromContent(content);
+        const info = content.info;
 
-        if (media.isEncrypted) {
+        if (info?.mimetype === "image/svg+xml" && media.hasThumbnail) {
-            // Don't use the thumbnail for clients wishing to autoplay gifs.
+            // Special-case to return clientside sender-generated thumbnails for SVGs, if any,
-            if (this.state.decryptedThumbnailUrl) {
+            // given we deliberately don't thumbnail them serverside to prevent billion lol attacks and similar.
-                return this.state.decryptedThumbnailUrl;
-            }
-            return this.state.decryptedUrl;
-        } else if (content.info && content.info.mimetype === "image/svg+xml" && media.hasThumbnail) {
-            // special case to return clientside sender-generated thumbnails for SVGs, if any,
-            // given we deliberately don't thumbnail them serverside to prevent
-            // billion lol attacks and similar
             return media.getThumbnailHttp(thumbWidth, thumbHeight, 'scale');
-        } else {
+        }
-            // we try to download the correct resolution
+
-            // for hi-res images (like retina screenshots).
+        // we try to download the correct resolution for hi-res images (like retina screenshots).
-            // synapse only supports 800x600 thumbnails for now though,
+        // Synapse only supports 800x600 thumbnails for now though,
-            // so we'll need to download the original image for this to work
+        // so we'll need to download the original image for this to work  well for now.
-            // well for now. First, let's try a few cases that let us avoid
+        // First, let's try a few cases that let us avoid downloading the original, including:
-            // downloading the original, including:
         //   - When displaying a GIF, we always want to thumbnail so that we can
         //     properly respect the user's GIF autoplay setting (which relies on
         //     thumbnailing to produce the static preview image)
         //   - On a low DPI device, always thumbnail to save bandwidth
         //   - If there's no sizing info in the event, default to thumbnail
-            const info = content.info;
         if (
-                this.isGif() ||
+            this.state.isAnimated ||
             window.devicePixelRatio === 1.0 ||
             (!info || !info.w || !info.h || !info.size)
         ) {
             return media.getThumbnailOfSourceHttp(thumbWidth, thumbHeight);
-            } else {
+        }
-                // we should only request thumbnails if the image is bigger than 800x600
+
-                // (or 1600x1200 on retina) otherwise the image in the timeline will just
+        // We should only request thumbnails if the image is bigger than 800x600 (or 1600x1200 on retina) otherwise
-                // end up resampled and de-retina'd for no good reason.
+        // the image in the timeline will just end up resampled and de-retina'd for no good reason.
-                // Ideally the server would pregen 1600x1200 thumbnails in order to provide retina
+        // Ideally the server would pre-gen 1600x1200 thumbnails in order to provide retina thumbnails,
-                // thumbnails, but we don't do this currently in synapse for fear of disk space.
+        // but we don't do this currently in synapse for fear of disk space.
-                // As a compromise, let's switch to non-retina thumbnails only if the original
+        // As a compromise, let's switch to non-retina thumbnails only if the original image is both
-                // image is both physically too large and going to be massive to load in the
+        // physically too large and going to be massive to load in the timeline (e.g. >1MB).
-                // timeline (e.g. >1MB).
 
         const isLargerThanThumbnail = (
             info.w > thumbWidth ||
@@ -258,38 +240,74 @@ export default class MImageBody extends React.Component<IBodyProps, IState> {
         const isLargeFileSize = info.size > 1 * 1024 * 1024; // 1mb
 
