fix: audio attachments cannot be seeked using the progress slider

.changeset/lucky-donkeys-listen.md

@@ -0,0 +1,5 @@
+---
+'@rocket.chat/meteor': patch
+---
+
+Fixes audio attachments not being seekable using the progress slider

apps/meteor/server/lib/media/file-upload/config/FileSystem.ts

@@ -31,6 +31,7 @@ const FileSystemUploads = new FileUploadClass({
 			res.setHeader('Content-Disposition', `${getContentDisposition(req)}; filename*=UTF-8''${encodeURIComponent(file.name || '')}`);
 			file.uploadedAt && res.setHeader('Last-Modified', file.uploadedAt.toUTCString());
 			res.setHeader('Content-Type', file.type || 'application/octet-stream');
+			res.setHeader('Accept-Ranges', 'bytes');
 
 			if (req.headers.range) {
 				const range = getFileRange(file, req);

apps/meteor/server/lib/media/file-upload/config/GridFS.ts

@@ -71,6 +71,8 @@ const readFromGridFS = async function (
 	const rs = await store.getReadStream(fileId, file);
 	const ws = new stream.PassThrough();
 
+	res.setHeader('Accept-Ranges', 'bytes');
+
 	[rs, ws].forEach((stream) =>
 		stream.on('error', (err) => {
 			store.onReadError.call(store, err, fileId, file);

apps/meteor/server/lib/media/file-upload/lib/ranges.spec.ts

@@ -0,0 +1,63 @@
+import type http from 'node:http';
+
+import type { IUpload } from '@rocket.chat/core-typings';
+import { expect } from 'chai';
+import { describe, it } from 'mocha';
+
+import { getFileRange } from './ranges';
+
+const req = (range?: string) => ({ headers: { range } }) as http.IncomingMessage;
+const file = (size: number) => ({ size }) as IUpload;
+
+describe('getFileRange', () => {
+	it('returns undefined when no Range header is present', () => {
+		expect(getFileRange(file(1000), req())).to.equal(undefined);
+	});
+
+	it('returns undefined for a malformed Range header', () => {
+		expect(getFileRange(file(1000), req('bytes=abc'))).to.equal(undefined);
+		expect(getFileRange(file(1000), req('items=0-99'))).to.equal(undefined);
+		expect(getFileRange(file(1000), req('bytes=-'))).to.equal(undefined);
+	});
+
+	it('returns undefined when the file has no size', () => {
+		expect(getFileRange(file(0), req('bytes=0-'))).to.equal(undefined);
+	});
+
+	it('serves an open-ended range `bytes=0-` as the whole file', () => {
+		expect(getFileRange(file(1000), req('bytes=0-'))).to.deep.equal({ outOfRange: false, start: 0, stop: 999 });
+	});
+
+	it('serves an open-ended range from a mid-file offset to EOF', () => {
+		expect(getFileRange(file(1000), req('bytes=77-'))).to.deep.equal({ outOfRange: false, start: 77, stop: 999 });
+	});
+
+	it('serves an explicit closed range', () => {
+		expect(getFileRange(file(1000), req('bytes=100-199'))).to.deep.equal({ outOfRange: false, start: 100, stop: 199 });
+	});
+
+	it('clamps an end that runs past EOF', () => {
+		expect(getFileRange(file(1000), req('bytes=100-5000'))).to.deep.equal({ outOfRange: false, start: 100, stop: 999 });
+	});
+
+	it('serves a suffix range `bytes=-N` as the last N bytes', () => {
+		expect(getFileRange(file(1000), req('bytes=-200'))).to.deep.equal({ outOfRange: false, start: 800, stop: 999 });
+	});
+
+	it('clamps a suffix range larger than the file to the whole file', () => {
+		expect(getFileRange(file(1000), req('bytes=-5000'))).to.deep.equal({ outOfRange: false, start: 0, stop: 999 });
+	});
+
+	it('flags a start at or beyond EOF as out of range', () => {
+		expect(getFileRange(file(1000), req('bytes=1000-'))).to.deep.equal({ outOfRange: true, start: 1000, stop: 999 });
+		expect(getFileRange(file(1000), req('bytes=1500-1600'))).to.deep.equal({ outOfRange: true, start: 1500, stop: 999 });
+	});
+
+	it('flags an inverted closed range as out of range', () => {
+		expect(getFileRange(file(1000), req('bytes=200-100'))).to.deep.equal({ outOfRange: true, start: 200, stop: 100 });
+	});
+
+	it('serves the final byte of the file', () => {
+		expect(getFileRange(file(1000), req('bytes=999-'))).to.deep.equal({ outOfRange: false, start: 999, stop: 999 });
+	});
+});

apps/meteor/server/lib/media/file-upload/lib/ranges.ts

@@ -2,31 +2,54 @@ import type http from 'node:http';
 
 import type { IUpload } from '@rocket.chat/core-typings';
 
-function getByteRange(header?: string) {
+type ByteRange = { start?: number; stop?: number };
+
+function parseByteRange(header?: string): ByteRange | undefined {
 	if (!header) {
 		return;
 	}
-	const matches = header.match(/(\d+)-(\d+)/);
+	const matches = header.match(/^bytes=(\d*)-(\d*)$/);
 	if (!matches) {
 		return;
 	}
+	const [, startStr, stopStr] = matches;
+	if (startStr === '' && stopStr === '') {
+		return;
+	}
 	return {
-		start: parseInt(matches[1], 10),
-		stop: parseInt(matches[2], 10),
+		start: startStr === '' ? undefined : parseInt(startStr, 10),
+		stop: stopStr === '' ? undefined : parseInt(stopStr, 10),
 	};
 }
 
 export function getFileRange(file: IUpload, req: http.IncomingMessage) {
-	const range = getByteRange(req.headers.range);
-	if (!range) {
+	const parsed = parseByteRange(req.headers.range);
+	if (!parsed) {
 		return;
 	}
+
 	const size = file.size || 0;
-	if (range.start > size || range.stop <= range.start || range.stop > size) {
-		return { outOfRange: true, start: range.start, stop: range.stop };
+	if (size <= 0) {
+		return;
+	}
+
+	let { start, stop } = parsed;
+
+	if (start === undefined) {
+		if (!stop) {
+			return { outOfRange: true, start: 0, stop: size - 1 };
+		}
+		start = Math.max(0, size - stop);
+		stop = size - 1;
+	} else if (stop === undefined || stop > size - 1) {
+		stop = size - 1;
+	}
+
+	if (start > stop || start >= size) {
+		return { outOfRange: true, start, stop };
 	}
 
-	return { outOfRange: false, start: range.start, stop: range.stop };
+	return { outOfRange: false, start, stop };
 }
 
 // code from: https://github.com/jalik/jalik-ufs/blob/master/ufs-server.js#L310