feat: expose req to defaultValue function arguments (#9937)

Rework of https://github.com/payloadcms/payload/pull/5912

### What?
Now, when `defaultValue` is defined as function you can receive the
`req` argument:
```ts
{
  name: 'defaultValueFromReq',
  type: 'text',
  defaultValue: async ({ req, user, locale }) => {
    return Promise.resolve(req.context.defaultValue)
  },
},
```

`user` and `locale` even though are repeated in `req`, this potentially
leaves some room to add more args in the future without removing them
now.
This also improves type for `defaultValue`:
```ts
type SerializableValue = boolean | number | object | string
export type DefaultValue =
  | ((args: {
      locale?: TypedLocale
      req: PayloadRequest
      user: PayloadRequest['user']
    }) => SerializableValue)
  | SerializableValue
```

### Why?
To access the current URL / search params / Local API and other things
directly in `defaultValue`.

### How?
Passes `req` through everywhere where we call `defaultValue()`

docs/fields/overview.mdx

@@ -212,6 +212,7 @@ Functions can be written to make use of the following argument properties:
 
 - `user` - the authenticated user object
 - `locale` - the currently selected locale string
+- `req` - the `PayloadRequest` object
 
 Here is an example of a `defaultValue` function:
 
@@ -227,7 +228,7 @@ export const myField: Field = {
   name: 'attribution',
   type: 'text',
   // highlight-start
-  defaultValue: ({ user, locale }) =>
+  defaultValue: ({ user, locale, req }) =>
     `${translation[locale]} ${user.name}`,
   // highlight-end
 }
@@ -235,7 +236,7 @@ export const myField: Field = {
 
 <Banner type="success">
   <strong>Tip:</strong>
-  You can use async `defaultValue` functions to fill fields with data from API requests.
+  You can use async `defaultValue` functions to fill fields with data from API requests or Local API using `req.payload`.
 </Banner>
 
 ### Validation

packages/payload/src/fields/config/types.ts

@@ -127,7 +127,7 @@ import type {
   TextareaFieldValidation,
 } from '../../index.js'
 import type { DocumentPreferences } from '../../preferences/types.js'
-import type { Operation, PayloadRequest, Where } from '../../types/index.js'
+import type { DefaultValue, Operation, PayloadRequest, Where } from '../../types/index.js'
 import type {
   NumberFieldManyValidation,
   NumberFieldSingleValidation,
@@ -395,7 +395,7 @@ export interface FieldBase {
   admin?: Admin
   /** Extension point to add your custom data. Server only. */
   custom?: Record<string, any>
-  defaultValue?: any
+  defaultValue?: DefaultValue
   hidden?: boolean
   hooks?: {
     afterChange?: FieldHook[]
@@ -1338,7 +1338,7 @@ export type BlocksField = {
     isSortable?: boolean
   } & Admin
   blocks: Block[]
-  defaultValue?: unknown
+  defaultValue?: DefaultValue
   labels?: Labels
   maxRows?: number
   minRows?: number

packages/payload/src/fields/getDefaultValue.ts

@@ -1,10 +1,11 @@
-import type { JsonValue, PayloadRequest } from '../types/index.js'
+import type { DefaultValue, JsonValue, PayloadRequest } from '../types/index.js'
 
 import { deepCopyObjectSimple } from '../utilities/deepCopyObject.js'
 
 type Args = {
-  defaultValue: ((args: any) => JsonValue) | any
+  defaultValue: DefaultValue
   locale: string | undefined
+  req: PayloadRequest
   user: PayloadRequest['user']
   value?: JsonValue
 }
@@ -12,6 +13,7 @@ type Args = {
 export const getDefaultValue = async ({
   defaultValue,
   locale,
+  req,
   user,
   value,
 }: Args): Promise<JsonValue> => {
@@ -20,7 +22,7 @@ export const getDefaultValue = async ({
   }
 
   if (defaultValue && typeof defaultValue === 'function') {
-    return await defaultValue({ locale, user })
+    return await defaultValue({ locale, req, user })
   }
 
   if (typeof defaultValue === 'object') {

packages/payload/src/fields/hooks/afterRead/promise.ts

@@ -322,6 +322,7 @@ export const promise = async ({
       siblingDoc[field.name] = await getDefaultValue({
         defaultValue: field.defaultValue,
         locale,
+        req,
         user: req.user,
         value: siblingDoc[field.name],
       })

packages/payload/src/fields/hooks/beforeValidate/promise.ts

@@ -316,6 +316,7 @@ export const promise = async <T>({
         siblingData[field.name] = await getDefaultValue({
           defaultValue: field.defaultValue,
           locale: req.locale,
+          req,
           user: req.user,
           value: siblingData[field.name],
         })

packages/payload/src/types/index.ts

@@ -121,6 +121,15 @@ export type Where = {
 
 export type Sort = Array<string> | string
 
+type SerializableValue = boolean | number | object | string
+export type DefaultValue =
+  | ((args: {
+      locale?: TypedLocale
+      req: PayloadRequest
+      user: PayloadRequest['user']
+    }) => SerializableValue)
+  | SerializableValue
+
 /**
  * Applies pagination for join fields for including collection relationships
  */

packages/ui/src/forms/fieldSchemasToFormState/calculateDefaultValues/index.ts

@@ -1,4 +1,4 @@
-import type { Data, Field as FieldSchema, User } from 'payload'
+import type { Data, Field as FieldSchema, PayloadRequest, User } from 'payload'
 
 import { iterateFields } from './iterateFields.js'
 
