Decode meta_data incorrectly sent as an object (#16141)

Author: joshheald

Modules/Sources/Networking/Model/Product/Product.swift

@@ -457,7 +457,7 @@ public struct Product: Codable, GeneratedCopiable, Equatable, GeneratedFakeable
                                                                     // `true`
                                                                     value.lowercased() == Values.manageStockParent ? true : false
                                                                 })
-        ]) ?? false
+                                                            ]) ?? false
 
         // Even though WooCommerce Core returns Int or null values,
         // some plugins alter the field value from Int to Decimal or String.
@@ -535,15 +535,17 @@ public struct Product: Codable, GeneratedCopiable, Equatable, GeneratedFakeable
         let menuOrder = try container.decode(Int.self, forKey: .menuOrder)
 
         // Filter out metadata if the key is prefixed with an underscore (internal meta keys)
-        let customFields = (try? container.decode([MetaData].self, forKey: .metadata).filter({ !$0.key.hasPrefix("_")})) ?? []
+        // Support both array format and object keyed by index strings
+        let allMetaData = [MetaData].decodeFlexibly(from: container, forKey: .metadata)
+        let customFields = allMetaData.filter { !$0.key.hasPrefix("_") }
 
         // In some isolated cases, it appears to be some malformed meta-data that causes this line to throw hence the whole product decoding to throw.
         // Since add-ons are optional, `try?` will be used to prevent the whole decoding to stop.
         // https://github.com/woocommerce/woocommerce-ios/issues/4205
         let addOns = (try? container.decodeIfPresent(ProductAddOnEnvelope.self, forKey: .metadata)?.revolve()) ?? []
 
-        let metaDataExtractor = try? container.decodeIfPresent(ProductMetadataExtractor.self, forKey: .metadata)
-        let isSampleItem = (metaDataExtractor?.extractStringValue(forKey: MetadataKeys.headStartPost) == Values.headStartValue)
+        let metaDataExtractor = ProductMetadataExtractor(metadata: allMetaData)
+        let isSampleItem = (metaDataExtractor.extractStringValue(forKey: MetadataKeys.headStartPost) == Values.headStartValue)
 
         // Product Bundle properties
         // Uses failsafe decoding because non-bundle product types can return unexpected value types.
@@ -561,7 +563,7 @@ public struct Product: Codable, GeneratedCopiable, Equatable, GeneratedFakeable
         let compositeComponents = try container.decodeIfPresent([ProductCompositeComponent].self, forKey: .compositeComponents) ?? []
 
         // Subscription properties
-        let subscription = try? metaDataExtractor?.extractProductSubscription()
+        let subscription = try? metaDataExtractor.extractProductSubscription()
 
         // Min/Max Quantities properties
         let minAllowedQuantity = container.failsafeDecodeIfPresent(stringForKey: .minAllowedQuantity)

Modules/Sources/Networking/Model/Product/ProductMetadataExtractor.swift

@@ -1,5 +1,6 @@
 import Foundation
 import WordPressShared
+import NetworkingCore
 
 /// Helper to extract specific data from inside `Product` metadata.
 /// Sample Json:
@@ -21,25 +22,23 @@ import WordPressShared
 /// }
 /// ]
 ///
-internal struct ProductMetadataExtractor: Decodable {
+struct ProductMetadataExtractor {
 
-    private typealias DecodableDictionary = [String: AnyDecodable]
     private typealias AnyDictionary = [String: Any?]
 
     /// Internal metadata representation
     ///
-    private let metadata: [DecodableDictionary]
+    private let metadata: [MetaData]
 
-    /// Decode main metadata array as an untyped dictionary.
+    /// Initialize with already-decoded metadata array
     ///
-    init(from decoder: Decoder) throws {
-        let container = try decoder.singleValueContainer()
-        self.metadata = try container.decode([DecodableDictionary].self)
+    init(metadata: [MetaData]) {
+        self.metadata = metadata
     }
 
     /// Searches product metadata for subscription data and converts it to a `ProductSubscription` if possible.
     ///
-    internal func extractProductSubscription() throws -> ProductSubscription? {
+    func extractProductSubscription() throws -> ProductSubscription? {
         let subscriptionMetadata = filterMetadata(with: Constants.subscriptionPrefix)
 
         guard !subscriptionMetadata.isEmpty else {
@@ -54,30 +53,33 @@ internal struct ProductMetadataExtractor: Decodable {
 
     /// Extracts a `String` metadata value for the provided key.
     ///
-    internal func extractStringValue(forKey key: String) -> String? {
+    func extractStringValue(forKey key: String) -> String? {
         let metaData = filterMetadata(with: key)
         let keyValueMetadata = getKeyValueDictionary(from: metaData)
         return keyValueMetadata.valueAsString(forKey: key)
     }
 
