Idiomatic JavaScript

A collection of tips and tricks I saw online that helps to write idiomatic JavaScript. Please, feel free to submit your pull requests to add more.

Table of Contents

• Objects
• Helpers

Objects

• Create a new object from a combination of other objects:

  const newState = { ...state, ...changes };

  Source: https://twitter.com/jaffathecake/status/953579387726811136?s=12

• Conditional object extension:

  const obj = {
    ...condition && { property: value },
  };

  Source: https://dev.to/jfet97/the-shortest-way-to-conditional-insert-properties-into-an-object-literal-4ag7

Helpers

• Delay 'polyfill':

  const wait = (timeout) => (new Promise(resolve => setTimeout(resolve, timeout)));

  Usage:

  // Promises
  wait(500).then(() => doSomething());
  
  // async/await
  await wait(500);
  doSomething();

  Source: https://twitter.com/JakeDohm/status/1118973133443207179

• Go-like results handling¹:

  function O_o(promise) {
    return promise.then(data => {
      if (data instanceof Error) return [data];
      return [null, data];
    }).catch(err => [err]);
  }
  
  // Usage:
  async function usageExample(params) {
    const [err, data] = await O_o(myPromise(params));
  
    if (err) {
      // Handle or throw.
    }
  
    // Do stuff with data.
    return data;
  }

  Source: https://twitter.com/davidwells/status/1119729914876284928

Footnotes

1. Not quite idiomatic, but still cool and useful :-) ↩