@@ -7,6 +7,7 @@ type Args = {
   fields: FieldSchema[]
   id?: number | string
   locale: string | undefined
+  req: PayloadRequest
   siblingData: Data
   user: User
 }
@@ -16,6 +17,7 @@ export const calculateDefaultValues = async ({
   data,
   fields,
   locale,
+  req,
   user,
 }: Args): Promise<Data> => {
   await iterateFields({
@@ -23,6 +25,7 @@ export const calculateDefaultValues = async ({
     data,
     fields,
     locale,
+    req,
     siblingData: data,
     user,
   })

packages/ui/src/forms/fieldSchemasToFormState/calculateDefaultValues/iterateFields.ts

@@ -1,4 +1,4 @@
-import type { Data, Field, TabAsField, User } from 'payload'
+import type { Data, Field, PayloadRequest, TabAsField, User } from 'payload'
 
 import { defaultValuePromise } from './promise.js'
 
@@ -7,6 +7,7 @@ type Args<T> = {
   fields: (Field | TabAsField)[]
   id?: number | string
   locale: string | undefined
+  req: PayloadRequest
   siblingData: Data
   user: User
 }
@@ -16,6 +17,7 @@ export const iterateFields = async <T>({
   data,
   fields,
   locale,
+  req,
   siblingData,
   user,
 }: Args<T>): Promise<void> => {
@@ -28,6 +30,7 @@ export const iterateFields = async <T>({
         data,
         field,
         locale,
+        req,
         siblingData,
         user,
       }),

packages/ui/src/forms/fieldSchemasToFormState/calculateDefaultValues/promise.ts

@@ -1,4 +1,4 @@
-import type { Data, Field, TabAsField, User } from 'payload'
+import type { Data, Field, PayloadRequest, TabAsField, User } from 'payload'
 
 import { getDefaultValue } from 'payload'
 import { fieldAffectsData, tabHasName } from 'payload/shared'
@@ -10,6 +10,7 @@ type Args<T> = {
   field: Field | TabAsField
   id?: number | string
   locale: string | undefined
+  req: PayloadRequest
   siblingData: Data
   user: User
 }
@@ -20,6 +21,7 @@ export const defaultValuePromise = async <T>({
   data,
   field,
   locale,
+  req,
   siblingData,
   user,
 }: Args<T>): Promise<void> => {
@@ -31,6 +33,7 @@ export const defaultValuePromise = async <T>({
       siblingData[field.name] = await getDefaultValue({
         defaultValue: field.defaultValue,
         locale,
+        req,
         user,
         value: siblingData[field.name],
       })
@@ -52,6 +55,7 @@ export const defaultValuePromise = async <T>({
               data,
               fields: field.fields,
               locale,
+              req,
               siblingData: row,
               user,
             }),
@@ -81,6 +85,7 @@ export const defaultValuePromise = async <T>({
                 data,
                 fields: block.fields,
                 locale,
+                req,
                 siblingData: row,
                 user,
               }),
@@ -94,13 +99,13 @@ export const defaultValuePromise = async <T>({
     }
 
     case 'collapsible':
-
     case 'row': {
       await iterateFields({
         id,
         data,
         fields: field.fields,
         locale,
+        req,
         siblingData,
         user,
       })
@@ -119,6 +124,7 @@ export const defaultValuePromise = async <T>({
         data,
         fields: field.fields,
         locale,
+        req,
         siblingData: groupData,
         user,
       })
@@ -143,6 +149,7 @@ export const defaultValuePromise = async <T>({
         data,
         fields: field.fields,
         locale,
+        req,
         siblingData: tabSiblingData,
         user,
       })
@@ -156,6 +163,7 @@ export const defaultValuePromise = async <T>({
         data,
         fields: field.tabs.map((tab) => ({ ...tab, type: 'tab' })),
         locale,
+        req,
         siblingData,
         user,
       })

packages/ui/src/forms/fieldSchemasToFormState/index.tsx

@@ -84,6 +84,7 @@ export const fieldSchemasToFormState = async (args: Args): Promise<FormState> =>
       data: dataWithDefaultValues,
       fields,
       locale: req.locale,
+      req,
       siblingData: dataWithDefaultValues,
       user: req.user,
     })

test/fields/collections/Text/index.ts

@@ -151,6 +151,13 @@ const TextFields: CollectionConfig = {
       hasMany: true,
       maxRows: 4,
     },
+    {
+      name: 'defaultValueFromReq',
+      type: 'text',
+      defaultValue: async ({ req }) => {
+        return Promise.resolve(req.context.defaultValue)
+      },
+    },
     {
       name: 'disableListColumnText',
       type: 'text',

test/fields/int.spec.ts

@@ -97,6 +97,20 @@ describe('Fields', () => {
       expect(fieldWithDefaultValue).toEqual(dependentOnFieldWithDefaultValue)
     })
 
+    it('should populate function default values from req', async () => {
+      const text = await payload.create({
+        req: {
+          context: {
+            defaultValue: 'from-context',
+          },
+        },
+        collection: 'text-fields',
+        data: { text: 'required' },
+      })
+
+      expect(text.defaultValueFromReq).toBe('from-context')
+    })
+
     it('should localize an array of strings using hasMany', async () => {
       const localizedHasMany = ['hello', 'world']
       const { id } = await payload.create({

test/fields/payload-types.ts

@@ -783,6 +783,7 @@ export interface TextField {
   localizedHasMany?: string[] | null;
   withMinRows?: string[] | null;
   withMaxRows?: string[] | null;
+  defaultValueFromReq?: string | null;
   disableListColumnText?: string | null;
   disableListFilterText?: string | null;
   array?:
@@ -2997,6 +2998,7 @@ export interface TextFieldsSelect<T extends boolean = true> {
   localizedHasMany?: T;
   withMinRows?: T;
   withMaxRows?: T;
+  defaultValueFromReq?: T;
   disableListColumnText?: T;
   disableListFilterText?: T;
   array?: