Enum Codable Bug

Using Swift
3

To add to what @ole says, what's happening here is not a bug, but is indeed subtly misleading:

  • Enums actually do not currently synthesize Codable conformance — see Automatic Codable conformance for enums with associated values that themselves conform to Codable for a bit of background, but at the moment, there's no decided-upon representation of what encoded enums should look like; as such, no implementation is offered
  • The reason you are getting a default implementation of Codable is because Options is RawRepresentable with a RawValue of String. RawRepresentable types whose RawValue is a Codable primitive type (Int, UInt, Double, String, etc.) get a default implementation based on that RawValue; you can see the one for String
  • As @ole says, these RawRepresentable implementations encode and decode in terms of the underlying rawValue, and do so in and out of a single-value encoding/decoding container. That's why your keys aren't used

So indeed, you can either assign the raw values of the enum cases to match the representation you want (if feasible), or keep the values the same but provide your own Codable implementation to override the default.

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