From 4746c3d71e788670898bad81faf8cfb664c29645 Mon Sep 17 00:00:00 2001
From: Josh Kelley <joshkel@gmail.com>
Date: Mon, 4 Aug 2025 11:18:52 -0400
Subject: [PATCH] More specific data types - ArrayBuffer instead of
 ArrayBufferLike

By default, TypeScript interfaces like `DataView` and `Uint8Array` are used with the more generic `ArrayBufferLike` type, representing that they can work with either `ArrayBuffer` or `SharedArrayBuffer`. TypeScript 5.9 now uses stricter types for interfaces such as the DOM `fetch` method: a DOM `BufferSource` is now (correctly) marked as requiring `ArrayBuffer`, not `SharedArrayBuffer`.  As a result of that change, trying to use a @msgpack/msgpack `encode` result with a `fetch` call will result in a type error. This change updates the types in the `Encoder` class to use `ArrayBuffer` instead of `ArrayBufferLike`, which reflects their implementation and prevents issues with the newer, stricter interfaces.
---
 src/Encoder.ts | 8 ++++----
 src/encode.ts  | 2 +-
 2 files changed, 5 insertions(+), 5 deletions(-)

diff --git a/src/Encoder.ts b/src/Encoder.ts
index 43fcd8f..b047c1d 100644
--- a/src/Encoder.ts
+++ b/src/Encoder.ts
@@ -84,8 +84,8 @@ export class Encoder<ContextType = undefined> {
   private readonly forceIntegerToFloat: boolean;
 
   private pos: number;
-  private view: DataView;
-  private bytes: Uint8Array;
+  private view: DataView<ArrayBuffer>;
+  private bytes: Uint8Array<ArrayBuffer>;
 
   private entered = false;
 
@@ -132,7 +132,7 @@ export class Encoder<ContextType = undefined> {
    *
    * @returns Encodes the object and returns a shared reference the encoder's internal buffer.
    */
-  public encodeSharedRef(object: unknown): Uint8Array {
+  public encodeSharedRef(object: unknown): Uint8Array<ArrayBuffer> {
     if (this.entered) {
       const instance = this.clone();
       return instance.encodeSharedRef(object);
@@ -152,7 +152,7 @@ export class Encoder<ContextType = undefined> {
   /**
    * @returns Encodes the object and returns a copy of the encoder's internal buffer.
    */
-  public encode(object: unknown): Uint8Array {
+  public encode(object: unknown): Uint8Array<ArrayBuffer> {
     if (this.entered) {
       const instance = this.clone();
       return instance.encode(object);
diff --git a/src/encode.ts b/src/encode.ts
index 9a9d07a..194b67a 100644
--- a/src/encode.ts
+++ b/src/encode.ts
@@ -11,7 +11,7 @@ import type { SplitUndefined } from "./context.ts";
 export function encode<ContextType = undefined>(
   value: unknown,
   options?: EncoderOptions<SplitUndefined<ContextType>>,
-): Uint8Array {
+): Uint8Array<ArrayBuffer> {
   const encoder = new Encoder(options);
   return encoder.encodeSharedRef(value);
 }