feat: add package for performant base64 encoding

Author: EscapedGibbon

package.json

@@ -43,6 +43,7 @@
   },
   "homepage": "https://github.com/image-js/image-js#readme",
   "dependencies": {
+    "@jsonjoy.com/base64": "^1.1.2",
     "bresenham-zingl": "^0.2.0",
     "colord": "^2.9.3",
     "fast-bmp": "^2.0.1",

src/save/__tests__/encodeBase64.test.ts

@@ -2,6 +2,9 @@ import { createRgbaImage } from '../../../test/testUtils.js';
 import { encode } from '../encode.js';
 import { encodeBase64 } from '../encodeBase64.js';
 
+/**
+ * @vitest-environment jsdom
+ */
 test('basic image (png)', () => {
   const image = testUtils.createGreyImage([
     [0, 0, 0, 0, 0],

src/save/encodeBase64.ts

@@ -1,8 +1,9 @@
+import { toBase64 } from '@jsonjoy.com/base64';
+
 import type { Image } from '../Image.js';
 
 import { encode } from './encode.js';
 import type { ImageFormat } from './encode.js';
-
 /**
  * Converts image into a base64 URL string.
  * @param image - Image to get base64 encoding from.
@@ -11,12 +12,7 @@ import type { ImageFormat } from './encode.js';
  */
 export function encodeBase64(image: Image, format: ImageFormat) {
   const buffer = encode(image, { format });
-  const binaryArray = [];
-  for (const el of buffer) {
-    binaryArray.push(String.fromCodePoint(el));
-  }
-  const binaryString = binaryArray.join('');
-  const base64String = btoa(binaryString);
+  const base64String = toBase64(buffer);
   const dataURL = `data:image/${format};base64,${base64String}`;
   return dataURL;
 }