JSONValue.swift

public enum JSONValue {
    case string(String)
    case int(Int)
    case double(Double)
    case bool(Bool)
    case object([String: JSONValue])
    case array([JSONValue])
}

extension JSONValue: Encodable {
    public func encode(to encoder: Encoder) throws {
        var container = encoder.singleValueContainer()
        switch self {
        case .string(let string): try container.encode(string)
        case .int(let int): try container.encode(int)
        case .double(let double): try container.encode(double)
        case .bool(let bool): try container.encode(bool)
        case .object(let object): try container.encode(object)
        case .array(let array): try container.encode(array)
        }
    }
}

extension JSONValue {
    func jsonString(file: StaticString =  #file, line: UInt = #line) -> String {
        do {
            guard let value = try String(data: JSONEncoder().encode(self), encoding: .utf8) else {
                fatalError("Error in test data! String could not be parsed from data", file: file, line: line)
            }
            return value
        } catch {
            fatalError("Error in test data! \(error.localizedDescription)", file: file, line: line)
        }
    }
}

extension JSONValue: ExpressibleByStringLiteral {
    public init(stringLiteral value: String) {
        self = .string(value)
    }
}

extension JSONValue: ExpressibleByIntegerLiteral {
    public init(integerLiteral value: Int) {
        self = .int(value)
    }
}

extension JSONValue: ExpressibleByFloatLiteral {
    public init(floatLiteral value: Double) {
        self = .double(value)
    }
}

extension JSONValue: ExpressibleByBooleanLiteral {
    public init(booleanLiteral value: Bool) {
        self = .bool(value)
    }
}

extension JSONValue: ExpressibleByArrayLiteral {
    public init(arrayLiteral elements: JSONValue...) {
        self = .array(elements)
    }
}

extension JSONValue: ExpressibleByDictionaryLiteral {
    public init(dictionaryLiteral elements: (String, JSONValue)...) {
        self = .object([String: JSONValue](uniqueKeysWithValues: elements))
    }
}