createUser.js

// This is the firebase script called to create each user.

exports.createUser = functions.https.onCall((data) => {
  const user = data.user[0]

  let displayName = `${user.firstName} ${user.lastName}`

  return admin.auth().createUser({
    displayName: displayName,
    email: user.email,
    emailVerified: false,
    password: user.password
  })
  // the createUser firebase function returns a userRecord.
    .then(function (userRecord) {
      // create a reference to a new document in the user collection with the user's uid.
      let userRef = admin.firestore().collection('users').doc(userRecord.uid)
      let userObj = {
        // * This creates the actual user record in the users collection.
        active: true,
        displayName: userRecord.displayName,
        email: user.email,
        emailVerified: false,
        firstName: user.firstName,
        fullName: `${user.lastName}, ${user.firstName}`,
        lastName: user.lastName,
        photoURL: '',
        role: user.role,
        uid: userRecord.uid
      }

      
      // I use each new user's institutional email address to assign an institution record. It uses the next to last word in their email address.
      let array = user.email.split('@')
      userObj.username = array[0]
      userObj.institution = array[1].split('.').slice(-2).join('.')

      return userRef.set(userObj)
        .then(() => {
          return { text: `Successfully created new user: ${userRecord.displayName}` } // successMessage in the other script.
        })
        .catch(error => {
          console.log(error)
        })
    })
    .catch(function (error) {
      // return { text: `Error creating new user ${user.email}:${errorMessage}` } // errorMessage in the other script.
      return { text: `${error}` }
    })
})