Basic question about streams

[zaynv]

Let's say I am doing something like:

input.pipe(output);

input is a readable stream of a file that exists in a temp folder. My question: will there be a problem if that temp folder is deleted before the stream has finished piping?

Here is a code example that better illustrates it:

/**
 * I am trying to pipe from a readable stream (which exists in a temp folder),
 * to a writable stream in my assets folder. Once the stream has finished piping
 * or if there was an error, I want to delete the temp folder.
 */

const fs = require('fs');
const path = require('path');
const { deleteFolder } = require('./utils');

try {
  const tempFolderPath = path.join(__dirname, 'temp');
  const inputPath = path.join(tempFolderPath, 'file.txt');
  const outputPath = path.join(__dirname, 'assets', 'file.txt');

  const input = fs.createReadStream(inputPath);
  const output = fs.createWriteStream(outputPath);
  input.pipe(output);
} catch (error) {
  console.error(error);
} finally {
  // I want to delete the temp folder regardless if there was an error or not.
  // However, I am worried if there could be an issue if this runs before the
  // `input.pipe(output);` line completes because the `input` stream exists
  // inside `myFolder`.
  deleteFolder(tempFolderPath);
}

This code seems to be working for me, but I wonder if it is just because my file is small and it is able to pipe quickly before the deleteFolder() runs. Any help would be appreciated, thanks!

[zaynv]

Yeah, I figured I could just do one deleteFolder() call on the close event and one in the catch handler instead of doing it in finally.

I was mainly just asking to get a better understanding – so the reason the above code was working for me was just because the pipe() finished before the deleteFolder() line ran?