     /// Filters product metadata using the provided prefix.
     ///
-    private func filterMetadata(with prefix: String) -> [DecodableDictionary] {
-        metadata.filter { object in
-            let objectKey = object["key"]?.value as? String ?? ""
-            return objectKey.hasPrefix(prefix)
-        }
+    private func filterMetadata(with prefix: String) -> [MetaData] {
+        metadata.filter { $0.key.hasPrefix(prefix) }
     }
 
     /// Parses provided metadata to return a dictionary with each metadata object's key and value.
     ///
-    private func getKeyValueDictionary(from metadata: [DecodableDictionary]) -> AnyDictionary {
-        metadata.reduce(AnyDictionary()) { (dict, object) in
-            var newDict = dict
-            let objectKey = object["key"]?.value as? String ?? ""
-            let objectValue = object["value"]?.value
-            newDict.updateValue(objectValue, forKey: objectKey)
-            return newDict
+    private func getKeyValueDictionary(from metadata: [MetaData]) -> AnyDictionary {
+        metadata.reduce(into: AnyDictionary()) { dict, object in
+            // For JSON values, decode them to get the actual object
+            if object.value.isJson {
+                if let data = object.value.stringValue.data(using: .utf8),
+                   let jsonObject = try? JSONSerialization.jsonObject(with: data, options: []) {
+                    dict[object.key] = jsonObject
+                } else {
+                    dict[object.key] = object.value.stringValue
+                }
+            } else {
+                dict[object.key] = object.value.stringValue
+            }
         }
     }
 

Modules/Sources/Networking/Model/Product/ProductVariation.swift

@@ -279,7 +279,7 @@ public struct ProductVariation: Codable, GeneratedCopiable, Equatable, Generated
                                                                     }
                                                                     return false
                                                                 })
-        ]) ?? false
+                                                            ]) ?? false
 
         // Even though WooCommerce Core returns Int or null values,
         // some plugins alter the field value from Int to Decimal or String.
@@ -309,7 +309,9 @@ public struct ProductVariation: Codable, GeneratedCopiable, Equatable, Generated
         let menuOrder = try container.decode(Int64.self, forKey: .menuOrder)
 
         // Subscription settings for subscription variations
-        let subscription = try? container.decodeIfPresent(ProductMetadataExtractor.self, forKey: .metadata)?.extractProductSubscription()
+        let allMetaData = [MetaData].decodeFlexibly(from: container, forKey: .metadata)
+        let metaDataExtractor = ProductMetadataExtractor(metadata: allMetaData)
+        let subscription = try? metaDataExtractor.extractProductSubscription()
 
         // Min/Max Quantities properties
         let minAllowedQuantity = container.failsafeDecodeIfPresent(stringForKey: .minAllowedQuantity)

Modules/Sources/NetworkingCore/Model/MetaDataArray+FlexibleDecoding.swift

@@ -0,0 +1,24 @@
+import Foundation
+
+/// Extension to support flexible decoding of MetaData arrays
+/// Handles both standard array format and object format keyed by index strings
+extension Array where Element == MetaData {
+
+    /// Custom decoding from container that supports both array and dictionary formats
+    public static func decodeFlexibly<K>(from container: KeyedDecodingContainer<K>,
+                                         forKey key: KeyedDecodingContainer<K>.Key) -> [MetaData] {
+        // Try to decode as array first (standard format)
+        if let metaDataArray = try? container.decode([MetaData].self, forKey: key) {
+            return metaDataArray
+        }
+
+        // Try to decode as object keyed by index strings
+        if let metaDataDict = try? container.decode([String: MetaData].self, forKey: key) {
+            return Array(metaDataDict.values)
+        }
+
+        // Fallback to empty array
+        DDLogWarn("⚠️ Could not decode metadata as either an array or object keyed by index strings. Falling back to empty array.")
+        return []
+    }
+}

Modules/Sources/NetworkingCore/Model/Order.swift

@@ -201,7 +201,10 @@ public struct Order: Decodable, Sendable, GeneratedCopiable, GeneratedFakeable {
         // "payment_url" is only available on stores with version >= 6.4
         let paymentURL = try container.decodeIfPresent(URL.self, forKey: .paymentURL)
 
-        let allOrderMetaData = try? container.decode([MetaData].self, forKey: .metadata)
+        let allOrderMetaData: [MetaData]? = {
+            let metadata = [MetaData].decodeFlexibly(from: container, forKey: .metadata)
+            return metadata.isEmpty ? nil : metadata
+        }()
         var chargeID: String? = nil
         chargeID = allOrderMetaData?.first(where: { $0.key == "_charge_id" })?.value.stringValue
 

