feat: detect ArrayBuffer instance via isArrayBuffer()

Author: waitingsong

src/index.ts

@@ -2,4 +2,7 @@
 export * from './lib/index'
 export * from './lib/model'
 export { ErrorMsg } from './lib/config'
-export { validB64Chars } from './lib/helper'
+export {
+  isArrayBuffer,
+  validB64Chars,
+} from './lib/helper'

src/lib/browser.ts

@@ -3,6 +3,7 @@ import {
 } from './config'
 import { fromUint8Array } from './from_buffer'
 import {
+  isArrayBuffer,
   parseDecodeInputBase64,
   parseEncodeInputString,
   parseTextDecoder,
@@ -36,7 +37,7 @@ export function fromBuffer(buf: ArrayBuffer | Uint8Array): string {
   else if (ArrayBuffer.isView(buf)) {
     input = buf
   }
-  else if (buf instanceof ArrayBuffer) {
+  else if (isArrayBuffer(buf)) {
     input = new Uint8Array(buf)
   }
   else {

src/lib/helper.ts

@@ -77,3 +77,9 @@ export function isBrowser(): boolean {
     : true
   return ret
 }
+
+
+/** Whether input is instance of ArrayBuffer */
+export function isArrayBuffer(buffer: any): boolean {
+  return buffer && buffer instanceof ArrayBuffer ? true : false
+}

src/lib/nodejs.ts

@@ -1,6 +1,6 @@
 import { ErrorMsg } from './config'
 import {
-  parseDecodeInputBase64, parseEncodeInputString,
+  isArrayBuffer, parseDecodeInputBase64, parseEncodeInputString,
 } from './helper'
 
 
@@ -36,7 +36,7 @@ export function fromBuffer(buf: ArrayBuffer | Uint8Array): string {
   else if (ArrayBuffer.isView(buf)) {
     inst = Buffer.from(buf)
   }
-  else if (buf instanceof ArrayBuffer) {
+  else if (isArrayBuffer(buf)) {
     inst = Buffer.from(buf)
   }
   else {

test/30_helper.test.ts

@@ -13,14 +13,16 @@ import {
 
 import { ErrorMsg } from '../src/index'
 import {
+  isArrayBuffer,
+  isBrowser,
   parseDecodeInputBase64,
   parseEncodeInputString,
   parseTextDecoder,
   parseTextEncoder,
   validateEncoder,
 } from '../src/lib/helper'
 
-import { input9 } from './config'
+import { input44, input9, inputArrayBuffer, inputTypedArrayExcludingUint8Array, inputUint8Array } from './config'
 
 
 const filename = basename(__filename)
@@ -135,4 +137,26 @@ describe(filename, () => {
     })
   })
 
+
+  describe('isArrayBuffer() works', () => {
+    it('with valid input', () => {
+      inputArrayBuffer.forEach(value => {
+        const ret = isArrayBuffer(value)
+        assert(ret === true)
+      })
+    })
+
+    it('with invalid input', () => {
+      const arr = input44.concat(
+        inputTypedArrayExcludingUint8Array,
+        inputUint8Array,
+      )
+      arr.forEach(value => {
+        const ret = isArrayBuffer(value)
+        assert(ret === false)
+      })
+    })
+  })
+
+
 })

test/config.ts

@@ -119,3 +119,28 @@ export const input9 = [
   '*',
   '?',
 ]
+
+
+export const inputTypedArrayExcludingUint8Array = [
+  new Uint16Array(),
+  new Uint32Array(),
+  new Uint8ClampedArray(),
+  new Int8Array(),
+  new Int16Array(),
+  new Int32Array(),
+  new Float32Array(),
+  new Float64Array(),
+  new BigInt64Array(),
+]
+
+export const inputUint8Array = [
+  new Uint8Array(0),
+  new Uint8Array(1),
+  new Uint8Array(1024),
+]
+
+export const inputArrayBuffer = [
+  new ArrayBuffer(0),
+  new ArrayBuffer(1),
+  new ArrayBuffer(1024),
+]