什么是process._tickCallback Node.js错误

Question

Me and my friend working on project in node.js. We had a error which we don't know what it is. Can you guys explain about it? Here's the error:

at process._tickCallback (internal/process/next_tick.js:188:7)
(node:10758) UnhandledPromiseRejectionWarning: Unhandled promise rejection. This error originated either by throwin
g inside of an async function without a catch block, or by rejecting a promise which was not handled with .catch().
 (rejection id: 2335)

PS: My friend didn't allow me to post code.

Answer 1

This error happens when developers forget adding async error handling via .catch() or try... catch . Compare:

(async function main() {
  try {
    await Promise.reject();
  } catch (err) {
    console.error('Rejection handled.');
  }
})();

Rejection handled.

(async function main() {
  await Promise.reject();
})();

UnhandledPromiseRejectionWarning: ...