feature: decode ArrayBuffer as well as byte arrays

gfx · gfx · commit a22691f76419 · 2019-07-16T23:36:47.000+09:00
diff --git a/README.md b/README.md
@@ -44,7 +44,7 @@ deepStrictEqual(decode(encoded), object);
 - [API](#api)
   - [`encode(data: unknown, options?: EncodeOptions): Uint8Array`](#encodedata-unknown-options-encodeoptions-uint8array)
     - [`EncodeOptions`](#encodeoptions)
-  - [`decode(buffer: ArrayLike<number>, options?: DecodeOptions): unknown`](#decodebuffer-arraylikenumber-options-decodeoptions-unknown)
+  - [`decode(buffer: ArrayLike<number> | ArrayBuffer, options?: DecodeOptions): unknown`](#decodebuffer-arraylikenumber--arraybuffer-options-decodeoptions-unknown)
     - [`DecodeOptions`](#decodeoptions)
   - [`decodeAsync(stream: AsyncIterable<ArrayLike<number>> | ReadableStream<ArrayLike<number>>, options?: DecodeAsyncOptions): Promise<unknown>`](#decodeasyncstream-asynciterablearraylikenumber--readablestreamarraylikenumber-options-decodeasyncoptions-promiseunknown)
   - [`decodeArrayStream(stream: AsyncIterable<ArrayLike<number>> | ReadableStream<ArrayLike<number>>, options?: DecodeAsyncOptions): AsyncIterable<unknown>`](#decodearraystreamstream-asynciterablearraylikenumber--readablestreamarraylikenumber-options-decodeasyncoptions-asynciterableunknown)
@@ -115,11 +115,11 @@ maxDepth | number | `100`
 initialBufferSize | number | `2048`
 sortKeys | boolean | false
 
-### `decode(buffer: ArrayLike<number>, options?: DecodeOptions): unknown`
+### `decode(buffer: ArrayLike<number> | ArrayBuffer, options?: DecodeOptions): unknown`
 
 It decodes `buffer` encoded as MessagePack, and returns a decoded object as `uknown`.
 
-`buffer` must be an array of bytes, which is typically `Uint8Array`.
+`buffer` must be an array of bytes, which is typically `Uint8Array`, or `ArrayBuffer`.
 
 for example:
 
diff --git a/src/Decoder.ts b/src/Decoder.ts
@@ -68,7 +68,7 @@ export class Decoder {
     readonly maxExtLength = DEFAULT_MAX_LENGTH,
   ) {}
 
-  setBuffer(buffer: ArrayLike<number>): void {
+  setBuffer(buffer: ArrayLike<number> | ArrayBuffer): void {
     this.bytes = ensureUint8Array(buffer);
     this.view = createDataView(this.bytes);
     this.pos = 0;
diff --git a/src/decode.ts b/src/decode.ts
@@ -35,7 +35,10 @@ export type DecodeOptions = Partial<
 
 export const defaultDecodeOptions: DecodeOptions = {};
 
-export function decode(buffer: ArrayLike<number>, options: DecodeOptions = defaultDecodeOptions): unknown {
+export function decode(
+  buffer: ArrayLike<number> | ArrayBuffer,
+  options: DecodeOptions = defaultDecodeOptions,
+): unknown {
   const decoder = new Decoder(
     options.extensionCodec,
     options.maxStrLength,
diff --git a/src/utils/typedArrays.ts b/src/utils/typedArrays.ts
@@ -1,8 +1,10 @@
-export function ensureUint8Array(buffer: ArrayLike<number> | Uint8Array | ArrayBufferView) {
+export function ensureUint8Array(buffer: ArrayLike<number> | Uint8Array | ArrayBufferView | ArrayBuffer) {
   if (buffer instanceof Uint8Array) {
     return buffer;
   } else if (ArrayBuffer.isView(buffer)) {
     return new Uint8Array(buffer.buffer, buffer.byteOffset, buffer.byteLength);
+  } else if (buffer instanceof ArrayBuffer) {
+    return new Uint8Array(buffer);
   } else {
     // ArrayLike<number>
     return Uint8Array.from(buffer);
diff --git a/test/encode-options.test.ts b/test/encode-options.test.ts
diff --git a/test/encode.test.ts b/test/encode.test.ts
@@ -0,0 +1,16 @@
+import assert from "assert";
+import { encode, decode } from "@msgpack/msgpack";
+
+describe("encode", () => {
+  context("sortKeys", () => {
+    it("canonicalize encoded binaries", () => {
+      assert.deepStrictEqual(encode({ a: 1, b: 2 }, { sortKeys: true }), encode({ b: 2, a: 1 }, { sortKeys: true }));
+    });
+  });
+
+  context("ArrayBuffer as buffer", () => {
+    const buffer = encode([1, 2, 3]);
+    const arrayBuffer = buffer.buffer.slice(buffer.byteOffset, buffer.byteLength);
+    assert.deepStrictEqual(decode(arrayBuffer), decode(buffer));
+  });
+});
