Reader from

index.d.ts

@@ -3,6 +3,8 @@ import JSBI from "jsbi";
 export class Reader {
   constructor(reader: string | ArrayBuffer | Reader);
   static fromRawString(s: string): Reader;
+  static isReader(x: unknown): x is Reader;
+  static from(x: string | ArrayBuffer | Reader | Uint8Array): Reader;
 
   length(): number;
   indexAt(i: number): number;

src/reader.js

@@ -1,5 +1,29 @@
-class ArrayBufferReader {
+class BaseReader {
+  constructor() {
+    /**
+     * instanceof would be nice here, but when a user use multi version of Reader that may cause problem
+     * @example
+     * const { Reader } = require('ckb-js-toolkit'); // [email protected]
+     * const { readSomething } = require('other-serializer-lib'); // dependent on [email protected]
+     *
+     * readSomething() instanceof Reader; // false
+     *
+     * @type {boolean}
+     * @protected
+     */
+    this.__isByteLikeReader__ = true;
+  }
+
+  static isReader(x) {
+    if (x == null) return false;
+    if (x instanceof BaseReader) return true;
+    return x.__isByteLikeReader__ === true;
+  }
+}
+
+class ArrayBufferReader extends BaseReader {
   constructor(buffer) {
+    super();
     this.view = new DataView(buffer);
   }
 
@@ -27,8 +51,9 @@ class ArrayBufferReader {
   }
 }
 
-class HexStringReader {
+class HexStringReader extends BaseReader {
   constructor(string) {
+    super();
     this.string = string;
   }
 
@@ -55,16 +80,17 @@ class HexStringReader {
   }
 }
 
-export class Reader {
+export class Reader extends BaseReader {
   constructor(input) {
+    super();
     if (
       input instanceof HexStringReader ||
       input instanceof ArrayBufferReader
     ) {
       return input;
     }
     if (typeof input === "string") {
-      if (!input.startsWith("0x") || input.length % 2 != 0) {
+      if (!input.startsWith("0x") || input.length % 2 !== 0) {
         throw new Error(
           "Hex string must start with 0x, and has even numbered length!"
         );
@@ -74,9 +100,17 @@ export class Reader {
     if (input instanceof ArrayBuffer) {
       return new ArrayBufferReader(input);
     }
+
+    if (input instanceof Uint8Array) {
+      return new ArrayBufferReader(Uint8Array.from(input).buffer);
+    }
     throw new Error("Reader can only accept hex string or ArrayBuffer!");
   }
 
+  static from(x) {
+    return new Reader(x);
+  }
+
   static fromRawString(string) {
     const buffer = new ArrayBuffer(string.length);
     const view = new DataView(buffer);

tests/reader.js

@@ -0,0 +1,19 @@
+const test = require("ava");
+const { Reader } = require("../build/ckb-js-toolkit.node");
+
+test("reader functions", t => {
+  const ra = Reader.from("0x12345678");
+  const rb = Reader.from(Uint8Array.from([0x12, 0x34, 0x56, 0x78]));
+  const rc = Reader.from(Buffer.from("12345678", "hex"));
+  const rd = Reader.from(Uint8Array.from([0x12, 0x34, 0x56, 0x78]).buffer);
+
+  t.is(new DataView(ra.toArrayBuffer()).getUint32(0), 0x12345678);
+  t.is(new DataView(rb.toArrayBuffer()).getUint32(0), 0x12345678);
+  t.is(new DataView(rc.toArrayBuffer()).getUint32(0), 0x12345678);
+  t.is(new DataView(rd.toArrayBuffer()).getUint32(0), 0x12345678);
+
+  t.true(Reader.isReader(ra));
+  t.true(Reader.isReader(rb));
+  t.true(Reader.isReader(rc));
+  t.true(Reader.isReader(rd));
+});