refactor: use native btoa supported on RN 0.74+

Author: dcangulo

package.json

@@ -64,7 +64,6 @@
   },
   "homepage": "https://github.com/dcangulo/react-native-pkce-challenge#readme",
   "dependencies": {
-    "base-64": "^1.0.0",
     "js-sha256": "^0.11.0"
   },
   "devDependencies": {

src/utils.ts

@@ -1,5 +1,4 @@
 import { sha256 } from 'js-sha256';
-import base64 from 'base-64';
 
 const BYTE_LENGTH = 96;
 
@@ -14,7 +13,7 @@ export function base64UrlEncode(str: string) {
 
 export function generateChallenge(verifier: string) {
   const digest = sha256.digest(verifier);
-  const hash = base64.encode(String.fromCharCode(...new Uint8Array(digest)));
+  const hash = btoa(String.fromCharCode(...new Uint8Array(digest)));
 
   return base64UrlEncode(hash);
 }
@@ -29,7 +28,7 @@ export function getRandomBase64StringFallback(byteLength: number) {
   console.warn('Native getRandomValues function not found. Falling back to insecure Math.random.');
 
   const buffer = new Uint8Array(byteLength).map(() => Math.floor(Math.random() * 256));
-  const bytes = base64.encode(String.fromCharCode(...new Uint8Array(buffer)));
+  const bytes = btoa(String.fromCharCode(...new Uint8Array(buffer)));
 
   return bytes;
 }

yarn.lock

@@ -4099,13 +4099,6 @@ __metadata:
   languageName: node
   linkType: hard
 
-"base-64@npm:^1.0.0":
-  version: 1.0.0
-  resolution: "base-64@npm:1.0.0"
-  checksum: d10b64a1fc9b2c5a5f39f1ce1e6c9d1c5b249222bbfa3a0604c592d90623caf74419983feadd8a170f27dc0c3389704f72faafa3e645aeb56bfc030c93ff074a
-  languageName: node
-  linkType: hard
-
 "base64-js@npm:^1.3.1, base64-js@npm:^1.5.1":
   version: 1.5.1
   resolution: "base64-js@npm:1.5.1"
@@ -9730,7 +9723,6 @@ __metadata:
     "@react-native/eslint-config": ^0.73.1
     "@types/base-64": ^1.0.2
     "@types/react": ^18.2.44
-    base-64: ^1.0.0
     commitlint: ^17.0.2
     del-cli: ^5.1.0
     eslint: ^8.51.0