frontend/src/components/PostEditForm.tsx

@@ -79,7 +79,7 @@ const PostEditForm: FC<Props> = ({ post, onSave }) => {
 
       if (response?.status !== 409)
 	{
-	  const validationError = extractValidationError (e)
+	  const validationError = extractValidationError<PostFormField> (e)
 
 	  if (validationError)
 	    {
@@ -145,6 +145,8 @@ const PostEditForm: FC<Props> = ({ post, onSave }) => {
 
   return (
       <form onSubmit={handleSubmit} className="max-w-xl pt-2 space-y-4">
+	<FieldError messages={baseErrors}/>
+
 	{/* タイトル */}
 	<div>
 	  <Label>タイトル</Label>
@@ -166,7 +168,7 @@ const PostEditForm: FC<Props> = ({ post, onSave }) => {
 	      disabled={disabled}
 	      value={parentPostIds}
 	      onChange={e => setParentPostIds (e.target.value)}
-	      alia-invalid={fieldErrors.parentPostIds && fieldErrors.parentPostIds.length > 0}
+	      aria-invalid={fieldErrors.parentPostIds && fieldErrors.parentPostIds.length > 0}
 	      className={inputClass (fieldErrors.parentPostIds
 				     && fieldErrors.parentPostIds.length > 0)}/>
 	  <FieldError messages={fieldErrors.parentPostIds}/>
@@ -189,9 +191,7 @@ const PostEditForm: FC<Props> = ({ post, onSave }) => {
 	    errors={fieldErrors.originalCreatedAt}/>
 
 	{/* 送信 */}
-	<Button
-	    type="submit"
-	    disabled={disabled}>
+	<Button type="submit" disabled={disabled}>
 	  更新
 	</Button>
       </form>)

frontend/src/components/common/FieldError.tsx

@@ -4,7 +4,7 @@ type Props = { messages?: string[] }
 
 
 export const FieldError: FC<Props> = ({ messages }: Props) => {
-  if (!(messages?.length))
+  if (!(messages) || messages.length === 0)
     return null
 
   return (

frontend/src/lib/apiErrors.ts

@@ -2,11 +2,12 @@ import toCamel from 'camelcase-keys'
 
 import { isApiError } from '@/lib/api'
 
-export type FieldErrors = Partial<Record<string, string[]>>
+export type FieldErrors<T extends string = string> = Partial<Record<T, string[]>>
 
-export type ValidationError = { message:      string
-				fieldErrors:  FieldErrors
-				baseErrors:   string[] }
+export type ValidationError<T extends string = string> =
+    { message:      string
+      fieldErrors:  FieldErrors<T>
+      baseErrors:   string[] }
 
 type RawValidationError = { type?:        string
 			    message?:     string
@@ -14,7 +15,7 @@ type RawValidationError = { type?:        string
 			    baseErrors?:  string[] }
 
 
-export const extractValidationError = (err: unknown) => {
+export const extractValidationError = <T extends string = string> (err: unknown) => {
   if (!(isApiError (err)) || err.response?.status !== 422)
     return null
 
@@ -25,6 +26,6 @@ export const extractValidationError = (err: unknown) => {
     return null
 
   return { message: data.message ?? '入力内容を確認してください．',
-	   fieldErrors: (data.errors ?? { }) as FieldErrors,
+	   fieldErrors: (data.errors ?? { }) as FieldErrors<T>,
 	   baseErrors: data.baseErrors ?? [] }
 }