Convert a readable stream to base64 string

streamToBase64.js

/**
 * Convert a Readable Stream to base64 string
 * @param {ReadableStream} stream - a readable stream to convert in base64 string
 * @returns {Promise} - Promise that resolve in a string containing the base64
 */
const streamToBase64 = (stream) => {
  const concat = require('concat-stream')
  const { Base64Encode } = require('base64-stream')

  return new Promise((resolve, reject) => {
    const base64 = new Base64Encode()

    const cbConcat = (base64) => {
      resolve(base64)
    }

    stream
      .pipe(base64)
      .pipe(concat(cbConcat))
      .on('error', (error) => {
        reject(error)
      })
  })
}

// Example: https://repl.it/@luan0ap/streamToBase64

Hello, when I am trying to convert the stream to base64 by using above code it will give an error .

TypeError: stream.pipe is not a function. (In 'stream.pipe(base642)', 'stream.pipe' is undefined)

This is a Node API. In the browser, you would do something like that (Typescript):

export async function readAsDataUri(file: File): Promise<string> {
  return new Promise((resolve, reject) => {
    const reader = new FileReader();
    reader.addEventListener('loadend', (e) => {
      if (typeof reader.result === 'string') {
        resolve(reader.result);
      } else {
        reject(reader.error);
      }
    });
    reader.readAsDataURL(file);
  });
}

To only get the base64 string, you need to split and get the latter part.