NodeJS: Why is this code throwing a warning? - node.js

Question

I have the following code, it works but it still throws the warning.
I'm running in Node v12.
(node:15985) UnhandledPromiseRejectionWarning: Unhandled promise rejection. This error originated either by throwing inside of an async function without a catch block, or by rejecting a promise which was not handled with .catch(). (rejection id: 3)
Here is the source code for the loop, thanks:
const links = await knex('links').where('active', true);
const links = await knex('links').where('active', true).catch((e) => console.log(e)) // does not work neither
for (let index = 0; index < links.length; index++) {
const element = links[index];
console.log('Running with', index, element.uri);
(async () => {
try {
const { statusCode } = await got({
url: `${element.protocol}://${element.uri}:${element.port}`,
method: 'GET',
timeout: 5000
})
const check = {
statusCode: statusCode,
}
await knex('checks').insert(check);
} catch (error) {
const check = {
status: 'error',
}
await knex('checks').insert(check);
}
})().catch(() => {});
}

Answer 1

You have 2 promises without a catch block:
As pointed by #Phix in the comment, one on the first line:
// On the first line
await knex('links').where('active', true)
In the catch block at the end of the code:
await knex('checks').insert(check);

Answer 2

I made some change to the original code according to my understanding. I also suspect await knex('checks').insert(check); is the issue for the unhandled promise. So I added a try & catch to handle it. The finally is not required. I just want to make the flow a bit clear. I hope it solve the issue, at least provide some ideas.
// assign the async salad to a const to make the flow a bit more clear
const fetchData = async () => {
try {
let check;
const { statusCode } = await got({
url: `${element.protocol}://${element.uri}:${element.port}`,
method: 'GET',
timeout: 5000
})
check = {
statusCode: statusCode,
};
} catch (error) {
check = {
status: 'error',
}
} finally {
// use a try catch to handle the potential async call
try {
await knex('checks').insert(check);
} catch {
throw new Error('Error')
}
}
};
// if await knex('checks').insert(check) fails, we can catch the error it throws
try {
fetchData()
} catch (erroe) {
console.log(error);
}