How to return a promise when writestream finishes?

by

You’ll want to use the Promise constructor:

function writeToFile(filePath: string, arr: string[]): Promise<boolean> {
  return new Promise((resolve, reject) => {
    const file = fs.createWriteStream(filePath);
    for (const row of arr) {
      file.write(row + "\n");
    }
    file.end();
    file.on("finish", () => { resolve(true); }); // not sure why you want to pass a boolean
    file.on("error", reject); // don't forget this!
  });
}

More Related Contents:

  1. When is .then(success, fail) considered an antipattern for promises?
  2. Is it bad practice to have a constructor function return a Promise?
  3. Use async await with Array.map
  4. Correct way to write loops for promise.
  5. Asynchronous exception handling with bluebird promises
  6. Promise Retry Design Patterns
  7. Handling multiple catches in promise chain
  8. Write / add data in JSON file using Node.js
  9. return value after a promise [duplicate]
  10. Angular 2 Karma Test ‘component-name’ is not a known element
  11. Why do I need to await an async function when it is not supposedly returning a Promise?
  12. Catching Errors in JavaScript Promises with a First Level try … catch
  13. Are there still reasons to use promise libraries like Q or BlueBird now that we have ES6 promises? [closed]
  14. Mongoose the Typescript way…?
  15. using async await and .then together
  16. Why cant I inline call to res.json?
  17. How to implement a pseudo blocking async queue in JS/TS?
  18. TypeScript import/as vs import/require? [duplicate]
  19. Proper way to skip a then function in Q Promises
  20. Is it a good practice using Observable with async/await?
  21. Why is my function returning Promise { } [duplicate]
  22. Typescript Promise rejection type
  23. Difference of using async / await vs promises?
  24. Javascript Asynchronous Exception Handling with node.js
  25. Promise.all().then() resolve?
  26. Recursive Promises Not Returning
  27. Properly batch nested promises in Node
  28. JavaScript asynchronous programming: promises vs generators
  29. Property ‘XXX’ does not exist on type ‘CombinedVueInstance’
  30. How to Promisify this function – nodejs [duplicate]

Leave a Comment