Try... Catch in async await not catching error [duplicate]

Question

Why the try...catch is not working for below sample code?

const http2 = require("http2")
const url = require("url")


function sendRequest() {
    return new Promise((resolve, reject) => {

        var r = http2.request({
            "host": "www.google.com",
            "method": "GET",
            "path": "/"
        }, (resp) => {
            var data = []
            resp.on("data", (chunk) => {
                throw ("Error")
            })
            resp.on("end", () => {
                console.log("ended")
                resolve("finished")
            })
            resp.on("error", (e) => {
                console.log("error")
                reject(e)
            })
        })
        r.end()
    })
}

async function wrapper(){
    try {
        console.log("Sending request")
        await sendRequest()
        console.log("Finished sending Request")
    }catch(e){
        console.log("error!") // Supposed to see this
        console.log(e)
    }
    console.log("All finished") // Supposed to see this
}

wrapper()

Output is as follow:

Sending request

/Users/test-user/test.js:15
                throw ("Error")
                ^
Error

Process finished with exit code 1

Answer 1

You can throw inside a promise and catch the error with catch so long as the error is in the promise itself and not in different async callback.

For example, the test() works as expected, but test2() does not:

function test(){
    return new Promise((resolve, reject) => {
        throw (new Error("error"))
    })
}

function test2(){
    return new Promise((resolve, reject) => {
        setTimeout(() => {
            throw (new Error("error"))
        }, 100)

    })
}
async function go (){
    try {
        await test()
    } catch(err){
        console.log("caught error from test(): ", err.message)
    }

    try {
        await test2()
    } catch(err){
        console.log("caught error from test2(): ", err.message)
    }

}
go()

Both cases work fine with reject() instead of throw()