         if (isLargeFileSize && isLargerThanThumbnail) {
-                    // image is too large physically and bytewise to clutter our timeline so
+            // image is too large physically and byte-wise to clutter our timeline so,
             // we ask for a thumbnail, despite knowing that it will be max 800x600
             // despite us being retina (as synapse doesn't do 1600x1200 thumbs yet).
             return media.getThumbnailOfSourceHttp(thumbWidth, thumbHeight);
-                } else {
+        }
-                    // download the original image otherwise, so we can scale it client side
+
-                    // to take pixelRatio into account.
+        // download the original image otherwise, so we can scale it client side to take pixelRatio into account.
         return media.srcHttp;
     }
+
+    private async downloadImage() {
+        if (this.state.contentUrl) return; // already downloaded
+
+        let thumbUrl: string;
+        let contentUrl: string;
+        if (this.props.mediaEventHelper.media.isEncrypted) {
+            try {
+                ([contentUrl, thumbUrl] = await Promise.all([
+                    this.props.mediaEventHelper.sourceUrl.value,
+                    this.props.mediaEventHelper.thumbnailUrl.value,
+                ]));
+            } catch (error) {
+                if (this.unmounted) return;
+                logger.warn("Unable to decrypt attachment: ", error);
+                // Set a placeholder image when we can't decrypt the image.
+                this.setState({ error });
+            }
+        } else {
+            thumbUrl = this.getThumbUrl();
+            contentUrl = this.getContentUrl();
+        }
+
+        const content = this.props.mxEvent.getContent<IMediaEventContent>();
+        let isAnimated = mayBeAnimated(content.info?.mimetype);
+
+        // If there is no included non-animated thumbnail then we will generate our own, we can't depend on the server
+        // because 1. encryption and 2. we can't ask the server specifically for a non-animated thumbnail.
+        if (isAnimated && !SettingsStore.getValue("autoplayGifs")) {
+            if (!thumbUrl || !content?.info.thumbnail_info || mayBeAnimated(content.info.thumbnail_info.mimetype)) {
+                const img = document.createElement("img");
+                const loadPromise = new Promise((resolve, reject) => {
+                    img.onload = resolve;
+                    img.onerror = reject;
+                });
+                img.crossOrigin = "Anonymous"; // CORS allow canvas access
+                img.src = contentUrl;
+
+                await loadPromise;
+
+                const blob = await this.props.mediaEventHelper.sourceBlob.value;
+                if (!await blobIsAnimated(content.info.mimetype, blob)) {
+                    isAnimated = false;
+                }
+
+                if (isAnimated) {
+                    const thumb = await createThumbnail(img, img.width, img.height, content.info.mimetype, false);
+                    thumbUrl = URL.createObjectURL(thumb.thumbnail);
                 }
             }
         }
 
-    private async downloadImage() {
-        if (this.props.mediaEventHelper.media.isEncrypted && this.state.decryptedUrl === null) {
-            try {
-                const thumbnailUrl = await this.props.mediaEventHelper.thumbnailUrl.value;
-                this.setState({
-                    decryptedUrl: await this.props.mediaEventHelper.sourceUrl.value,
-                    decryptedThumbnailUrl: thumbnailUrl,
-                    decryptedBlob: await this.props.mediaEventHelper.sourceBlob.value,
-                });
-            } catch (err) {
         if (this.unmounted) return;
-                logger.warn("Unable to decrypt attachment: ", err);
-                // Set a placeholder image when we can't decrypt the image.
         this.setState({
-                    error: err,
+            contentUrl,
+            thumbUrl,
+            isAnimated,
         });
     }
-        }
-    }
 
     private clearBlurhashTimeout() {
         if (this.timeout) {
@@ -317,7 +335,7 @@ export default class MImageBody extends React.Component<IBodyProps, IState> {
             this.timeout = setTimeout(() => {
                 if (!this.state.imgLoaded || !this.state.imgError) {
                     this.setState({
-                        placeholder: 'blurhash',
+                        placeholder: Placeholder.Blurhash,
                     });
                 }
             }, 150);
@@ -333,6 +351,9 @@ export default class MImageBody extends React.Component<IBodyProps, IState> {
         MatrixClientPeg.get().removeListener(ClientEvent.Sync, this.onClientSync);
         this.clearBlurhashTimeout();
         SettingsStore.unwatchSetting(this.sizeWatcher);
+        if (this.state.isAnimated && this.state.thumbUrl) {
+            URL.revokeObjectURL(this.state.thumbUrl);
+        }
     }
 
     protected messageContent(
@@ -341,10 +362,12 @@ export default class MImageBody extends React.Component<IBodyProps, IState> {
         content: IMediaEventContent,
         forcedHeight?: number,
     ): JSX.Element {
+        if (!thumbUrl) thumbUrl = contentUrl; // fallback
+
         let infoWidth: number;
         let infoHeight: number;
 
