chore: replace UTF-8 shims with native TextEncoder/TextDecoder

bilbospocketses · bilbospocketses · commit f9f06fc0fa91 · 2026-04-18T02:14:39.000-04:00
Util.stringToUtf8ByteArray and Util.utf8ByteArrayToString were
Google-Closure-derived (Apache 2.0, 2008) manual UTF-8 codecs — the file
even still carried the 'TODO(user): Use native implementations if/when
available' comment. Native TextEncoder and TextDecoder have been globals
in browsers and Node 14+ for years; they're behavior-equivalent for our
call sites and correct per WHATWG.

Replaced 20 call sites across 9 files: CommandControlMessage (SET_CLIPBOARD
+ PUSH_FILE encode/decode), FileListingClient, ListFilesModal, DeviceMessage
(clipboard + magic bytes), VideoSettings (codecOptions + encoderName),
multiplexer/Message (close reason), multiplexer/Multiplexer (text frame
data), server mw/FileListing (protocol command parsing),
server mw/WebsocketMultiplexer (channel code). Dropped the two functions
from Util.ts and removed now-unused 'import Util' from 5 files.

Net: -82 lines from Util.ts, +22/-29 across callers. 0 tsc errors,
89/89 tests pass, webpack clean.
diff --git a/src/app/Util.ts b/src/app/Util.ts
@@ -102,88 +102,6 @@ export default class Util {
     }
 
     // https://github.com/google/closure-library/blob/51e5a5ac373aefa354a991816ec418d730e29a7e/closure/goog/crypt/crypt.js#L117
-    /*
-    Copyright 2008 The Closure Library Authors. All Rights Reserved.
-    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.
- */
-    /* tslint:disable */
-    /**
-     * Converts a JS string to a UTF-8 "byte" array.
-     * @param {string} str 16-bit unicode string.
-     * @return {!Array<number>} UTF-8 byte array.
-     */
-    static stringToUtf8ByteArray = (str: string) => {
-        // TODO(user): Use native implementations if/when available
-        var out = [],
-            p = 0;
-        for (var i = 0; i < str.length; i++) {
-            var c = str.charCodeAt(i);
-            if (c < 128) {
-                out[p++] = c;
-            } else if (c < 2048) {
-                out[p++] = (c >> 6) | 192;
-                out[p++] = (c & 63) | 128;
-            } else if ((c & 0xfc00) == 0xd800 && i + 1 < str.length && (str.charCodeAt(i + 1) & 0xfc00) == 0xdc00) {
-                // Surrogate Pair
-                c = 0x10000 + ((c & 0x03ff) << 10) + (str.charCodeAt(++i) & 0x03ff);
-                out[p++] = (c >> 18) | 240;
-                out[p++] = ((c >> 12) & 63) | 128;
-                out[p++] = ((c >> 6) & 63) | 128;
-                out[p++] = (c & 63) | 128;
-            } else {
-                out[p++] = (c >> 12) | 224;
-                out[p++] = ((c >> 6) & 63) | 128;
-                out[p++] = (c & 63) | 128;
-            }
-        }
-        return Uint8Array.from(out);
-    };
-
-    /**
-     * Converts a UTF-8 byte array to JavaScript's 16-bit Unicode.
-     * @param {Uint8Array|Array<number>} bytes UTF-8 byte array.
-     * @return {string} 16-bit Unicode string.
-     */
-    static utf8ByteArrayToString(bytes: Uint8Array): string {
-        // TODO(user): Use native implementations if/when available
-        var out = [],
-            pos = 0,
-            c = 0;
-        while (pos < bytes.length) {
-            var c1 = bytes[pos++];
-            if (c1 < 128) {
-                out[c++] = String.fromCharCode(c1);
-            } else if (c1 > 191 && c1 < 224) {
-                var c2 = bytes[pos++];
-                out[c++] = String.fromCharCode(((c1 & 31) << 6) | (c2 & 63));
-            } else if (c1 > 239 && c1 < 365) {
-                // Surrogate Pair
-                var c2 = bytes[pos++];
-                var c3 = bytes[pos++];
-                var c4 = bytes[pos++];
-                var u = (((c1 & 7) << 18) | ((c2 & 63) << 12) | ((c3 & 63) << 6) | (c4 & 63)) - 0x10000;
-                out[c++] = String.fromCharCode(0xd800 + (u >> 10));
-                out[c++] = String.fromCharCode(0xdc00 + (u & 1023));
-            } else {
-                var c2 = bytes[pos++];
-                var c3 = bytes[pos++];
-                out[c++] = String.fromCharCode(((c1 & 15) << 12) | ((c2 & 63) << 6) | (c3 & 63));
-            }
-        }
-        return out.join('');
-    }
-    /* tslint:enable */
-
     // https://github.com/WICG/EventListenerOptions/blob/gh-pages/explainer.md
     static supportsPassive(): boolean {
         if (typeof Util.supportsPassiveValue === 'boolean') {
diff --git a/src/app/VideoSettings.ts b/src/app/VideoSettings.ts
@@ -2,7 +2,6 @@ import { BinaryReader } from './BinaryReader';
 import { BinaryWriter } from './BinaryWriter';
 import Rect from './Rect';
 import Size from './Size';
-import Util from './Util';
 
