Cannot send PNG via express route

Question

I have an png image which I am serving from my express endpoint, the image should be readable as an image source. I have currently got the image as a buffer in node and I am trying to render it however I cannot seem to get the image to appear.

Outcome

Expected

Express JS Code

publicController.get('/avatar', async (req, res, next) => {
  const image = await PUBLIC.avatar();
  res.writeHead(200, {
      'Content-Type': 'image/png',
      'Content-Length': image.toString("binary").length
    });
  res.charset = 'binary';
  res.write(image.toString("binary"));
  res.end()
})

Tried Methods:

• Piping from a readable stream
• Convert to base 64 and render
• Convert to binary and pipe
• Convert to binary and render
• Dump raw png file

Considerations:

• I have checked and the PNG file is correct, I created a file from the buffer and the PNG renders perfectly.
• The png image is dynamic dependant on several factors hence why I cannot place in an object storage like s3.

Answer 1

res.write(image.toString("binary"));

This isn't appropriate. If you have a buffer already, don't convert it. Write it out immediately.

res.writeHead(200, {
  'Content-Type': 'image/png',
  'Content-Length': image.length;
});
res.end(image);

Answer 2

Have you tried this?

// assuming image is a Buffer
  res.writeHead(200, {
      'Content-Type': 'image/png' // drop Content-Length as it should be automatically added by express
    });
  res.end(image);