Difference in error handling for async/await and callbacks

test.js

const request = require("request");
const express = require("express");
const util = require("util");

const app = express();
const requestPromise = util.promisify(request);
const timeoutPromise = util.promisify(setTimeout);

const getImgUrl = function(hostname, comicId, cb) {
	request(`https://${hostname}/${comicId}/info.0.json`, function(err, resp, body) {
		console.log("resp", resp);
		if (err) { return cb(err); }
		
		var temp = JSON.parse(body);
		
		return cb(null, temp.img);
	});
}

const timeoutTest = function(cb) {
	setTimeout(function() {
		throw new Error("dead!");
	}, 10);
}

const timeoutTestPromise = async function() {
	await timeoutPromise(10);
	throw new Error("dead!");
}

const getImgUrlPromise = async function(hostname, comicId) {
	const resp = await requestPromise(`https://${hostname}/${comicId}/info.0.json`);
	return JSON.parse(resp.body).img;
}

app.get("/", function(req, res, next) {
	var urls = [
		"/callback_valid/",
		"/callback_cb_error/",
		"/callback_thrown_error/",
		"/callback_timeout/",
		"/promise_valid/",
		"/promise_cb_error/",
		"/promise_thrown_error/",
		"/promise_timeout/"
	];
	
	var html = urls.map(val => `<p><a href="${val}">${val}</a></p>`).join("");
	
	res.send(html);
});

app.get("/callback_valid/", function(req, res, next) {
	getImgUrl("xkcd.com", 2036, function(err, img) {
		if (err) { return next(err); }
		
		res.send(`<img src='${img}'/>`);
	});
});

app.get("/callback_cb_error/", function(req, res, next) {
	getImgUrl("ashfdakshdfajsdhfkjsa.com", "bogus", function(err, img) {
		if (err) { return next(err); }
		
		res.send(`<img src='${img}'/>`);
	});
});

// process crash!
app.get("/callback_thrown_error/", function(req, res, next) {
	getImgUrl("xkcd.com", "bogus", function(err, img) {
		if (err) { return next(err); }
		
		res.send(`<img src='${img}'/>`);
	});
});

app.get("/callback_timeout/", function(req, res, next) {
	// this try/catch obviously won't work...
	try {
		timeoutTest();
	} catch(e) {
		return next(e);
	}
});

app.get("/promise_valid/", async function(req, res, next) {
	try {
		var img = await getImgUrlPromise("xkcd.com", 2036);
	} catch(e) {
		return next(e);
	}
	
	res.send(`<img src='${img}'/>`);
});

app.get("/promise_cb_error/", async function(req, res, next) {
	try {
		var img = await getImgUrlPromise("xkcd.com", "bogus");
	} catch(e) {
		return next(e);
	}
	
	res.send(`<img src='${img}'/>`);
});

app.get("/promise_thrown_error/", async function(req, res, next) {
	try {
		var img = await getImgUrlPromise("xkcd.com", "bogus");
	} catch(e) {
		return next(e);
	}
	
	res.send(`<img src='${img}'/>`);
});

app.get("/promise_timeout/", async function(req, res, next) {
	try {
		await timeoutTestPromise();
	} catch(e) {
		return next(e);
	}
});

app.listen(8080, function(err) {
	if (err) { throw err; }
	
	console.log("booted");
});