fix: harden danbooru decoding and pagination flow

1 files changed, 22 insertions, 2 deletions

diff --git a/Sora/Data/Danbooru/DanbooruPostParser.swift b/Sora/Data/Danbooru/DanbooruPostParser.swift
index f990ed5..1e5cdc4 100644
--- a/Sora/Data/Danbooru/DanbooruPostParser.swift
+++ b/Sora/Data/Danbooru/DanbooruPostParser.swift
@@ -1,6 +1,16 @@
 import Foundation
 
 nonisolated class DanbooruPostParser {
+  private struct FailableDecodable<Value: Decodable>: Decodable {
+    let value: Value?
+
+    init(from decoder: Decoder) throws {
+      let container = try decoder.singleValueContainer()
+
+      value = try? container.decode(Value.self)
+    }
+  }
+
   private let data: Data
 
   init(data: Data) {
@@ -17,10 +27,20 @@ nonisolated class DanbooruPostParser {
     }
 
     do {
-      return try decoder.decode([DanbooruPost].self, from: data).compactMap { post in
-        post.toBooruPost()
+      let decodedPosts = try decoder.decode([FailableDecodable<DanbooruPost>].self, from: data)
+      let validPosts = decodedPosts.compactMap(\.value)
+      let droppedRecordCount = decodedPosts.count - validPosts.count
+
+      if droppedRecordCount > 0 {
+        debugPrint(
+          "DanbooruPostParser.parse: dropped \(droppedRecordCount) malformed records while decoding page."
+        )
       }
+
+      return validPosts.compactMap { post in post.toBooruPost() }
     } catch {
+      debugPrint("DanbooruPostParser.parse: failed to decode response: \(error)")
+
       return []
     }
   }