chore: add toBase64

Author: Simon he

src/toBase64.ts

@@ -0,0 +1,31 @@
+import { FileType } from './types'
+export async function toBase64(o: File | string, type: FileType = 'url') {
+  if (type === 'file' || type === 'blob')
+    return await fileToBase64(o as File | Blob)
+  else if (type === 'url')
+    return await urlToBase64(o as string)
+}
+
+export function fileToBase64(file: File | Blob) {
+  return new Promise((resolve, reject) => {
+    let reader = new FileReader();
+    reader.readAsDataURL(file)
+    reader.onload = function (e) {
+      resolve(e?.target?.result)
+    }
+  })
+}
+
+export function urlToBase64(url: string) {
+  return new Promise((resolve, reject) => {
+    const canvas: HTMLCanvasElement = document.createElement('canvas'),
+      ctx = canvas.getContext('2d'),
+      img = new Image;
+    img.crossOrigin = 'Anonymous';
+    img.src = url + "?timeStamp=" + new Date().getTime();
+    img.onload = function () {
+      ctx?.drawImage(img, 0, 0, canvas.width = img.width, canvas.height = img.height);
+      resolve(canvas.toDataURL())
+    };
+  })
+}