 interface Settings {
     crop?: Rect | null;
@@ -81,12 +80,12 @@ export default class VideoSettings {
         const codecOptionsLength = reader.readInt32BE();
         if (codecOptionsLength) {
             const codecOptionsBytes = reader.readBytes(codecOptionsLength);
-            codecOptions = Util.utf8ByteArrayToString(codecOptionsBytes);
+            codecOptions = new TextDecoder().decode(codecOptionsBytes);
         }
         const encoderNameLength = reader.readInt32BE();
         if (encoderNameLength) {
             const encoderNameBytes = reader.readBytes(encoderNameLength);
-            encoderName = Util.utf8ByteArrayToString(encoderNameBytes);
+            encoderName = new TextDecoder().decode(encoderNameBytes);
         }
         return new VideoSettings(
             {
@@ -145,11 +144,11 @@ export default class VideoSettings {
         let codecOptionsBytes;
         let encoderNameBytes;
         if (this.codecOptions) {
-            codecOptionsBytes = Util.stringToUtf8ByteArray(this.codecOptions);
+            codecOptionsBytes = new TextEncoder().encode(this.codecOptions);
             additionalLength += codecOptionsBytes.length;
         }
         if (this.encoderName) {
-            encoderNameBytes = Util.stringToUtf8ByteArray(this.encoderName);
+            encoderNameBytes = new TextEncoder().encode(this.encoderName);
             additionalLength += encoderNameBytes.length;
         }
         const writer = new BinaryWriter(VideoSettings.BASE_BUFFER_LENGTH + additionalLength);
diff --git a/src/app/controlMessage/CommandControlMessage.ts b/src/app/controlMessage/CommandControlMessage.ts
@@ -1,6 +1,5 @@
 import { BinaryReader } from '../BinaryReader';
 import { BinaryWriter } from '../BinaryWriter';
-import Util from '../Util';
 import type VideoSettings from '../VideoSettings';
 import { ControlMessage } from './ControlMessage';
 
@@ -58,7 +57,7 @@ export class CommandControlMessage extends ControlMessage {
 
     public static createSetClipboardCommand(text: string, paste = false, sequence = 0n): CommandControlMessage {
         const event = new CommandControlMessage(ControlMessage.TYPE_SET_CLIPBOARD);
-        const textBytes: Uint8Array | null = text ? Util.stringToUtf8ByteArray(text) : null;
+        const textBytes: Uint8Array | null = text ? new TextEncoder().encode(text) : null;
         const textLength = textBytes ? textBytes.length : 0;
         // type(1) + sequence(8) + paste(1) + textLength(4) + text
         const writer = new BinaryWriter(1 + 8 + 1 + 4 + textLength)
@@ -103,7 +102,7 @@ export class CommandControlMessage extends ControlMessage {
 
