ResultCodable.swift

public struct ResultCodable<CodableType>: Codable where CodableType: Codable {

    private enum EncodingError: Swift.Error, CustomStringConvertible {
        case encodedErrorResult(encodingError: Swift.Error)
        
        var description: String {
            switch self {
            case .encodedErrorResult(let encodingError):
                return "Cannot encode `Result.failure` which resulted from decoding error: '\(encodingError)'"
            }
        }
    }
    
    public let result: Result<CodableType, Swift.Error>
    
    public init(value: CodableType) {
        self.result = .success(value)
    }
    
    public init(from decoder: Decoder) throws {
        let container = try decoder.singleValueContainer()
        do {
            self.result = try .success(container.decode(CodableType.self))
        } catch {
            self.result = .failure(error)
        }
    }
    
    public func encode(to encoder: Encoder) throws {
        var container = encoder.singleValueContainer()
        switch result {
        case .success(let value):
            try container.encode(value)
        case .failure(let error):
            assertionFailure("Attempting to encode a `Result.failure` should never be done.")
            throw EncodingError.encodedErrorResult(encodingError: error)
        }
    }
}