Modules/Tests/NetworkingTests/Mapper/MetaDataMapperTests.swift

@@ -49,6 +49,136 @@ final class MetaDataMapperTests: XCTestCase {
         XCTAssertEqual(metadata[5], MetaData(metadataID: 6, key: "number_field", value: "42"))
         XCTAssertEqual(metadata[6], MetaData(metadataID: 7, key: "empty_field", value: ""))
     }
+
+    /// Tests that flexible metadata decoding works with array format in a realistic context
+    ///
+    func test_flexible_metadata_decoding_array_format() throws {
+        // Given - JSON with metadata as array in a product-like structure
+        let jsonString = """
+        {
+            "id": 123,
+            "name": "Test Product",
+            "meta_data": [
+                {
+                    "id": 1001,
+                    "key": "custom_field_1",
+                    "value": "value1"
+                },
+                {
+                    "id": 1002,
+                    "key": "_internal_field",
+                    "value": "internal_value"
+                },
+                {
+                    "id": 1003,
+                    "key": "custom_field_2",
+                    "value": "value2"
+                }
+            ]
+        }
+        """
+
+        struct TestProduct: Decodable {
+            let id: Int
+            let name: String
+            let metadata: [MetaData]
+
+            private enum CodingKeys: String, CodingKey {
+                case id, name
+                case metadata = "meta_data"
+            }
+
+            init(from decoder: Decoder) throws {
+                let container = try decoder.container(keyedBy: CodingKeys.self)
+                self.id = try container.decode(Int.self, forKey: .id)
+                self.name = try container.decode(String.self, forKey: .name)
+
+                // Flexible decoding logic using helper
+                self.metadata = [MetaData].decodeFlexibly(from: container, forKey: .metadata)
+            }
+        }
+
+        let data = jsonString.data(using: .utf8)!
+        let decoder = JSONDecoder()
+
+        // When
+        let product = try decoder.decode(TestProduct.self, from: data)
+
+        // Then
+        XCTAssertEqual(product.metadata.count, 3) // All fields should be present
+        XCTAssertEqual(product.metadata[0].metadataID, 1001)
+        XCTAssertEqual(product.metadata[0].key, "custom_field_1")
+        XCTAssertEqual(product.metadata[0].value.stringValue, "value1")
+        XCTAssertEqual(product.metadata[1].metadataID, 1002)
+        XCTAssertEqual(product.metadata[1].key, "_internal_field")
+        XCTAssertEqual(product.metadata[1].value.stringValue, "internal_value")
+        XCTAssertEqual(product.metadata[2].metadataID, 1003)
+        XCTAssertEqual(product.metadata[2].key, "custom_field_2")
+        XCTAssertEqual(product.metadata[2].value.stringValue, "value2")
+    }
+
+    /// Tests that flexible metadata decoding works with dictionary format in a realistic context
+    ///
+    func test_flexible_metadata_decoding_dictionary_format() throws {
+        // Given - JSON with metadata as object keyed by index strings in a product-like structure
+        let jsonString = """
+        {
+            "id": 456,
+            "name": "Test Product 2",
+            "meta_data": {
+                "0": {
+                    "id": 2001,
+                    "key": "dict_field_1",
+                    "value": "dict_value1"
+                },
+                "1": {
+                    "id": 2002,
+                    "key": "_internal_dict_field",
+                    "value": "internal_dict_value"
+                },
+                "2": {
+                    "id": 2003,
+                    "key": "dict_field_2",
+                    "value": "dict_value2"
+                }
+            }
+        }
+        """
+
+        struct TestProduct: Decodable {
+            let id: Int
+            let name: String
+            let metadata: [MetaData]
+
+            private enum CodingKeys: String, CodingKey {
+                case id, name
+                case metadata = "meta_data"
+            }
+
+            init(from decoder: Decoder) throws {
+                let container = try decoder.container(keyedBy: CodingKeys.self)
+                self.id = try container.decode(Int.self, forKey: .id)
+                self.name = try container.decode(String.self, forKey: .name)
+
+                // Flexible decoding logic using helper
+                self.metadata = [MetaData].decodeFlexibly(from: container, forKey: .metadata)
+            }
+        }
+
+        let data = jsonString.data(using: .utf8)!
+        let decoder = JSONDecoder()
+
+        // When
+        let product = try decoder.decode(TestProduct.self, from: data)
+
+        // Then
+        XCTAssertEqual(product.metadata.count, 3) // All fields should be present
+        let fieldNames = Set(product.metadata.map { $0.key })
+        XCTAssertTrue(fieldNames.contains("dict_field_1"))
+        XCTAssertTrue(fieldNames.contains("dict_field_2"))
+        XCTAssertTrue(fieldNames.contains("_internal_dict_field"))
+    }
+
 }
 
 // MARK: - Test Helpers