A simplified example is this:

function core() { return new Promise(async (fulfill, reject) => { // Promise constructor的参数的返回值是被无视的 // 加个async不会导致新Promise被连接到fulfill或reject // 所以下面的那个Promise不会被then或catch，成为你看到的现象 return Promise.reject(new Error("core exception rises")); }); }; core();

Change:

return new Promise(async (resolve, reject) => { try { await wrapper(); } catch(error) { reject(new Error("core exception rises")); } });

or:

return (async function( ) { try { await wrapper(); } catch(error) { console.error(error.message); throw new Error("core exception rises"); } }());

The problem with your code is thatcore exception risesThePromisein this place has neitherresolvenorreject, so what do you do? ^^

Why can I get the expected results only by making the following modifications? Is it related to microtask? Can anyone help explain it clearly?

'use strict'; function core() { function wrapper() { return new Promise((resolve, reject) => { throw new Error("wrapper exception rises"); }); } return new Promise(async (resolve, reject) => { try { await wrapper(); } catch(error) { console.error(error.message); //throw new Error("core exception rises"); reject(new Error("core exception rises")); } }); } (async function() { try { await core().catch(err => { console.log("core promise rejected - " + err.message); throw new Error("main exception propagated"); }); } catch(error) { console.error(error.message); console.error("Got it in main scope"); } })();

The result of the operation is:

wrapper exception rises core promise rejected - core exception rises main exception propagated Got it in main scope