     private static createPushFileStartCommand(id: number, fileName: string, fileSize: number): CommandControlMessage {
         const event = new CommandControlMessage(ControlMessage.TYPE_PUSH_FILE);
-        const text = Util.stringToUtf8ByteArray(fileName);
+        const text = new TextEncoder().encode(fileName);
         const typeField = 1;
         const idField = 2;
         const stateField = 1;
@@ -185,7 +184,7 @@ export class CommandControlMessage extends ControlMessage {
         } else if (state === FilePushState.START) {
             fileSize = reader.readUInt32BE();
             const textLength = reader.readUInt16BE();
-            fileName = Util.utf8ByteArrayToString(reader.readBytes(textLength));
+            fileName = new TextDecoder().decode(reader.readBytes(textLength));
         }
         return { id, state, chunk, fileName, fileSize };
     }
diff --git a/src/app/googDevice/DeviceMessage.ts b/src/app/googDevice/DeviceMessage.ts
@@ -1,13 +1,12 @@
 import { BinaryReader } from '../BinaryReader';
-import Util from '../Util';
 
 export default class DeviceMessage {
     public static TYPE_CLIPBOARD = 0;
     public static TYPE_ACK_CLIPBOARD = 1;
     public static TYPE_UHID_OUTPUT = 2;
     public static TYPE_PUSH_RESPONSE = 101; // custom, not used with vanilla scrcpy v3.x
 
-    public static readonly MAGIC_BYTES_MESSAGE = Util.stringToUtf8ByteArray('scrcpy_message');
+    public static readonly MAGIC_BYTES_MESSAGE = new TextEncoder().encode('scrcpy_message');
 
     constructor(
         public readonly type: number,
@@ -36,7 +35,7 @@ export default class DeviceMessage {
         const reader = new BinaryReader(this.data, 1);
         const length = reader.readInt32BE();
         const textBytes = reader.readBytes(length);
-        return Util.utf8ByteArrayToString(textBytes);
+        return new TextDecoder().decode(textBytes);
     }
 
     public getAckSequence(): bigint {
diff --git a/src/app/googDevice/client/FileListingClient.ts b/src/app/googDevice/client/FileListingClient.ts
@@ -393,7 +393,7 @@ export class FileListingClient extends ManagerClient<ParamsFileListing, never> i
                 const size = statView.getUint32(4, true);
                 const mtime = statView.getUint32(8, true);
                 const namelen = statView.getUint32(12, true);
-                const name = Util.utf8ByteArrayToString(stat.subarray(16, 16 + namelen));
+                const name = new TextDecoder().decode(stat.subarray(16, 16 + namelen));
                 this.addEntry(new Entry(name, mode, size, mtime));
                 return;
             }
@@ -432,7 +432,7 @@ export class FileListingClient extends ManagerClient<ParamsFileListing, never> i
             case Protocol.FAIL: {
                 const dataView = new DataView(data.buffer, data.byteOffset);
                 const length = dataView.getUint32(4, true);
-                const message = Util.utf8ByteArrayToString(data.subarray(8, 8 + length));
+                const message = new TextDecoder().decode(data.subarray(8, 8 + length));
                 console.error(TAG, `FAIL: ${message}`);
                 return;
             }
@@ -592,7 +592,7 @@ export class FileListingClient extends ManagerClient<ParamsFileListing, never> i
     }
 
     protected getChannelInitData(): Uint8Array {
-        const serial = Util.stringToUtf8ByteArray(this.serial);
+        const serial = new TextEncoder().encode(this.serial);
         return new BinaryWriter(4 + 4 + serial.byteLength)
             .writeString(ChannelCode.FSLS)
             .writeUInt32LE(serial.length)
diff --git a/src/app/googDevice/client/ListFilesModal.ts b/src/app/googDevice/client/ListFilesModal.ts
@@ -5,7 +5,6 @@ import { ChannelCode } from '../../../common/ChannelCode';
 import { Multiplexer } from '../../../packages/multiplexer/Multiplexer';
 import { BinaryWriter } from '../../BinaryWriter';
 import { Modal } from '../../ui/Modal';
-import Util from '../../Util';
 import { Entry } from '../Entry';
 import { createFileIconForEntry } from './FileIconUtils';
 import { AdbkitFilePushStream } from '../filePush/AdbkitFilePushStream';
@@ -506,7 +505,7 @@ export class ListFilesModal extends Modal implements DragAndPushListener {
     // ── Directory listing protocol ──
 
