生产和本地代码的行为不同

Question

I have a Loopback app where I have created some seed scripts to pre-populate the db.

Here is the seed

const remote = {
    "name": "remote",
    "email": "remote@ttt.com",
    "password": "arglebargle"
}

app.models.AppUser.find({where: {email: 'remoteUser@ttt.com'}})
    .then(res => {
        if (res.length === 0) {
            createUsers(remote, 'remote')
        } else {
            console.log('remote user already exists')
        }
    })

This calls createUsers which is below

const app = require('../server')
const Promise = require('bluebird');

module.exports = {
  createUsers: (userInfo, roleName) => {
    if (!userInfo || !roleName) {
      let err = new Error('please give valid user and role names')
      console.log(err)
      return err
    }
    console.log(userInfo)
    return app.models.AppUser.findOrCreate({where: {'name': userInfo.name}}, userInfo)
      .then((instance) => {
        return app.models.Role.findOne({where: {name: roleName}})
          .then((role) => {
              return role.principals.create({
              principalType: app.models.RoleMapping.USER,
              principalId: instance[0].id //find or create returns an array
          })
        })
      })
      .catch((error) => {
        return error
      })
    }
  }

The above probably isn't good promise based code. But this is working fine in other situations so I am not sure if I can blame it.

Running the above script creates the 'remote' user and assigns the 'remote' role to it locally, however it does not do anything in production and I just cannot figure out why.

The only other difference I can think of between production and local is that the I am calling them from different locations (the project root is different)

Answer 1

I see a couple issues here. First, in this block:

  createUsers: (userInfo, roleName) => {
    if (!userInfo || !roleName) {
      let err = new Error('please give valid user and role names')
      console.log(err)
      return err
    }
    console.log(userInfo)
    return app.models.AppUser.findOrCreate

you're returning an Error and a Promise from one function. Then here:

    if (res.length === 0) {
        createUsers(remote, 'remote')
    } else {
        console.log('remote user already exists')
    }

you're ignoring the return value altogether from createUsers

I'd stick with promises, as that seems to be the direction you're going, like so:

createUsers: (userInfo, roleName) => {
  if (!userInfo || !roleName) {
    let err = new Error('please give valid user and role names')
    console.log(err)
    return Promise.reject(err)
  }
  ...

and you must handle every promise, otherwise it will silently fail.

if (res.length === 0) {
  createUsers(remote, 'remote')
    .then(result => console.log('got a result'))
    .catch(error => console.error('oh no!', error))
} else ...

And also, the first AppUser.find is not being handled if there is an error:

app.models.AppUser.find({where: {email: 'remoteUser@ttt.com'}})
   .catch(err => console.error('yikes!', err))
   .then(res => {

The code you have now will silently swallow any errors that occur in createUsers or that first call. So, something like the database being unreachable in production would never present itself.

Hope this helps!