fix the order of args in Decoder/Encoder

Author: gfx

README.md

@@ -50,7 +50,7 @@ deepStrictEqual(decode(encoded), object);
   - [`decodeArrayStream(stream: AsyncIterable<ArrayLike<number>> | ReadableStream<ArrayLike<number>>, options?: DecodeAsyncOptions): AsyncIterable<unknown>`](#decodearraystreamstream-asynciterablearraylikenumber--readablestreamarraylikenumber-options-decodeasyncoptions-asynciterableunknown)
   - [`decodeStream(stream: AsyncIterable<ArrayLike<number>> | ReadableStream<ArrayLike<number>>, options?: DecodeAsyncOptions): AsyncIterable<unknown>`](#decodestreamstream-asynciterablearraylikenumber--readablestreamarraylikenumber-options-decodeasyncoptions-asynciterableunknown)
   - [Extension Types](#extension-types)
-    - [Codec context](#codec-context)
+    - [ExtensionCodec context](#extensioncodec-context)
     - [Handling BigInt with ExtensionCodec](#handling-bigint-with-extensioncodec)
     - [The temporal module as timestamp extensions](#the-temporal-module-as-timestamp-extensions)
 - [Decoding a Blob](#decoding-a-blob)
@@ -266,7 +266,7 @@ const decoded = decode(encoded, { extensionCodec });
 
 Not that extension types for custom objects must be `[0, 127]`, while `[-1, -128]` is reserved for MessagePack itself.
 
-#### Codec context
+#### ExtensionCodec context
 
 When using an extension codec, it may be necessary to keep encoding/decoding state, to keep track of which objects got encoded/re-created. To do this, pass a `context` to the `EncodeOptions` and `DecodeOptions` (and if using typescript, type the `ExtensionCodec` too). Don't forget to pass the `{extensionCodec, context}` along recursive encoding/decoding:
 

benchmark/benchmark-from-msgpack-lite.ts

@@ -67,7 +67,7 @@ if (msgpack_msgpack) {
   const encoder = new msgpack_msgpack.Encoder();
   const decoder = new msgpack_msgpack.Decoder();
   buf = bench('buf = /* @msgpack/msgpack */ encoder.encode(obj);', (data) => encoder.encode(data), data);
-  obj = bench('obj = /* @msgpack/msgpack */ decoder.decodeSync(buf);', (buf) => decoder.decodeSync(buf), buf);
+  obj = bench('obj = /* @msgpack/msgpack */ decoder.decode(buf);', (buf) => decoder.decode(buf), buf);
   runTest(obj);
 
   if (process.env.CACHE_HIT_RATE) {

src/Decoder.ts

@@ -70,8 +70,8 @@ export class Decoder<ContextType> {
   private readonly stack: Array<StackState> = [];
 
   public constructor(
-    private readonly context: ContextType,
     private readonly extensionCodec: ExtensionCodecType<ContextType> = ExtensionCodec.defaultCodec as any,
+    private readonly context: ContextType = undefined as any,
     private readonly maxStrLength = DEFAULT_MAX_LENGTH,
     private readonly maxBinLength = DEFAULT_MAX_LENGTH,
     private readonly maxArrayLength = DEFAULT_MAX_LENGTH,

src/Encoder.ts

@@ -13,8 +13,8 @@ export class Encoder<ContextType> {
   private bytes = new Uint8Array(this.view.buffer);
 
   public constructor(
-    private readonly context: ContextType,
     private readonly extensionCodec: ExtensionCodecType<ContextType> = ExtensionCodec.defaultCodec as any,
+    private readonly context: ContextType = undefined as any,
     private readonly maxDepth = DEFAULT_MAX_DEPTH,
     private readonly initialBufferSize = DEFAULT_INITIAL_BUFFER_SIZE,
     private readonly sortKeys = false,

src/decode.ts

@@ -47,8 +47,8 @@ export function decode<ContextType>(
   options: DecodeOptions<SplitUndefined<ContextType>> = defaultDecodeOptions as any,
 ): unknown {
   const decoder = new Decoder<ContextType>(
-    (options as typeof options & { context: any }).context,
     options.extensionCodec,
+    (options as typeof options & { context: any }).context,
     options.maxStrLength,
     options.maxBinLength,
     options.maxArrayLength,

src/decodeAsync.ts

@@ -10,8 +10,8 @@ export async function decodeAsync<ContextType>(
   const stream = ensureAsyncIterabe(streamLike);
 
   const decoder = new Decoder<ContextType>(
-    (options as typeof options & { context: any }).context,
     options.extensionCodec,
+    (options as typeof options & { context: any }).context,
     options.maxStrLength,
     options.maxBinLength,
     options.maxArrayLength,
@@ -28,8 +28,8 @@ export function decodeArrayStream<ContextType>(
   const stream = ensureAsyncIterabe(streamLike);
 
   const decoder = new Decoder<ContextType>(
-    (options as typeof options & { context: any }).context,
     options.extensionCodec,
+    (options as typeof options & { context: any }).context,
     options.maxStrLength,
     options.maxBinLength,
     options.maxArrayLength,
@@ -47,8 +47,8 @@ export function decodeStream<ContextType>(
   const stream = ensureAsyncIterabe(streamLike);
 
   const decoder = new Decoder<ContextType>(
-    (options as typeof options & { context: any }).context,
     options.extensionCodec,
+    (options as typeof options & { context: any }).context,
     options.maxStrLength,
     options.maxBinLength,
     options.maxArrayLength,

src/encode.ts

@@ -40,8 +40,8 @@ export function encode<ContextType>(
   options: EncodeOptions<SplitUndefined<ContextType>> = defaultEncodeOptions as any,
 ): Uint8Array {
   const encoder = new Encoder<ContextType>(
-    (options as typeof options & { context: any }).context,
     options.extensionCodec,
+    (options as typeof options & { context: any }).context,
     options.maxDepth,
     options.initialBufferSize,
     options.sortKeys,

test/reuse-instances.test.ts

@@ -9,8 +9,8 @@ const createStream = async function* (...args: any) {
 
 describe("shared instances", () => {
   context("encode() and decodeSync()", () => {
-    const encoder = new Encoder(undefined);
-    const decoder = new Decoder(undefined);
+    const encoder = new Encoder();
+    const decoder = new Decoder();
 
     it("runs #1", () => {
       const object = {
@@ -46,8 +46,8 @@ describe("shared instances", () => {
   });
 
   context("encode() and decodeAsync()", () => {
-    const encoder = new Encoder(undefined);
-    const decoder = new Decoder(undefined);
+    const encoder = new Encoder();
+    const decoder = new Decoder();
 
     it("runs #1", async () => {
       const object = {
@@ -83,8 +83,8 @@ describe("shared instances", () => {
   });
 
   context("encode() and decodeStream()", () => {
-    const encoder = new Encoder(undefined);
-    const decoder = new Decoder(undefined);
+    const encoder = new Encoder();
+    const decoder = new Decoder();
 
     it("runs #1", async () => {
       const object = {
@@ -128,8 +128,8 @@ describe("shared instances", () => {
   });
 
   context("encode() and decodeArrayStream()", () => {
-    const encoder = new Encoder(undefined);
-    const decoder = new Decoder(undefined);
+    const encoder = new Encoder();
+    const decoder = new Decoder();
 
     it("runs #1", async () => {
       const object = {