Merge pull request #11081 from itaiferber/4.0-codable_support_for_nsarchival

[4.0] NSKeyed{Una,A}rchiver should support Codable

Author: itaiferber

stdlib/public/SDK/Foundation/Codable.swift

@@ -51,8 +51,7 @@ internal extension DecodingError {
         } else if value is [String : Any] {
             return "a dictionary"
         } else {
-            // This should never happen -- we somehow have a non-JSON type here.
-            preconditionFailure("Invalid storage type \(type(of: value)).")
+            return "\(type(of: value))"
         }
     }
 }

stdlib/public/SDK/Foundation/NSCoder.swift

@@ -129,6 +129,20 @@ extension NSCoder {
   }
 }
 
+//===----------------------------------------------------------------------===//
+// NSKeyedArchiver
+//===----------------------------------------------------------------------===//
+
+extension NSKeyedArchiver {
+  @nonobjc
+  @available(OSX 10.11, iOS 9.0, *)
+  public func encodeEncodable<T : Encodable>(_ value: T, forKey key: String) throws {
+    let plistEncoder = PropertyListEncoder()
+    let plist = try plistEncoder.encodeToTopLevelContainer(value)
+    self.encode(plist, forKey: key)
+  }
+}
+
 //===----------------------------------------------------------------------===//
 // NSKeyedUnarchiver
 //===----------------------------------------------------------------------===//
@@ -153,6 +167,48 @@ extension NSKeyedUnarchiver {
     try resolveError(error)
     return result
   }
+  
+  @nonobjc
+  private static let __plistClasses: [AnyClass] = [
+    NSArray.self,
+    NSData.self,
+    NSDate.self,
+    NSDictionary.self,
+    NSNumber.self,
+    NSString.self
+  ]
+
+  @nonobjc
+  @available(OSX 10.11, iOS 9.0, *)
+  public func decodeDecodable<T : Decodable>(_ type: T.Type, forKey key: String) -> T? {
+      guard let value = self.decodeObject(of: NSKeyedUnarchiver.__plistClasses, forKey: key) else {
+          return nil
+      }
+
+      let plistDecoder = PropertyListDecoder()
+      do {
+          return try plistDecoder.decode(T.self, fromTopLevel: value)
+      } catch {
+          self.failWithError(error)
+          return nil
+      }
+  }
+
+  @nonobjc
+  @available(OSX 10.11, iOS 9.0, *)
+  public func decodeTopLevelDecodable<T : Decodable>(_ type: T.Type, forKey key: String) throws  -> T? {
+    guard let value = try self.decodeTopLevelObject(of: NSKeyedUnarchiver.__plistClasses, forKey: key) else {
+      return nil
+    }
+
+    let plistDecoder = PropertyListDecoder()
+    do {
+      return try plistDecoder.decode(T.self, fromTopLevel: value)
+    } catch {
+      self.failWithError(error)
+      throw error;
+    }
+  }
 }
 
 

stdlib/public/SDK/Foundation/PlistEncoder.swift

@@ -50,6 +50,35 @@ open class PropertyListEncoder {
     /// - throws: `EncodingError.invalidValue` if a non-comforming 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<Value : Encodable>(_ value: Value) throws -> Data {
+      let topLevel = try encodeToTopLevelContainer(value)
+      if topLevel is NSNumber {
+          throw EncodingError.invalidValue(value,
+                                           EncodingError.Context(codingPath: [],
+                                                                 debugDescription: "Top-level \(Value.self) encoded as number property list fragment."))
+      } else if topLevel is NSString {
+          throw EncodingError.invalidValue(value,
+                                           EncodingError.Context(codingPath: [],
+                                                                 debugDescription: "Top-level \(Value.self) encoded as string property list fragment."))
+      } else if topLevel is NSDate {
+          throw EncodingError.invalidValue(value,
+                                           EncodingError.Context(codingPath: [],
+                                                                 debugDescription: "Top-level \(Value.self) encoded as date property list fragment."))
+      }
+      
+      do {
+          return try PropertyListSerialization.data(fromPropertyList: topLevel, format: self.outputFormat, options: 0)
+      } catch {
+          throw EncodingError.invalidValue(value, EncodingError.Context(codingPath: [], debugDescription: "Unable to encode the given top-level value as a property list", underlyingError: error))
+      }
+    }
+
+    /// Encodes the given top-level value and returns its plist-type representation.
+    ///
+    /// - parameter value: The value to encode.
+    /// - returns: A new top-level array or dictionary representing the value.
+    /// - 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.
+    internal func encodeToTopLevelContainer<Value : Encodable>(_ value: Value) throws -> Any {
         let encoder = _PlistEncoder(options: self.options)
         try value.encode(to: encoder)
 
