prisma: Prisma crashes with `This is a non-recoverable error which probably happens when the Prisma Query Engine has a panic.`

Bug description

Prisma panics on a valid query.

I make this Prisma call:

  await prisma.book_share_email_invitations.findOne({
    select: {
      id: true,
      book_id: true,
      book: {
        select: {
          id: true,
          name: true,
          shelf: { select: { id: true, name: true } },
        },
      },
      email: true,
      permission: true,
      // vvv This is the problematic part
      last_sent_user: {
        select: {
          id: true,
          name: true,
          first_name: true,
          last_name: true,
        },
      },
    },
    where: { auth_token },
  })

In the query, I request last_sent_user which is a relation based on the field last_sent_by (full schema shown later).

Additional details:

• This isn’t the default name for the relation which would be users; however, last_sent_user is more representative of what the relation is.
• The last_sent_user related record does exist. I checked it manually and the related users.id exists in the database.
• If I remove last_sent_user from the query, it executes without error.
• The book relation works fine.

The error is:

Error at path "api/pages/share/book/[auth_token].ts" on method "entry":
Invalid `prisma.book_share_email_invitations.findOne()` invocation in
/Users/sunnyhirai/Projects/airshelf/api/pages/share/book/[auth_token].ts:8:52

   4 async function getInvitation(
   5   [object Object], auth_token ,[object Object],[object Object], ,[object Object], auth_token,[object Object], string ,[object Object],[object Object],
   6   ,[object Object], prisma ,[object Object],[object Object], ,[object Object],[object Object],Context
   7 ) {
→  8   return await prisma.book_share_email_invitations.findOne(
  PANIC: Application logic invariant error: received null value for field last_sent_user which may not be null

This is a non-recoverable error which probably happens when the Prisma Query Engine has a panic.

As can be seen in the error, Prisma is expected to receive a value for last_sent_user:

SELECT "public"."book_share_email_invitations"."id", "public"."book_share_email_invitations"."book_id", "public"."book_share_email_invitations"."email", "public"."book_share_email_invitations"."permission", "public"."book_share_email_invitations"."book_id", "public"."book_share_email_invitations"."last_sent_by" FROM "public"."book_share_email_invitations" WHERE "public"."book_share_email_invitations"."auth_token" = $1 LIMIT $2 OFFSET $3

How to reproduce

I’ve provided details below but a minimal reproduction may be hard to create because my other relations work fine. I don’t know what is special about this one that makes it crash other than the naming is a little different (however, other relations are renamed to use a singular form in many cases).

Expected behavior

Should not panic.

Prisma information

These are the immediate models related to this query.

model book_share_email_invitations {
  auth_token   String @unique
  book_id      Int
  email        String
  id           Int    @default(autoincrement()) @id
  last_sent_by Int
  permission   Int
  // normalized (singularized)
  book        books  @relation(fields: [book_id], references: [id])
  // normalized (singularized)
  last_sent_user        users  @relation(fields: [last_sent_by], references: [id])

  @@index([book_id], name: "book_share_email_invitations_book_id_index")
  @@unique([book_id, email], name: "book_share_email_invitations_book_id_email_unique")
}

model users {
  created_at                   Int
  email                        String                         @unique
  first_name                   String
  id                           Int                            @id
  last_name                    String
  name                         String                         @unique
  password_hash                String?
  // normalized (singularized)
  shelf                      shelves                        @relation(fields: [id], references: [id])
  // normalized (no change)
  book_marks                   book_marks[]
  // normalized (no change)
  book_share_email_invitations book_share_email_invitations[]
  // normalized (no change)
  book_shares                  book_shares[]
  // normalized (no change)
  notifications                notifications[]
  // normalized (no change)
  page_edit_sessions           page_edit_sessions[]
  // normalized (no change)
  page_marks                   page_marks[]
  // normalized (no change)
  pages                        pages[]
  // normalized (no change)
  sessions                     sessions[]
  // normalized (no change)
  user_starred_books           user_starred_books[]
}

model books {
  counter                      Int                            @default(0)
  created_at                   Int
  id                           Int                            @default(autoincrement()) @id
  name                         String
  privacy                      Int
  shelf_id                     Int
  title                        String
  toc                          Json
  updated_at                   Int
  // normalized (singularized)
  shelf                      shelves                        @relation(fields: [shelf_id], references: [id])
  // normalized (no change)
  book_marks                   book_marks[]
  // normalized (no change)
  book_share_email_invitations book_share_email_invitations[]
  // normalized (no change)
  book_shares                  book_shares[]
  // normalized (no change)
  pages                        pages[]
  // normalized (no change)
  shelf_pinned_books           shelf_pinned_books[]
  // normalized (no change)
  user_starred_books           user_starred_books[]

  @@unique([shelf_id, name], name: "books_shelf_id_name_unique")
}

Environment & setup

• OS: Mac OS
• Database: PostgreSQL
• Prisma version: 2.0.0
• Node.js version: v12.16.2