FileReader readAsText() async issues?

Question

I have implemented the following code to parse a CSV via a selection:

export async function parse(file: File) {
           


        

Answer 1

await doesn't help here. readAsText() doesn't return a Promise.

You need to wrap the whole process in a Promise:

export function parse(file: File) {
  // Always return a Promise
  return new Promise((resolve, reject) => {
    let content = '';
    const reader = new FileReader();
    // Wait till complete
    reader.onloadend = function(e: any) {
      content = e.target.result;
      const result = content.split(/\r\n|\n/);
      resolve(result);
    };
    // Make sure to handle error states
    reader.onerror = function(e: any) {
      reject(e);
    };
    reader.readAsText(file);
  });
}