refactor: simplify Uint8Array checks

Author: ChALkeR

base58.js

@@ -1,6 +1,5 @@
 import { typedView } from './array.js'
-import { assertUint8 } from './assert.js'
-import { E_STRING } from './fallback/_utils.js'
+import { assertU8, E_STRING } from './fallback/_utils.js'
 import { nativeDecoder, nativeEncoder, isHermes } from './fallback/platform.js'
 import { encodeAscii, decodeAscii } from './fallback/latin1.js'
 
@@ -24,7 +23,7 @@ const E_CHAR = 'Invalid character in base58 input'
 const shouldUseBigIntFrom = isHermes // faster only on Hermes, numbers path beats it on normal engines
 
 function toBase58core(arr, alphabet, codes) {
-  assertUint8(arr)
+  assertU8(arr)
   const length = arr.length
   if (length === 0) return ''
 

fallback/_utils.js

@@ -6,6 +6,10 @@ export function assert(condition, msg) {
   if (!condition) throw new Error(msg)
 }
 
+export function assertU8(arg) {
+  if (!(arg instanceof Uint8Array)) throw new TypeError('Expected an Uint8Array')
+}
+
 // On arrays in heap (<= 64) it's cheaper to copy into a pooled buffer than lazy-create the ArrayBuffer storage
 export const toBuf = (x) =>
   x.byteLength <= 64 && x.BYTES_PER_ELEMENT === 1

fallback/hex.js

@@ -1,4 +1,3 @@
-import { assertUint8 } from '../assert.js'
 import { E_STRING } from './_utils.js'
 import { nativeDecoder, nativeEncoder, decode2string } from './platform.js'
 import { encodeAscii, decodeAscii } from './latin1.js'
@@ -12,9 +11,8 @@ const allowed = '0123456789ABCDEFabcdef'
 
 export const E_HEX = 'Input is not a hex string'
 
+// Expects a checked Uint8Array
 export function toHex(arr) {
-  assertUint8(arr)
-
   if (!hexArray) hexArray = Array.from({ length: 256 }, (_, i) => i.toString(16).padStart(2, '0'))
   const length = arr.length // this helps Hermes
 

hex.js

@@ -1,11 +1,11 @@
-import { assertUint8 } from './assert.js'
 import { typedView } from './array.js'
+import { assertU8 } from './fallback/_utils.js'
 import * as js from './fallback/hex.js'
 
 const { toHex: webHex } = Uint8Array.prototype // Modern engines have this
 
 export function toHex(arr) {
-  assertUint8(arr)
+  assertU8(arr)
   if (arr.length === 0) return ''
   if (webHex && arr.toHex === webHex) return arr.toHex()
   return js.toHex(arr)