Is it possible to cancel an operation within a hook but still return success (and commit sub-operations?)

[drewbo]

I'm writing a multi-tenant application with some significant tenant isolation changes from the example/plugin. As part of this, I'm trying to implement an email uniqueness check with different validation rules. That is: if the user already exists in the DB and a tenant-admin attempts to add them to a new tenant, that operation should still "succeed" but be converted from a create to an update operation. Something like the following:

fields: [
      {
      name: 'email',
      type: 'email',
      required: true,
      access: {
        update: adminField,
      },
      hooks: {
        beforeValidate: [testEmailUniqueness]
      }
    }]
...

const testEmailUniqueness: FieldHook<User> = async({
  data, originalDoc, req, value, operation
}) => {
      ...
      // if the user matches the current tenant, this is a true validation error
      // if the user exists but on another tenant, modify that user

    ... (if first condition)
        throw new ValidationError({
          errors: [{
            message: `User with email ${value} exists for this tenant`,
            path: 'email',
          }]
        })
      } else {
        await payload.update({
          collection: 'users',
          id: existingUser.id,
          data: {
            tenants: [...data.tenants, ...existingUser.tenants]
          },
        })
        return false // unclear what return value should be
      }
  }

A few questions:

• Is this type of operation possible?
• What should the return value be from the hook?
• Is it still possible to wrap this all in the same DB transaction?