feat: new function - base64ToFile

README.md

@@ -115,6 +115,7 @@ pnpm add @utopia-utils/dom
 * onTimeout: wrap for setTimeout, return a function to remove the timeout。[source](https://github.com/GreatAuk/utopia-utils/blob/main/packages/core/src/onTimeout.ts)
 * onWindowFocus: 监听 window focus 和 visibilitychange 事件，当窗口可见时，触发回调。[source](https://github.com/GreatAuk/utopia-utils/blob/main/packages/core/src/onWindowFocus.ts)
 * formatNumberThousand: 数字千分位格式化。[source](https://github.com/GreatAuk/utopia-utils/blob/main/packages/core/src/formatNumberThousand.ts)
+* base64ToFile: base64 转 File, 如图片裁剪时，我们获取到的是 base64，但上传接口一般需要 formData 上传。[source](https://github.com/GreatAuk/utopia-utils/blob/main/packages/core/src/ base64ToFile.ts)
 ### 类型判断
 
 ```bash

packages/core/src/base64ToFile.test.ts

@@ -0,0 +1,17 @@
+/**
+ * @vitest-environment happy-dom
+ */
+
+import { describe, expect, it } from 'vitest'
+
+import { base64ToFile } from './base64ToFile'
+
+describe('base64ToFile', () => {
+  it('should convert a base64 string to a File object', () => {
+    const base64 = 'data:image/jpeg;base64,/9j/4AAQSkZJRgABAQAAAQABAAD/2wCEAAkGBxQTEhQUExQWFhQYGBgYGBgYGBgYGBgYGBgYGBgYGBgYHSggGBolGxgXITEhJSkrLi4uGB8zODMsNygtLisB'
+    const file = base64ToFile(base64, 'test.jpg')
+    expect(file).toBeInstanceOf(File)
+    expect(file.name).toBe('test.jpg')
+    expect(file.type).toBe('image/jpeg')
+  })
+})

packages/core/src/base64ToFile.ts

@@ -0,0 +1,19 @@
+/**
+ * The function converts a base64 string to a File object with the specified filename and optional
+ * mimeType.
+ * @param {string} base64 - A string representing the base64 encoded data of the file.
+ * @param {string} filename - The `filename` parameter is a string that represents the desired name of
+ * the file that will be created from the base64 data.
+ * @returns a File object.
+ */
+export function base64ToFile(base64: string, filename: string): File {
+  const arr = base64.split(',')
+  const mime = arr[0].match(/:(.*?);/)![1]
+  const bstr = atob(arr[1])
+  let n = bstr.length
+  const u8arr = new Uint8Array(n)
+  while (n--)
+    u8arr[n] = bstr.charCodeAt(n)
+
+  return new File([u8arr], filename, { type: mime })
+}