Promise that doesn't catch

Question

I was doing some Prisma requests and I noticed that some Promises weren't working.

I know I could use async-await, but this should work.

prisma
  .user({ uid })
  .then(user => {
    if (Object.keys(user).length) throw 'error!'

    return prisma.updateUser({
      data: { money: user.money - 50 },
      where: { id: user.id }
    })
  })
  .then(user => {
    prisma
      .createLog({
        user: { connect: { id: user.id } },
        type: 'TICKET_BOUGHT',
        date: new Date()
      })
      .then(() => console.log('Ticket bought'))
  })
  .catch(error => console.error(error))

If the user doesn't exist, it should throw an error, but instead the second 'then' is run.

Does it by any chance throw an error when a user does exist? — Luca Kiebel, Sep 14 '19 at 20:04
@EugeneSunic is a Prisma function. It gets an user of a database. https://prisma.io — JuanM04, Sep 14 '19 at 20:30
@JuanM04 is there a possibility to test your code somewhere online? — EugenSunic, Sep 14 '19 at 20:31

score 1 · Answer 1 · answered Sep 14 '19 at 20:09

1

Try this:

 if (!Object.keys(user).length) throw 'error!'

answered Sep 14 '19 at 20:09

EugenSunic

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A brief explanation has a lot more value than *"try this"* which is virtually meaningless – charlietfl Sep 14 '19 at 20:20
I'm testing and, don't ask me why, nothing works – JuanM04 Sep 14 '19 at 20:20
the please expose your .user({ uid }) promise – EugenSunic Sep 14 '19 at 20:21

Yasser Mas · Answer 2 · 2019-09-14T22:30:56.777

if (Object.keys(user).length) throw 'error!' that's mean if user exists, because object.keys function will return array list of object keys .length checking array length,

so if user exists ? Object.keys will return array list of user properties, that's mean length will be greater than zero and if condition will be true so throw will run,

If user not exist Object.keys will return zero and if(0) equal false so the throw will not run

In your case you should check if( ! Object.keys(user).length ) or if( Object.keys(user).length === 0 ) or you can check if( !user || user == {} ) or if( !user || !user.uid) instead of uid you can change it to any required property and you are sure 100% this property will return in all cases

Promise that doesn't catch

2 Answers2