only superclass keys are encoded

[laimis17]

This is regarding chapter 7 playground MessagePackEncoder.
Where's my class info 🙂 ?

class PlaneClass: Encodable {
var manufacturer: String = "Cirrus"
var model: String = "SR22"
var seats: Int = 4
}

class Boeing: PlaneClass {
var engine: String = "ENGINE1"
}

var plane1 = Boeing()

let classencoder = MessagePackEncoder()
let data1 = try! classencoder.encode(plane1)

print(data1.map { String(format:"%02X", $0) })

Only superclass keys are encoded...
Expected Boeing class engine key to be encoded.
both playground and this code encodes same keys:

Playground(struct) code:

"encoding" CodingKeys(stringValue: "manufacturer", intValue: nil)
"encoding" CodingKeys(stringValue: "model", intValue: nil)
"encoding" CodingKeys(stringValue: "seats", intValue: nil)
["83", "A5", "73", "65", "61", "74", "73", "04", "A5", "6D", "6F", "64", "65", "6C", "A4", "53", "52", "32", "32", "AC", "6D", "61", "6E", "75", "66", "61", "63", "74", "75", "72", "65", "72", "A6", "43", "69", "72", "72", "75", "73"]

My code:

"encoding" CodingKeys(stringValue: "manufacturer", intValue: nil)
"encoding" CodingKeys(stringValue: "model", intValue: nil)
"encoding" CodingKeys(stringValue: "seats", intValue: nil)
["83", "AC", "6D", "61", "6E", "75", "66", "61", "63", "74", "75", "72", "65", "72", "A6", "43", "69", "72", "72", "75", "73", "A5", "6D", "6F", "64", "65", "6C", "A4", "53", "52", "32", "32", "A5", "73", "65", "61", "74", "73", "04"]
nil

[mattt]

@laimis17 This is a limitation of Codable synthesis, rather than a problem with MessagePackEncoder. You'll get the same behavior with JSONEncoder. See this thread for more information. I've made a note to myself to discuss this in the next update to the book.