Returning raw binary

[GeoSnipes]

I have this function reference below. The issue is Whenever it returns data it seems to be double the size of the actual file. If I open the file in a file editor the contents look the same however when running fc /b and comparing the files nearly everything is different. How can I return the raw binary data?

const fs = require('fs');
 
exports.handler = async (event) => {
   function getBinary (stream) {
   	const chunks = [];
   	let data = '';
   	return new Promise((resolve) => {
   		stream.on('data', (chunk) => {
   			chunks.push(Buffer.from(chunk, "binary"));
   			data += chunk;
   		});
   		stream.on('end', () => resolve(true ? Buffer.concat(chunks).toString('binary') : data)); 
   	});
   }
   
   let readStream = fs.createReadStream('sourcepdf.pdf', {encoding: 'binary'});
   const result = await getBinary(readStream);
   return result;
};

[aduh95]

How can I return the raw binary data?

One way of doing it would be to use readFile:

const fs = require('fs');
 
exports.handler = async (event) => {
   const result = await fs.promises.readFile('sourcepdf.pdf');
   return result;
};

That can even be a one-liner:

const fs = require('fs/promises');
 
exports.handler = () => fs.readFile('sourcepdf.pdf');

Is there a reason for not using readFile?

it seems to be double the size of the actual file

My guess would be it's because you convert the result to a string in your function, raw data is usually easier to deal with as TypedArray in JS (which is what readFile returns by default).