@@ -60,25 +89,7 @@ open class PropertyListEncoder {
         }
 
         let topLevel = encoder.storage.popContainer()
-        if topLevel is NSNumber {
-            throw EncodingError.invalidValue(value,
-                                             EncodingError.Context(codingPath: [],
-                                                                   debugDescription: "Top-level \(Value.self) encoded as number property list fragment."))
-        } else if topLevel is NSString {
-            throw EncodingError.invalidValue(value,
-                                             EncodingError.Context(codingPath: [],
-                                                                   debugDescription: "Top-level \(Value.self) encoded as string property list fragment."))
-        } else if topLevel is NSDate {
-            throw EncodingError.invalidValue(value,
-                                             EncodingError.Context(codingPath: [],
-                                                                   debugDescription: "Top-level \(Value.self) encoded as date property list fragment."))
-        }
-
-        do {
-            return try PropertyListSerialization.data(fromPropertyList: topLevel, format: self.outputFormat, options: 0)
-        } catch {
-            throw EncodingError.invalidValue(value, EncodingError.Context(codingPath: [], debugDescription: "Unable to encode the given top-level value as a property list", underlyingError: error))
-        }
+        return topLevel
     }
 }
 
@@ -620,7 +631,19 @@ open class PropertyListDecoder {
         } catch {
             throw DecodingError.dataCorrupted(DecodingError.Context(codingPath: [], debugDescription: "The given data was not a valid property list.", underlyingError: error))
         }
-        let decoder = _PlistDecoder(referencing: topLevel, options: self.options)
+
+        return try decode(T.self, fromTopLevel: topLevel)
+    }
+
+    /// Decodes a top-level value of the given type from the given property list container (top-level array or dictionary).
+    ///
+    /// - parameter type: The type of the value to decode.
+    /// - parameter container: The top-level plist container.
+    /// - 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 a valid property list.
+    /// - throws: An error if any value throws an error during decoding.
+    internal func decode<T : Decodable>(_ type: T.Type, fromTopLevel container: Any) throws -> T {
+        let decoder = _PlistDecoder(referencing: container, options: self.options)
         return try T(from: decoder)
     }
 }

