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JSONDecoder enum-keyed dictionary bug
Hello everyone, I think I've discovered a bug in JSONDecoder and I'd like to get a quick sanity-check on this, as well as hopefully some ideas to work around the issue. When attempting to decode a Decodable struct from JSON using JSONDecoder, the decoder throws an error when it encounters a dictionary that is keyed by an enum and somehow seems to think that the enum is an Array<Any>. Here's a minimal reproducible example: let jsonString = """ { "variations": { "plural": "tests", "singular": "test" } } """ struct Json: Codable { let variations: [VariationKind: String] } enum VariationKind: String, Codable, Hashable { case plural = "plural" case singular = "singular" } and then the actual decoding: let json = try JSONDecoder().decode( Json.self, from: jsonString.data(using: .utf8)! ) print(json) The expected result would of course be the following: Json( variations: [ VariationKind.plural: "tests", VariationKind.singular: "test" ] ) But the actual result is an error: Swift.DecodingError.typeMismatch( Swift.Array<Any>, Swift.DecodingError.Context( codingPath: [ CodingKeys(stringValue: "variations", intValue: nil) ], debugDescription: "Expected to decode Array<Any> but found a dictionary instead.", underlyingError: nil ) ) So basically, the JSONDecoder tries to decode Swift.Array<Any> but encounters a dictionary (duh), and I have no idea why this is happening. There are literally no arrays anywhere, neither in the actual JSON string, nor in any of the Codable structs. Curiously, if I change the dictionary from [VariationKind: String] to [String: String], everything works perfectly. So something about the enum seems to cause confusion in JSONDecoder. I've tried to fix this by implementing Decodable myself for VariationKind and using a singleValueContainer, but that causes exactly the same error. Am I crazy, or is that a bug?
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Jun ’25
iOS 18 SwiftData ModelContext reset
Since the iOS 18 and Xcode 16, I've been getting some really strange SwiftData errors when passing @Model classes around. The error I'm seeing is the following: SwiftData/BackingData.swift:409: Fatal error: This model instance was destroyed by calling ModelContext.reset and is no longer usable. PersistentIdentifier(id: SwiftData.PersistentIdentifier.ID(url: x-coredata://34EE9059-A7B5-4484-96A0-D10786AC9FB0/TestApp/p2), implementation: SwiftData.PersistentIdentifierImplementation) The same issue also happens when I try to retrieve a model from the ModelContext using its PersistentIdentifier and try to do anything with it. I have no idea what could be causing this. I'm guessing this is just a bug in the iOS 18 Beta, since I couldn't find a single discussion about this on Google, I figured I'd mention it. if someone has a workaround or something, that would be much appreciated.
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Jun ’24