const { Base64 } = require('js-base64') export class Base64Message { private base64Message: string public length: number private constructor(base64Str: string) { this.base64Message = base64Str this.length = base64Str.length } public static toUnicodeString(message: Base64Message) { return Base64.decode(message.base64Message) } public static fromBuffer(buffer: Buffer) { return new Base64Message(buffer.toString('base64')) } public static fromString(str: string) { return new Base64Message(Base64.encode(str)) } public static toDataUri(message: Base64Message, mimeType: string) { return `data:${mimeType};base64,${message.base64Message}` } }