[dev-overlay] Remove unused code when handling hydration mismatches

Author: eps1lon

packages/next/src/client/components/errors/attach-hydration-error-state.ts

@@ -1,11 +1,11 @@
 import {
-  getDefaultHydrationErrorMessage,
   isHydrationError,
   testReactHydrationWarning,
 } from '../is-hydration-error'
 import {
   hydrationErrorState,
   getReactHydrationDiffSegments,
+  type HydrationErrorState,
 } from './hydration-error-info'
 
 export function attachHydrationErrorState(error: Error) {
@@ -27,15 +27,14 @@ export function attachHydrationErrorState(error: Error) {
   if (reactHydrationDiffSegments) {
     const diff = reactHydrationDiffSegments[1]
     parsedHydrationErrorState = {
-      ...(error as any).details,
+      ...((error as any).details as HydrationErrorState),
       ...hydrationErrorState,
       // If diff is present in error, we don't need to pick up the console logged warning.
       // - if hydration error has diff, and is not hydration diff log, then it's a normal hydration error.
       // - if hydration error no diff, then leverage the one from the hydration diff log.
 
-      warning: (diff && !isHydrationWarning
-        ? null
-        : hydrationErrorState.warning) || [getDefaultHydrationErrorMessage()],
+      warning:
+        diff && !isHydrationWarning ? undefined : hydrationErrorState.warning,
       // When it's hydration diff log, do not show notes section.
       // This condition is only for the 1st squashed error.
       notes: isHydrationWarning ? '' : reactHydrationDiffSegments[0],

packages/next/src/client/components/is-hydration-error.ts

@@ -15,10 +15,6 @@ export const REACT_HYDRATION_ERROR_LINK =
 export const NEXTJS_HYDRATION_ERROR_LINK =
   'https://nextjs.org/docs/messages/react-hydration-error'
 
-export const getDefaultHydrationErrorMessage = () => {
-  return reactUnifiedMismatchWarning
-}
-
 export function isHydrationError(error: unknown): boolean {
   return isError(error) && hydrationErrorRegex.test(error.message)
 }