feat: make req partial and optional in DB / Local API operations

[r1tsuu]

What?

Previously, the req argument:
In database operations (e.g payload.db) was required and you needed to pass the whole req with all the properties. This is confusing because in database operations we never use its properties outside of req.transactionID and req.t, both of which should be optional as well.

Now, you don't have to do that cast:

payload.db.findOne({
  collection: 'posts',
  req: {} as PayloadRequest,
  where: {
    id: {
      equals: 1,
    },
  },
})

Becomes:

payload.db.findOne({
  collection: 'posts',
  where: {
    id: {
      equals: 1,
    },
  },
})

If you need to use transactions, you're not required to do the as cast as well now, as the req not only optional but also partial - Partial<PayloadRequest>.
initTransaction, commitTransaction, killTransaction utilities are typed better now as well. They do not require to you pass all the properties of req, but only payload - MarkRequired<Partial<PayloadRequest>, 'payload'>

const req = { payload }
await initTransaction(req)
await payload.db.create({
  collection: "posts",
  data: {},
  req
})
await commitTransaction(req)

The same for the Local API. Internal operations (for example packages/payload/src/collections/operations/find.ts) still accept the whole req, but local ones (packages/payload/src/collections/operations/local/find.ts) which are used through payload. now accept Partial<PayloadRequest>, as they pass it through to internal operations with createLocalReq.

So now, this is also valid, while previously you had to do as cast for req.

const req = { payload }
await initTransaction(req)
await payload.create({
  collection: "posts",
  data: {},
  req
})
await commitTransaction(req)

Marked as deprecated PayloadRequest['transactionIDPromise'] to remove in the next major version. It was never used anywhere.
Refactored withSession that returns an object to getSession that returns just ClientSession. Better type safety for arguments
Deduplicated in all drizzle operations to getTransaction(this, req) utility:

const db = this.sessions[await req?.transactionID]?.db || this.drizzle

Added fallback for throwing unique validation errors in database operations when req.t is not available.

In migration up and down functions our req is not partial, while we used to passed req with only 2 properties - payload and transactionID. This is misleading and you can't access for example req.t.
Now, to achieve "real" full req - we generate it with createLocalReq in all migration functions.

This all is backwards compatible. In all public API places where you expect the full req (like hooks) you still have it.

Why?

Better DX, more expected types, less errors because of types casting.

[DanRibbens]

Nice changes!

[github-actions]

🚀 This is included in version v3.10.0