-        if (content && content.info && content.info.w && content.info.h) {
+        if (content.info?.w && content.info?.h) {
             infoWidth = content.info.w;
             infoHeight = content.info.h;
         } else {
@@ -385,9 +408,9 @@ export default class MImageBody extends React.Component<IBodyProps, IState> {
             forcedHeight ?? this.props.maxImageHeight,
         );
 
-        let img = null;
+        let img: JSX.Element;
-        let placeholder = null;
+        let placeholder: JSX.Element;
-        let gifLabel = null;
+        let gifLabel: JSX.Element;
 
         if (!this.props.forExport && !this.state.imgLoaded) {
             placeholder = this.getPlaceholder(maxWidth, maxHeight);
@@ -427,7 +450,8 @@ export default class MImageBody extends React.Component<IBodyProps, IState> {
             showPlaceholder = false; // because we're hiding the image, so don't show the placeholder.
         }
 
-        if (this.isGif() && !SettingsStore.getValue("autoplayGifs") && !this.state.hover) {
+        if (this.state.isAnimated && !SettingsStore.getValue("autoplayGifs") && !this.state.hover) {
+            // XXX: Arguably we may want a different label when the animated image is WEBP and not GIF
             gifLabel = <p className="mx_MImageBody_gifLabel">GIF</p>;
         }
 
@@ -489,9 +513,9 @@ export default class MImageBody extends React.Component<IBodyProps, IState> {
         const blurhash = this.props.mxEvent.getContent().info?.[BLURHASH_FIELD];
 
         if (blurhash) {
-            if (this.state.placeholder === 'no-image') {
+            if (this.state.placeholder === Placeholder.NoImage) {
                 return <div className="mx_no-image-placeholder" style={{ width: width, height: height }} />;
-            } else if (this.state.placeholder === 'blurhash') {
+            } else if (this.state.placeholder === Placeholder.Blurhash) {
                 return <Blurhash className="mx_Blurhash" hash={blurhash} width={width} height={height} />;
             }
         }
@@ -510,13 +534,15 @@ export default class MImageBody extends React.Component<IBodyProps, IState> {
         if (this.props.forExport) return null;
         /*
          * In the room timeline or the thread context we don't need the download
-         * link as the message action bar will fullfil that
+         * link as the message action bar will fulfill that
          */
-        const hasMessageActionBar = this.context.timelineRenderingType === TimelineRenderingType.Room
+        const hasMessageActionBar = (
-            || this.context.timelineRenderingType === TimelineRenderingType.Pinned
+            this.context.timelineRenderingType === TimelineRenderingType.Room ||
-            || this.context.timelineRenderingType === TimelineRenderingType.Search
+            this.context.timelineRenderingType === TimelineRenderingType.Pinned ||
-            || this.context.timelineRenderingType === TimelineRenderingType.Thread
+            this.context.timelineRenderingType === TimelineRenderingType.Search ||
-            || this.context.timelineRenderingType === TimelineRenderingType.ThreadsList;
+            this.context.timelineRenderingType === TimelineRenderingType.Thread ||
+            this.context.timelineRenderingType === TimelineRenderingType.ThreadsList
+        );
         if (!hasMessageActionBar) {
             return <MFileBody {...this.props} showGenericPlaceholder={false} />;
         }
@@ -525,7 +551,7 @@ export default class MImageBody extends React.Component<IBodyProps, IState> {
     render() {
         const content = this.props.mxEvent.getContent<IMediaEventContent>();
 
-        if (this.state.error !== null) {
+        if (this.state.error) {
             return (
                 <div className="mx_MImageBody">
                     <img src={require("../../../../res/img/warning.svg").default} width="16" height="16" />
@@ -534,12 +560,12 @@ export default class MImageBody extends React.Component<IBodyProps, IState> {
             );
         }
 
