Is it possible to return a function for each element of an array and call it in Promise.all?

Question

JavaScript

Hello!
Tell me if it is possible to do this: I have an array of values, for each element of the array I need to go through and return an asynchronous function, inside which a request to the server will be executed (the parameter is the array element itself). In the future, I would like to wrap the result in Promise.all () so that the requests go in parallel. Is it possible?

My code that doesn't work:

const filePromises = filesToDelete.map((file: DocsManagerFile) => () => {
  httpService.sendDataTest(
     { data_in: { id: file.id } },
     'physdocs.delete_docs_file',
  );
});

await Promise.all(filePromises);

Answer 1

If the method httpService.sendDataTest(...)returns a promise, then you should not wrap it in an arrow function, like this:

filesToDelete.map((file: DocsManagerFile) => httpService.sendDataTest({ ... }))

And if not, it should accept onsuccess and onerror callbacks, then like this:

filesToDelete.map((file: DocsManagerFile) => (
  new Promise(onsuccess, onerror) => (
    httpService.sendDataTest(
       { data_in: { id: file.id } },
       'physdocs.delete_docs_file',
      // где-то тут onsuccess и onerror
    );
))));