#399

frontend/src/lib/postImportStorage.ts

@@ -1,4 +1,5 @@
 import type { PostImportOrigin,
+	      PostImportExistingPost,
 	      PostImportResetSnapshot,
 	      PostImportRow,
 	      PostImportSession,
@@ -200,6 +201,25 @@ const sanitiseResetSnapshot = (value: unknown): PostImportResetSnapshot | null =
         metadataUrl: value.metadataUrl as string | undefined }
 }
 
+const sanitiseExistingPost = (value: unknown): PostImportExistingPost | undefined => {
+    if (value == null)
+      return undefined
+    if (!(isPlainObject (value)))
+      return undefined
+    if (!(isPositiveInteger (value.id)))
+      return undefined
+    if (typeof value.title !== 'string' || typeof value.url !== 'string')
+      return undefined
+    if (value.thumbnailUrl != null && typeof value.thumbnailUrl !== 'string')
+      return undefined
+
+    return {
+        id: Number (value.id),
+        title: value.title,
+        url: value.url,
+        thumbnailUrl: value.thumbnailUrl as string | undefined }
+}
+
 
 const sanitiseRow = (value: unknown): PostImportRow | null => {
     if (!(isPlainObject (value)))
@@ -289,6 +309,7 @@ const sanitiseRow = (value: unknown): PostImportRow | null => {
         skipReason: value.skipReason ?? undefined,
         existingPostId:
             isPositiveInteger (value.existingPostId) ? Number (value.existingPostId) : undefined,
+        existingPost: sanitiseExistingPost (value.existingPost),
         metadataUrl: typeof value.metadataUrl === 'string' ? value.metadataUrl : undefined,
         resetSnapshot,
         createdPostId:
@@ -297,6 +318,26 @@ const sanitiseRow = (value: unknown): PostImportRow | null => {
         recoverable: value.recoverable === true ? true : undefined }
 }
 
+const sanitiseSession = (value: unknown): PostImportSession | null => {
+    if (!(isPlainObject (value)))
+      return null
+    if (value.version !== SESSION_VERSION || !(Array.isArray (value.rows)))
+      return null
+    if (typeof value.expiresAt !== 'string' || isExpiredSession (value.expiresAt))
+      return null
+
+    const rows = value.rows.map (sanitiseRow)
+    if (rows.some (row => row == null))
+      return null
+
+    return {
+        version: SESSION_VERSION,
+        expiresAt: value.expiresAt,
+        source: typeof value.source === 'string' ? value.source : '',
+        rows: rows as PostImportRow[],
+        repairMode: value.repairMode === 'failed' ? 'failed' : 'all' }
+}
+
 
 const isExpiredSession = (expiresAt: string): boolean => {
     const value = Date.parse (expiresAt)
@@ -332,11 +373,7 @@ export const cleanupExpiredPostImportSessions = (
 
           try
           {
-            const value = JSON.parse (raw) as { expiresAt?: string
-						rows?: unknown[] }
-            if (typeof value.expiresAt !== 'string'
-                || isExpiredSession (value.expiresAt)
-                || !(Array.isArray (value.rows)))
+            if (sanitiseSession (JSON.parse (raw)) == null)
               {
                 sessionStorage.removeItem (key)
                 --i
@@ -422,25 +459,13 @@ export const loadPostImportSession = (
 
     try
     {
-      const value = JSON.parse (raw) as Partial<PostImportSession>
-      if (value.version !== SESSION_VERSION || !(Array.isArray (value.rows)))
-        return null
-      if (typeof value.expiresAt !== 'string' || isExpiredSession (value.expiresAt))
+      const session = sanitiseSession (JSON.parse (raw))
+      if (session == null)
         {
           removeStorage (sessionKey (validatedId), onError)
           return null
         }
-
-      const rows = value.rows.map (sanitiseRow)
-      if (rows.some (row => row == null))
-        return null
-
-      return {
-          version: SESSION_VERSION,
-          expiresAt: value.expiresAt,
-          source: typeof value.source === 'string' ? value.source : '',
-          rows: rows as PostImportRow[],
-          repairMode: value.repairMode === 'failed' ? 'failed' : 'all' }
+      return session
     }
     catch
     {