JSFiddle - React, Tailwind, and code Playground

by msfrisbie

JavaScript

let p1 = Promise.reject('foo');

// No handler function acts as a passthrough
let p2 = p1.catch();

console.log(p2);  // Promise <resolved>: foo

// These are equivalent
let p3 = p1.catch(() => undefined);
let p4 = p1.catch(() => {});
let p5 = p1.catch(() => Promise.resolve());

console.log(p3);  // Promise <resolved>: undefined
console.log(p4);  // Promise <resolved>: undefined
console.log(p5);  // Promise <resolved>: undefined

// These are equivalent
let p6 = p1.catch(() => 'bar');
let p7 = p1.catch(() => Promise.reject('bar'));

console.log(p6);  // Promise <resolved>: bar
console.log(p7);  // Promise <resolved>: bar

let p8 = p1.catch(() => new Promise(() => {}));

console.log(p8);  // Promise <pending>