Hooks values originalDoc and previousDoc are badly typed

[peufo]

Bug Report

The values originalDoc and previousDoc passed to functions of type FieldHook, CollectionBeforeChangeHook and CollectionAfterChangeHook do not match.

1. There is no distinction between beforeChange and afterChange field hooks. This makes in the beforeChange hook, previousDoc is typed as defined when it is not (as mentioned in the documentation)

2. In most cases, the document has "_id" and "__v" fields instead of simple "id".

Steps to Reproduce

Create this collection config :

import type {
  CollectionConfig,
  CollectionBeforeChangeHook,
  CollectionAfterChangeHook,
  FieldHook,
} from 'payload/types'

/* Result of "payload generate:types" */
interface IDoc {
  id: string
  name?: string
  createdAt: string
  updatedAt: string
}

interface IDocWithNativeFields extends IDoc {
  _id?: string
  __v?: number
}

function testDocType(labels: string[], doc: IDocWithNativeFields) {
  const correct = doc && doc.id && !doc._id && !doc.__v
  console.log(correct ? '✔️' : '❌', labels.join('\t'))
}

const fieldBeforeChange: FieldHook<IDoc> = ({ originalDoc, previousDoc }) => {
  testDocType(['field', 'beforeChange', 'previousDoc'], previousDoc)
  testDocType(['field', 'beforeChange', 'originalDoc'], originalDoc)
}

const fieldAfterChange: FieldHook<IDoc> = ({ originalDoc, previousDoc }) => {
  testDocType(['field', 'afterChange', 'previousDoc'], previousDoc)
  testDocType(['field', 'afterChange', 'originalDoc'], originalDoc)
}

const collectionBeforeChange: CollectionBeforeChangeHook<IDoc> = ({
  originalDoc,
}) => {
  testDocType(['collection', 'beforeChange', 'originalDoc'], originalDoc)
}
const collectionAfterChange: CollectionAfterChangeHook<IDoc> = ({
  previousDoc,
}) => {
  testDocType(['collection', 'afterChange', 'originalDoc'], previousDoc)
}

export const Doc: CollectionConfig = {
  slug: 'doc',
  hooks: {
    beforeChange: [collectionBeforeChange],
    afterChange: [collectionAfterChange],
  },
  fields: [
    {
      name: 'name',
      type: 'text',
      hooks: {
        beforeChange: [fieldBeforeChange],
        afterChange: [fieldAfterChange],
      },
    },
  ],
}

See the console output when you create or update a doc:

❌ collection   beforeChange    originalDoc
❌ field        beforeChange    previousDoc
❌ field        beforeChange    originalDoc
❌ field        afterChange     previousDoc
✔️ field        afterChange     originalDoc
❌ collection   afterChange     originalDoc

Other Details

• payload version: "^1.5.4"

I think this is partly in line with this issue #1563

Thank you for this ambitious and forward-looking project 👏

[jmikrut]

Hey @peufo — thanks for bringing this up!

Yes, it certainly does overlap with #1563. We have some big TS stuff in the works that I am VERY excited about and this will be resolved alongside that roadmap item as you expected!

In the meantime, I'm going to convert this to a discussion because this is more about improving our type accuracy rather than something explicitly broken, but we can keep the conversation going there.

How's that?