I'm trying to make a DELETE
call and I'm implementing the function below. I understand that in a promise, there needs to be a "resolve" and a "reject" state, but I'm getting an unhandled promise rejection error:
UnhandledPromiseRejectionWarning: Unhandled promise rejection (rejection id: 1): [object Object]
I don't really like using conditional statements inside a promise because it gets messy, but what I'm trying to do here is to check if the organization is verified, and if it is, a delete operation should not occur and will reject.
function deleteOrg(id) {
return new Promise((resolve, reject) => {
// A helper function that returns an 'org' object
findById(id)
.then((orgObject) => {
if (orgObject.verified_at !== null) {
throw new Error(422, 'Unable to delete organization')
}
//Organization is not verified, so proceed to delete
new Organization().where({'id': id}).destroy()
.then(() => {
return resolve() //return 200 upon deletion
})
.catch((err) => {
return reject(new Error(500, 'Unable to delete organization'))
})
})
.catch((err) => {
const m = `Unable to delete organization: ${err.message}`
return reject(new Error(500, m))
})
})
}
I'm pretty sure I'm handling the rejection inside the if
wrong.
Creating promises inside promise constructors is a known anti-pattern . Try modularizing your promises into separate functions instead:
function deleteOrg(id) {
const verifyOrg = (orgObject) => {
if (orgObject.verified_at !== null) {
throw new Error(422, 'Unable to delete organization')
}
};
const destroyOrg = () => new Organization().where({
'id': id
}).destroy();
return findById(id)
.then(verifyOrg)
.then(destroyOrg);
}
Where you can let the errors propagate through the promise chain and handle them outside:
deleteOrg(id)
.catch((err) => {
const m = `Unable to delete organization: ${err.message}`;
// ...
});
as findById and .destroy return Promises, there is no need for the Promsie constructor
Your code is then simplified to
function deleteOrg(id) {
return findById(id)
.then((orgObject) => {
if (orgObject.verified_at !== null) {
throw new Error(422, 'Unable to delete organization')
}
//Organization is not verified, so proceed to delete
return new Organization().where({'id': id}).destroy()
.catch((err) => {
throw (new Error(500, `Unable to delete organization: ${err.message}`));
});
});
}
The technical post webpages of this site follow the CC BY-SA 4.0 protocol. If you need to reprint, please indicate the site URL or the original address.Any question please contact:yoyou2525@163.com.