I'm trying to check if the user with the email
provided exists in the collection users
, but my function keeps returning undefined for every call. I use es6 and async/await
in order to get rid of lots of callbacks. Here's my function (it is inside of a class):
async userExistsInDB(email) {
let userExists;
await MongoClient.connect('mongodb://127.0.0.1:27017/notificator', (err, db) => {
if (err) throw err;
let collection = db.collection('users');
userExists = collection.find({email: email}).count() > 0;
console.log(userExists);
db.close();
});
console.log(userExists);
return userExists;
}
So, the first console.log
inside the .connect
call always returns false
because the returned value of the .find
is not an array, it is some huge object which looks like this:
{ connection: null,
server: null,
disconnectHandler:
{ s: { storedOps: [], storeOptions: [Object], topology: [Object] },
length: [Getter] },
bson: {},
ns: 'notificator.users',
cmd:
{ find: 'notificator.users',
limit: 0,
skip: 0,
query: { email: 'email@example.com' },
slaveOk: true,
readPreference: { preference: 'primary', tags: undefined, options: undefined } },
options:
........
........
And the last console.log
is always undefined (although I think it shouldn't be like that, because await
waits for the end of the asynchronous call, right?)
I just need my function to return a boolean value, not a Promise
or something.
Can anybody help me with that?
UPDATE 1
console.log(collection.findOne({email: email}));
inside the .connect
returns this:
{ 'Symbol(record)_3.ugi5lye6fvq5b3xr':
{ p: [Circular],
c: [],
a: undefined,
s: 0,
d: false,
v: undefined,
h: false,
n: false } }
UPDATE 2
Seems like it was the issue with my poor knowledge of es7 async/await
.
Now the code inside the .connect
returns the needed value.
async userExistsInDB(email) {
let userExists;
await* MongoClient.connect('mongodb://127.0.0.1:27017/notificator', async(err, db) => {
if (err) throw err;
let collection = db.collection('users');
userExists = await collection.find({email: email}).limit(1).count() > 0;
db.close();
});
console.log(userExists); // <--- this is not called at all
return userExists;
}
However, now the console.log
or anything after the .connect
call is not performed at all.
Now, every time I call the userExistsInDB()
function somewhere and console.log
its result, I get this:
{ 'Symbol(record)_3.78lmjnx8e3766r':
{ p: [Circular],
c: [],
a: undefined,
s: 0,
d: false,
v: undefined,
h: false,
n: false } }
Any ideas why it is like that?