fix: should allow optional properties for images option (#28709)

## Bug
- Fixes #28708

- [x] Related issues linked using `fixes #number`

packages/next/client/image.tsx

@@ -2,7 +2,7 @@ import React from 'react'
 import Head from '../shared/lib/head'
 import { toBase64 } from '../shared/lib/to-base-64'
 import {
-  ImageConfig,
+  ImageConfigComplete,
   imageConfigDefault,
   LoaderValue,
   VALID_LOADERS,
@@ -110,7 +110,8 @@ const {
   loader: configLoader,
   path: configPath,
   domains: configDomains,
-} = (process.env.__NEXT_IMAGE_OPTS as any as ImageConfig) || imageConfigDefault
+} = (process.env.__NEXT_IMAGE_OPTS as any as ImageConfigComplete) ||
+imageConfigDefault
 // sort smallest to largest
 const allSizes = [...configDeviceSizes, ...configImageSizes]
 configDeviceSizes.sort((a, b) => a - b)

packages/next/server/config-shared.ts

@@ -1,13 +1,15 @@
 import os from 'os'
 import { Header, Redirect, Rewrite } from '../lib/load-custom-routes'
-import { ImageConfig, imageConfigDefault } from './image-config'
+import {
+  ImageConfig,
+  ImageConfigComplete,
+  imageConfigDefault,
+} from './image-config'
 
-type NoOptionals<T> = {
-  [P in keyof T]-?: T[P]
+export type NextConfigComplete = Required<NextConfig> & {
+  images: ImageConfigComplete
 }
 
-export type NextConfigComplete = NoOptionals<NextConfig>
-
 export interface I18NConfig {
   defaultLocale: string
   domains?: DomainLocale[]

packages/next/server/config.ts

@@ -181,7 +181,7 @@ function assignDefaults(userConfig: { [key: string]: any }) {
   }
 
   if (result?.images) {
-    const images: Partial<ImageConfig> = result.images
+    const images: ImageConfig = result.images
 
     if (typeof images !== 'object') {
       throw new Error(

packages/next/server/image-config.ts

@@ -8,7 +8,7 @@ export const VALID_LOADERS = [
 
 export type LoaderValue = typeof VALID_LOADERS[number]
 
-export type ImageConfig = {
+export type ImageConfigComplete = {
   deviceSizes: number[]
   imageSizes: number[]
   loader: LoaderValue
@@ -18,7 +18,9 @@ export type ImageConfig = {
   minimumCacheTTL?: number
 }
 
-export const imageConfigDefault: ImageConfig = {
+export type ImageConfig = Partial<ImageConfigComplete>
+
+export const imageConfigDefault: ImageConfigComplete = {
   deviceSizes: [640, 750, 828, 1080, 1200, 1920, 2048, 3840],
   imageSizes: [16, 32, 48, 64, 96, 128, 256, 384],
   path: '/_next/image',