Display values passed into a lambda

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1

Hi,

I’m trying to learn how faunadb works, and I’m looking for a way to debug what is going on in my UDFs, privilege functions, etc.

I’m trying to debug my “create” privilege function. I’m using graphql, and my schema looks like this:

type User {
  email: String! @unique
  company: Company!
}

type Company {
  name: String! @unique
  users: [User!]! @relation
}

When a new user registers, I want them to create the user, and then create a new company, with the new user associated, but I want to make sure users can only create companies with themselves associated, and then I plan to build out the other rules so only company users can edit / delete / read their own company as well. The user gets created just fine, but when I try and create the new company, I run into permission issues.

My graphql mutation looks like this:

variables = {
  data: {
    name: "foo",
    users: {
      connect: [userId], //this is the newly created user id
    },
  },
}

mutation createCompany($data: CompanyInput!) {
  createCompany(data: $data) {
    _id
    name
  }
}

and the role privileges looks like this:

{
  resource: Collection("Company"),
  actions: {
    read: true,
    write: true,
    create: Query(
      Lambda(
        "values",
        ContainsValue(Identity(), Select(["data", "users"], Var("values")))
      )
    ),
    delete: true,
    history_read: false,
    history_write: false,
    unrestricted_read: false
  }
},

I’ve tried Equals(Identity(), Select([“data”, “users”], Var(“values”)))
and I’ve tried ContainsValue(Identity(), Select([“data”, “users”, “connect”], Var(“values”)))

nothing seems to work, and I can’t tell what’s going on. Currently, I’m just messing around with trial and error, so my real question is, can I output the value of “data” that gets passed to the lambda somehow so i can see what’s getting passed into the lambda when the mutation is executed? That way I could at least dump it to the shell and play around there.

2

Ok I’ve done a little more testing and was able to write a function that returns true when written as a UDF:

it looks like this:

Query(
  Lambda(
    "values",
    ContainsValue(
      Select("id", CurrentIdentity()),
      Select(["data", "users", "connect"], Var("values"))
    )
  )
)

When i run
Call(“test”, {“data”:{“name”:“MY_COMPANY_NAME”,“users”:{“connect”:[“MY_USER_REF”]}}}) I get back true.

strange thing is, when I set it up as a privilege, it still isn’t working, leading me to believe that the data gets changed before the privilege gets invoked.

3

Lol just figured it was happening because the role didn’t have write access to users, enabling that fixed it. That being said, It still took about a day and a half of trial and error to figure out, so if anyway has some tips for debugging these that would be awesome, thanks!

4

Wanted to share this logging function post I just created in case it’s of use!

5

Thanks! I just voted for that feature.

It’d be great if they had a proper log however, or better yet some type of ide where you could write a UDF or Privilege function that attaches to the database and allows you to step through execution to debug. I can see it being a lot to ask, however they’re trying to sell faunadb as your entire backend so tooling like this will definately be necessary.

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