Define encode/decode in terms of NSDictionary.

Added more tests.

Sources/DictionaryCoding/DictionaryDecoder.swift

@@ -184,7 +184,7 @@ open class DictionaryDecoder {
     /// - returns: A value of the requested type.
     /// - throws: `DecodingError.dataCorrupted` if values requested from the payload are corrupted, or if the given data is not valid Dictionary.
     /// - throws: An error if any value throws an error during decoding.
-    open func decode<T : Decodable>(_ type: T.Type, from dictionary: [String:Any]) throws -> T {
+    open func decode<T : Decodable>(_ type: T.Type, from dictionary: NSDictionary) throws -> T {
         let decoder = _DictionaryDecoder(referencing: dictionary, options: self.options)
         guard let value = try decoder.unbox(dictionary, as: type) else {
             throw DecodingError.valueNotFound(type, DecodingError.Context(codingPath: [], debugDescription: "The given data did not contain a top-level value."))

Sources/DictionaryCoding/DictionaryEncoder.swift

@@ -196,7 +196,7 @@ open class DictionaryEncoder {
     /// - returns: A new `Data` value containing the encoded Dictionary data.
     /// - throws: `EncodingError.invalidValue` if a non-conforming floating-point value is encountered during encoding, and the encoding strategy is `.throw`.
     /// - throws: An error if any value throws an error during encoding.
-  open func encode<T : Encodable>(_ value: T) throws -> [String:Any] {
+  open func encode<T : Encodable>(_ value: T) throws -> NSDictionary {
         let encoder = _DictionaryEncoder(options: self.options)
 
         guard let topLevel = try encoder.box_(value) else {
@@ -211,7 +211,7 @@ open class DictionaryEncoder {
             throw EncodingError.invalidValue(value, EncodingError.Context(codingPath: [], debugDescription: "Top-level \(T.self) encoded as string Dictionary fragment."))
         }
 
-      return topLevel as! [String:Any]
+      return topLevel as! NSDictionary
     }
 }
 

Tests/DictionaryCodingTests/DictionaryCodingTests.swift

@@ -1,23 +1,71 @@
 import XCTest
 @testable import DictionaryCoding
 
-struct Test : Codable {
+struct Pet : Codable {
   let name : String
 }
 
+struct Person : Codable {
+  let name : String
+  let age : Int
+  let pets : [Pet]
+}
+
 class DictionaryCodingTests: XCTestCase {
-    func testExample() throws {
-      let test = Test(name: "Brad")
+
+    func testEncoding() throws {
+      let test = Person(name: "Sam", age: 48, pets:[Pet(name: "Morven"), Pet(name: "Rebus")])
       let encoder = DictionaryEncoder()
       let encoded = try encoder.encode(test)
-      print("\(encoded)")
-
-      let decoder = DictionaryDecoder()
-      let decoded = try decoder.decode(Test.self, from: encoded)
-      print("\(decoded)")
+      XCTAssertEqual(encoded["name"] as? String, "Sam")
+      XCTAssertEqual(encoded["age"] as? Int, 48)
     }
 
-    static var allTests = [
-        ("testExample", testExample),
+  func testDecodingNSDictionary() throws {
+    let pet1 : NSMutableDictionary = NSMutableDictionary()
+    pet1["name"] = "Morven"
+    let pet2 : NSMutableDictionary = NSMutableDictionary()
+    pet2["name"] = "Rebus"
+    let pets : NSMutableArray = NSMutableArray()
+    pets.add(pet1)
+    pets.add(pet2)
+    let dict : NSMutableDictionary = NSMutableDictionary()
+    dict["name"] = "Sam"
+    dict["age"] = 48
+    dict["pets"] = pets
+
+    let decoder = DictionaryDecoder()
+    let decoded = try decoder.decode(Person.self, from: dict)
+
+    XCTAssertEqual(decoded.name, "Sam")
+    XCTAssertEqual(decoded.age, 48)
+    XCTAssertEqual(decoded.pets.count, 2)
+    XCTAssertEqual(decoded.pets[0].name, "Morven")
+    XCTAssertEqual(decoded.pets[1].name, "Rebus")
+  }
+
+  func testDecodingCFDictionary() throws {
+    let dict = [ "name" : "Sam", "age" : 48, "pets" : [ ["name" : "Morven"], ["name" : "Rebus"]]] as CFDictionary
+
+    let decoder = DictionaryDecoder()
+    let decoded = try decoder.decode(Person.self, from: dict)
+
+    XCTAssertEqual(decoded.name, "Sam")
+    XCTAssertEqual(decoded.age, 48)
+    XCTAssertEqual(decoded.pets.count, 2)
+    XCTAssertEqual(decoded.pets[0].name, "Morven")
+    XCTAssertEqual(decoded.pets[1].name, "Rebus")
+  }
+
+  func testFailureWithMissingKeys() {
+    let dict = [ "name" : "Sam", "age" : 48 ] as NSDictionary
+    let decoder = DictionaryDecoder()
+    XCTAssertThrowsError(try decoder.decode(Person.self, from: dict))
+  }
+
+  static var allTests = [
+        ("testEncoding", testEncoding),
+        ("testDecodingNSDictionary", testDecodingNSDictionary),
+        ("testDecodingCFDictionary", testDecodingCFDictionary),
     ]
 }