     private getChannelInitData(): Uint8Array {
-        const serial = Util.stringToUtf8ByteArray(this.udid);
+        const serial = new TextEncoder().encode(this.udid);
         return new BinaryWriter(4 + 4 + serial.byteLength)
             .writeString(ChannelCode.FSLS)
             .writeUInt32LE(serial.length)
@@ -619,7 +618,7 @@ export class ListFilesModal extends Modal implements DragAndPushListener {
                 const size = statView.getUint32(4, true);
                 const mtime = statView.getUint32(8, true);
                 const namelen = statView.getUint32(12, true);
-                const name = Util.utf8ByteArrayToString(stat.subarray(16, 16 + namelen));
+                const name = new TextDecoder().decode(stat.subarray(16, 16 + namelen));
                 const entry = new Entry(name, mode, size, mtime);
                 // Skip '.' and '..'
                 if (name !== '.' && name !== '..') {
@@ -682,7 +681,7 @@ export class ListFilesModal extends Modal implements DragAndPushListener {
             case Protocol.FAIL: {
                 const dataView = new DataView(data.buffer, data.byteOffset);
                 const length = dataView.getUint32(4, true);
-                const message = Util.utf8ByteArrayToString(data.subarray(8, 8 + length));
+                const message = new TextDecoder().decode(data.subarray(8, 8 + length));
                 console.error(TAG, `FAIL: ${message}`);
                 return;
             }
diff --git a/src/packages/multiplexer/Message.ts b/src/packages/multiplexer/Message.ts
@@ -1,4 +1,3 @@
-import Util from '../../app/Util';
 import { CloseEventClass } from './CloseEventClass';
 import { MessageType } from './MessageType';
 