-        const contentUrl = this.getContentUrl();
+        const contentUrl = this.state.contentUrl;
-        let thumbUrl;
+        let thumbUrl: string;
-        if (this.props.forExport || (this.isGif() && SettingsStore.getValue("autoplayGifs"))) {
+        if (this.props.forExport || (this.state.isAnimated && SettingsStore.getValue("autoplayGifs"))) {
             thumbUrl = contentUrl;
         } else {
-            thumbUrl = this.getThumbUrl();
+            thumbUrl = this.state.thumbUrl ?? this.state.contentUrl;
         }
 
         const thumbnail = this.messageContent(contentUrl, thumbUrl, content);

src/components/views/messages/MImageReplyBody.tsx

@@ -41,14 +41,12 @@ export default class MImageReplyBody extends MImageBody {
     }
 
     render() {
-        if (this.state.error !== null) {
+        if (this.state.error) {
             return super.render();
         }
 
         const content = this.props.mxEvent.getContent<IMediaEventContent>();
-
+        const thumbnail = this.messageContent(this.state.contentUrl, this.state.thumbUrl, content, FORCED_IMAGE_HEIGHT);
-        const contentUrl = this.getContentUrl();
-        const thumbnail = this.messageContent(contentUrl, this.getThumbUrl(), content, FORCED_IMAGE_HEIGHT);
         const fileBody = this.getFileBody();
         const sender = <SenderProfile
             mxEvent={this.props.mxEvent}

src/utils/Image.ts

@@ -0,0 +1,76 @@
+/*
+ * 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.
+ */
+
+export function mayBeAnimated(mimeType: string): boolean {
+    return ["image/gif", "image/webp"].includes(mimeType);
+}
+
+function arrayBufferRead(arr: ArrayBuffer, start: number, len: number): Uint8Array {
+    return new Uint8Array(arr.slice(start, start + len));
+}
+
+function arrayBufferReadStr(arr: ArrayBuffer, start: number, len: number): string {
+    return String.fromCharCode.apply(null, arrayBufferRead(arr, start, len));
+}
+
+export async function blobIsAnimated(mimeType: string, blob: Blob): Promise<boolean> {
+    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, 17).arrayBuffer();
+        if (
+            arrayBufferReadStr(arr, 0, 4) === "RIFF" &&
+            arrayBufferReadStr(arr, 8, 4) === "WEBP" &&
+            arrayBufferReadStr(arr, 12, 4) === "VP8X"
+        ) {
+            const [flags] = arrayBufferRead(arr, 16, 1);
+            // Flags: R R I L E X _A_ R (reversed)
+            const animationFlagMask = 1 << 1;
+            return (flags & animationFlagMask) != 0;
+        }
+    } else if (mimeType === "image/gif") {
+        // Based on https://gist.github.com/zakirt/faa4a58cec5a7505b10e3686a226f285
+        // More info at http://www.matthewflickinger.com/lab/whatsinagif/bits_and_bytes.asp
+        const dv = new DataView(await blob.arrayBuffer(), 10);
+
+        const globalColorTable = dv.getUint8(0);
+        let globalColorTableSize = 0;
+        // check first bit, if 0, then we don't have a Global Color Table
+        if (globalColorTable & 0x80) {
+            // grab the last 3 bits, to calculate the global color table size -> RGB * 2^(N+1)
+            // N is the value in the last 3 bits.
+            globalColorTableSize = 3 * Math.pow(2, (globalColorTable & 0x7) + 1);
+        }
+
+        // move on to the Graphics Control Extension
+        const offset = 3 + globalColorTableSize;
+
+        const extensionIntroducer = dv.getUint8(offset);
+        const graphicsControlLabel = dv.getUint8(offset + 1);
+        let delayTime = 0;
+
+        // Graphics Control Extension section is where GIF animation data is stored
+        // First 2 bytes must be 0x21 and 0xF9
+        if ((extensionIntroducer & 0x21) && (graphicsControlLabel & 0xF9)) {
+            // skip to the 2 bytes with the delay time
+            delayTime = dv.getUint16(offset + 4);
+        }
+
+        return !!delayTime;
+    }
+
+    return false;
+}

src/utils/blobs.ts

@@ -52,6 +52,7 @@ const ALLOWED_BLOB_MIMETYPES = [
     'image/jpeg',
     'image/gif',
     'image/png',
+    'image/webp',
 
     'video/mp4',
     'video/webm',

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"