fix(NODE-5363): defer byte slicing to utf8 decoding API in nodejs

src/binary.ts

@@ -223,8 +223,8 @@ export class Binary extends BSONValue {
   toString(encoding?: 'hex' | 'base64' | 'utf8' | 'utf-8'): string {
     if (encoding === 'hex') return ByteUtils.toHex(this.buffer);
     if (encoding === 'base64') return ByteUtils.toBase64(this.buffer);
-    if (encoding === 'utf8' || encoding === 'utf-8') return ByteUtils.toUTF8(this.buffer);
-    return ByteUtils.toUTF8(this.buffer);
+    if (encoding === 'utf8' || encoding === 'utf-8') return ByteUtils.toUTF8(this.buffer, 0, this.buffer.length);
+    return ByteUtils.toUTF8(this.buffer, 0, this.buffer.length);
   }
 
   /** @internal */

src/utils/byte_utils.ts

@@ -26,7 +26,7 @@ export type ByteUtils = {
   /** Create a Uint8Array containing utf8 code units from a string */
   fromUTF8: (text: string) => Uint8Array;
   /** Create a string from utf8 code units */
-  toUTF8: (buffer: Uint8Array, start?: number, end?: number) => string;
+  toUTF8: (buffer: Uint8Array, start: number, end: number) => string;
   /** Get the utf8 code unit count from a string if it were to be transformed to utf8 */
   utf8ByteLength: (input: string) => number;
   /** Encode UTF8 bytes generated from `source` string into `destination` at byteOffset. Returns the number of bytes encoded. */

src/utils/web_byte_utils.ts

@@ -172,7 +172,7 @@ export const webByteUtils = {
     return new TextEncoder().encode(text);
   },
 
-  toUTF8(uint8array: Uint8Array, start?: number, end?: number): string {
+  toUTF8(uint8array: Uint8Array, start: number, end: number): string {
     return new TextDecoder('utf8', { fatal: false }).decode(uint8array.slice(start, end));
   },