🐛 Bug Report

stream.xlsx.WorkbookReader.parse() does not cleanup the temporary xml files it creates if iteration is stopped prematurely.
This happens whenever iteration is prematurely stopped, e.g.:

const workbookReader = new exceljs.stream.xlsx.WorkbookReader(/*...*/);
for await (const worksheetReader of workbookReader) {
  // stop iteration
  break;
}

which causes all temporary xml files generated by the WorkbookReader to not be cleaned up until process termination.
This is primarily a problem for long-running server applications, since those may be up for very long timespans (i noticed this bug due to 50GB+ of xml files hanging around in the tmp directory of an express application that had been running for ~ 2 months)

Lib version: 4.3.0

Steps To Reproduce

Here's a code example that demonstrates the problem:

• any-excel-file.xlsx can be any excel file (contents don't matter)

• For exampleGood() "Cleanup called" will be outputted for each worksheet in the excel file (and the associated temporary file will be deleted)

• For exampleBad() "Cleanup called" will NEVER be outputted, and all associated temporary files will remain until process termination.

const exceljs = require("exceljs");
const fs = require("fs");
const tmp = require("tmp");

// hooking tmp.file to output "Cleanup called" whenever
// the cleanupCallback gets called
const origTmpFile = tmp.file;
tmp.file = function(cb) {
  origTmpFile(function(err, path, fd, cleanupCallback) {
    cb(err, path, fd, function() {
      console.log("Cleanup called");
      cleanupCallback();
    });
  });
};

async function exampleGood() {
  const workbookReader = new exceljs.stream.xlsx.WorkbookReader(fs.createReadStream("./any-excel-file.xlsx"), {});
  for await (const worksheetReader of workbookReader) {
    // iteration will run until the end
  }
}

async function exampleBad() {
  const workbookReader = new exceljs.stream.xlsx.WorkbookReader(fs.createReadStream("./any-excel-file.xlsx"), {});
  for await (const worksheetReader of workbookReader) {
    // aborting iteration prematurely
    // throw or return would have the same effect
    break;
  }
}


async function main() {
  console.log("GOOD:");
  await exampleGood();

  // "Cleanup called" will NOT be outputted in this case:
  console.log("BAD:");
  await exampleBad();

  console.log("DONE");
}

main();

The expected behaviour:

Temporary files should be cleaned up if iteration stops before reaching the end.

Possible solution (optional, but very helpful):

for await / for in javascript will automatically call .return() on the (async-) iterable if it doesn't complete iteration (to give the iterable a chance to cleanup)

For (async-)generator iterables .return() will result in finally blocks around the yield statement to be executed, e.g.:

async function* foo() {
  try {
    yield 1;
    console.log("AFTER YIELD");
    yield 2;
    yield 3;
  } finally {
    console.log("FINALLY");
  }
}

for await(const _ of foo()) {
  break;
}

will output "FINALLY" (but NOT "AFTER YIELD")

So in this case adding a large try-finally around parse() should suffice to cleanup the temporary files.