@@ -14,7 +13,7 @@ export class Message {
     }
 
     public static fromCloseEvent(id: number, code: number, reason?: string): Message {
-        const reasonBytes = reason ? Util.stringToUtf8ByteArray(reason) : new Uint8Array(0);
+        const reasonBytes = reason ? new TextEncoder().encode(reason) : new Uint8Array(0);
         const buf = new Uint8Array(2 + 4 + reasonBytes.byteLength);
         const view = new DataView(buf.buffer);
         view.setUint16(0, code, true);
@@ -54,7 +53,7 @@ export class Message {
             code = view.getUint16(0, true);
             if (this.data.byteLength > 6) {
                 const length = view.getUint32(2, true);
-                reason = Util.utf8ByteArrayToString(new Uint8Array(this.data, 6, length));
+                reason = new TextDecoder().decode(new Uint8Array(this.data, 6, length));
             }
         }
         return new CloseEventClass('close', {
diff --git a/src/packages/multiplexer/Multiplexer.ts b/src/packages/multiplexer/Multiplexer.ts
@@ -101,7 +101,7 @@ export class Multiplexer extends TypedEmitter<MultiplexerEvents> implements WebS
                     if (data) {
                         const { channel } = data;
                         const msg = new MessageEventClass('message', {
-                            data: Util.utf8ByteArrayToString(new Uint8Array(message.data)),
+                            data: new TextDecoder().decode(new Uint8Array(message.data)),
                             lastEventId: event.lastEventId,
                             origin: event.origin,
                             source: event.source,
diff --git a/src/server/goog-device/mw/FileListing.ts b/src/server/goog-device/mw/FileListing.ts
@@ -1,4 +1,3 @@
-import Util from '../../../app/Util';
 import Protocol from '../../../common/AdbProtocol';
 import { ChannelCode } from '../../../common/ChannelCode';
 import type { Multiplexer } from '../../../packages/multiplexer/Multiplexer';
@@ -23,7 +22,7 @@ export class FileListing extends Mw {
         }
         const buffer = Buffer.from(data);
         const length = buffer.readInt32LE(0);
-        const serial = Util.utf8ByteArrayToString(buffer.slice(4, 4 + length));
+        const serial = new TextDecoder().decode(buffer.slice(4, 4 + length));
         FileListing.log.info(`processChannel: accepted for serial="${serial}"`);
         return new FileListing(ws, serial);
     }
@@ -53,7 +52,7 @@ export class FileListing extends Mw {
             return;
         }
         let offset = 0;
-        const cmd = Util.utf8ByteArrayToString(data.slice(offset, 4));
+        const cmd = new TextDecoder().decode(data.slice(offset, 4));
         offset += 4;
         switch (cmd) {
             case Protocol.LIST:
@@ -62,7 +61,7 @@ export class FileListing extends Mw {
                 const length = data.readUInt32LE(offset);
                 offset += 4;
                 const pathBuffer = data.slice(offset, offset + length);
-                const pathString = Util.utf8ByteArrayToString(pathBuffer);
+                const pathString = new TextDecoder().decode(pathBuffer);
                 FileListing.handle(cmd, serial, pathString, channel).catch((error: Error) => {
                     FileListing.log.error(error.message);
                 });
diff --git a/src/server/mw/WebsocketMultiplexer.ts b/src/server/mw/WebsocketMultiplexer.ts
@@ -1,5 +1,4 @@
 import type WS from 'ws';
-import Util from '../../app/Util';
 import { ACTION } from '../../common/Action';
 import { Multiplexer } from '../../packages/multiplexer/Multiplexer';
 import { Logger } from '../Logger';
@@ -51,7 +50,7 @@ export class WebsocketMultiplexer extends Mw {
         let processed = false;
         for (const mwFactory of WebsocketMultiplexer.mwFactories.values()) {
             try {
-                const code = Util.utf8ByteArrayToString(Buffer.from(data).slice(0, 4));
+                const code = new TextDecoder().decode(Buffer.from(data).slice(0, 4));
                 const buffer = data.byteLength > 4 ? data.slice(4) : undefined;
                 const mw = mwFactory.processChannel(channel, code, buffer);
                 if (mw) {

Original file line number	Diff line number	Diff line change
`@@ -1,4 +1,3 @@`
`1`		`-import Util from '../../app/Util';`
`2`	`1`	`import { CloseEventClass } from './CloseEventClass';`
`3`	`2`	`import { MessageType } from './MessageType';`
`4`	`3`
`@@ -14,7 +13,7 @@ export class Message {`
`14`	`13`	`}`
`15`	`14`
`16`	`15`	`public static fromCloseEvent(id: number, code: number, reason?: string): Message {`
`17`		`- const reasonBytes = reason ? Util.stringToUtf8ByteArray(reason) : new Uint8Array(0);`
	`16`	`+ const reasonBytes = reason ? new TextEncoder().encode(reason) : new Uint8Array(0);`
`18`	`17`	`const buf = new Uint8Array(2 + 4 + reasonBytes.byteLength);`
`19`	`18`	`const view = new DataView(buf.buffer);`
`20`	`19`	`view.setUint16(0, code, true);`
`@@ -54,7 +53,7 @@ export class Message {`
`54`	`53`	`code = view.getUint16(0, true);`
`55`	`54`	`if (this.data.byteLength > 6) {`
`56`	`55`	`const length = view.getUint32(2, true);`
`57`		`- reason = Util.utf8ByteArrayToString(new Uint8Array(this.data, 6, length));`
	`56`	`+ reason = new TextDecoder().decode(new Uint8Array(this.data, 6, length));`
`58`	`57`	`}`
`59`	`58`	`}`
`60`	`59`	`return new CloseEventClass('close', {`