UnhandledPromiseRejectionWarning in Node/MongoDB async await scenario

Question

I'm just transitioning to async/await and have been learning from these resources:

https://javascript.info/async-await

https://medium.com/@rafaelvidaurre/truly-understanding-async-await-491dd580500e

https://hackernoon.com/understanding-async-await-in-javascript-1d81bb079b2c

I think I have understood the main points:

1. adding async before a function definition will ensure any value returned is a promise

2. adding await before the call to the async function will "pause" the program until a result is returned

3. the function that contains await must also have the async keyword before its declaration (any 'parent' functions of the container do not require the async keyword)

4. the 'await-dependent' declarations should be wrapped in a try/catch block

So I am thinking an ideal async/await scenario would look like this:

async function thisWillTakeAges() {

    // query a database, fetch external content etc
    return desired_value;

}


async function iLoveProgramming() {

    try {
        var desired_value = await thisWillTakeAges();
    } catch (err) {
        console.log(err);
        return;
    }

    // do things with 'desired_value' once it has been returned

}

I am trying to incorporate this into an application with the following code:

function get_reset_password_secret(reset_password_user_id) {

    // ...

    collection.findOne(query, options, async function(err, result) {
        if (err) {
            res.send(err);
        } else {

            if (result !== null) {

                // ..

                return secret;

            }
        }
    });

}


// middleware
const api_resource_get = async (req, res) => {

    // ...

    try {
        var secret = await get_reset_password_secret(reset_password_user_id);
    } catch (err) {
        console.log("error here at api_resource_get(): " + err);
    }

    var forgotten_password_token = jwt.sign({ user_email: user_email }, secret);

    // ... 

}


// route handler
app.route("/api/:api_version/resource")
    .get(api_resource_get);

I am getting this error:

(node:14484) UnhandledPromiseRejectionWarning: Error: secretOrPrivateKey must have a value

So there are two issues:

• Why am I getting this error?
• Why is the program stating that the error is unhandled when I do have a try/catch block (which is not console logging the error)?

In regards to the first issue, perhaps it is because get_reset_password_secret() also needs the async keyword before it?

In regards to the second issue, I'm not sure why the catch block is not being recognised.