test/stdlib/NSKeyedArchival.swift

@@ -0,0 +1,183 @@
+// Copyright (c) 2014 - 2017 Apple Inc. and the Swift project authors
+// Licensed under Apache License v2.0 with Runtime Library Exception
+//
+// See https://swift.org/LICENSE.txt for license information
+// See https://swift.org/CONTRIBUTORS.txt for the list of Swift project authors
+//
+//===----------------------------------------------------------------------===//
+//
+// RUN: %target-run-simple-swift
+// REQUIRES: executable_test
+// REQUIRES: objc_interop
+
+import Foundation
+import StdlibUnittest
+
+// Since we test various apis with and without errors define these conveniences
+func expectError(_ verb: () throws -> ()) {
+  do {
+    try verb()
+    expectUnreachable("Expected to throw error!")
+ } catch {
+   // expected
+  }
+}
+func expectNoError(_ verb: () throws -> ()) {
+  do {
+    try verb()
+  } catch let error {
+    expectUnreachable("Did not expect to throw error! \(error)")
+  }
+}
+
+// Utilities for minimizing boiler plate in the tests
+@available(OSX 10.11, iOS 9.0, *)
+func archive(_ archival: (_: NSKeyedArchiver) throws -> Void) rethrows ->  Data {
+    let data = NSMutableData()
+    let ka = NSKeyedArchiver(forWritingWith: data)
+    do {
+      defer { ka.finishEncoding() }
+      try archival(ka)
+    }
+    expectNotEqual(data.length, 0)
+    return data as Data
+}
+
+@available(OSX 10.11, iOS 9.0, *)
+func unarchive(_ data: Data, _ unarchival: (_: NSKeyedUnarchiver) throws -> Void) rethrows -> Void {
+  let ku = NSKeyedUnarchiver(forReadingWith: data as Data)
+  ku.requiresSecureCoding = true
+  ku.decodingFailurePolicy = .setErrorAndReturn
+  try unarchival(ku)
+  ku.finishDecoding()
+}
+
+
+// MARK: - Data
+// simple struct comprised of entirely plist types
+struct Simple : Codable, Equatable {
+    var number: Int = 5
+    var string: String = "hello"
+    var data: Data = Data(bytes: [0, 1, 2, 3])
+    var array: [String] = ["stay", "a while", "and listen"]
+    var dictionary: [String:String] = ["Deckard": "Cain"]
+    static func ==(lhs: Simple, rhs: Simple) -> Bool {
+        return lhs.number == rhs.number && lhs.string == rhs.string && lhs.data == rhs.data && lhs.array == rhs.array && lhs.dictionary == rhs.dictionary
+    }
+}
+
+// simple struct comprised of entirely plist types
+struct ThrowingCodable : Codable {
+  public func encode(to encoder: Encoder) throws {
+    throw NSError(domain: "sad", code: 3)
+  }
+}
+
+// MARK - Tests
+@available(OSX 10.11, iOS 9.0, *)
+func test_simpleCodableSupport() {
+  let s = Simple()
+  
+  var data: Data? = nil
+  expectNoError {
+    data = try archive { archiver in
+      try archiver.encodeEncodable(s, forKey: "valid")
+      try archiver.encodeEncodable(s, forKey: "wrong-type")
+    }
+  }
+  
+  unarchive(data!) { unarchiver in
+    // confirm we can roundtrip our data
+    let roundtrip = unarchiver.decodeDecodable(Simple.self, forKey: "valid")
+    expectNotNil(roundtrip)
+    if let rt = roundtrip {
+        expectEqual(rt, s)
+    } 
+  
+    // also ask for something that is not there
+    let notThere = unarchiver.decodeDecodable(Simple.self, forKey: "not-there")
+    expectNil(notThere)
+    expectNil(unarchiver.error)
+  
+    // String != Simple so this should fail at the type level
+    let wrongType = unarchiver.decodeDecodable(String.self, forKey: "wrong-type")
+    expectNil(wrongType)
+    expectNotNil(unarchiver.error)
+  }
+}
+
+@available(OSX 10.11, iOS 9.0, *)
+func test_encodableErrorHandling() {
+  expectError {
+    _ = try archive { archiver in
+      try archiver.encodeEncodable(ThrowingCodable(), forKey: "non-codable")
+    }
+  }
+}
+
+@available(OSX 10.11, iOS 9.0, *)
+func test_readingNonCodableFromDecodeDecodable() {
+  var data: Data? = nil
+  expectNoError {
+    data = archive { archiver in
+      archiver.encode(NSDate(), forKey: "non-codable")
+    }
+  }
+
+  unarchive(data!) { unarchiver in
+    let nonCodable = unarchiver.decodeDecodable(Simple.self, forKey: "non-codable")
+    expectNil(nonCodable)
+    expectNotNil(unarchiver.error)
+  }
+}
+
+@available(OSX 10.11, iOS 9.0, *)
+func test_toplevelAPIVariants() {
+  let s = Simple()
+  var data: Data? = nil
+  expectNoError {
+    data = try archive { archiver in
+      try archiver.encodeEncodable(s, forKey: "valid")
+      try archiver.encodeEncodable(Date(), forKey: "non-codable")
+    }
+  }
+
+  unarchive(data!) { unarchiver in
+    var caught = false
+    do {
+      _ = try unarchiver.decodeTopLevelDecodable(Simple.self, forKey: "non-codable")
+    } catch {
+      caught = true
+    }
+    expectTrue(caught)
+  }
+
+  expectNoError {
+    _ = try unarchive(data!) { unarchiver in
+      let roundtrip = try unarchiver.decodeTopLevelDecodable(Simple.self, forKey: "valid")
+      expectNotNil(roundtrip)
+      if let rt = roundtrip {
+        expectEqual(rt, s)
+      }
+    }    
+  }
+}
+
+// MARK: - Run Tests
+
+#if !FOUNDATION_XCTEST
+if #available(OSX 10.11, iOS 9.0, *) {
+  let NSKeyedArchiverTest = TestSuite("TestNSKeyedArchiver")
+  let tests = [
+    "NSKeyedArchival.simpleCodableSupportInNSKeyedArchival": test_simpleCodableSupport,
+    "NSKeyedArchival.encodableErrorHandling": test_encodableErrorHandling,
+    "NSKeyedArchival.readingNonCodableFromDecodeDecodable": test_readingNonCodableFromDecodeDecodable,
+    "NSKeyedArchival.toplevelAPIVariants": test_toplevelAPIVariants
+  ]
+  
+  for (name, test) in tests {
+    NSKeyedArchiverTest.test(name) { test() }
+  }
+  runAllTests()
+}
+#endif