SR-8649: Range types conform to Codable

stdlib/public/core/ClosedRange.swift

@@ -488,3 +488,26 @@ extension ClosedRange {
 // shorthand. TODO: Add documentation
 public typealias CountableClosedRange<Bound: Strideable> = ClosedRange<Bound>
   where Bound.Stride : SignedInteger
+
+extension ClosedRange: Decodable where Bound: Decodable {
+  public init(from decoder: Decoder) throws {
+    var container = try decoder.unkeyedContainer()
+    let lowerBound = try container.decode(Bound.self)
+    let upperBound = try container.decode(Bound.self)
+    guard lowerBound <= upperBound else {
+      throw DecodingError.dataCorrupted(
+        DecodingError.Context(
+          codingPath: decoder.codingPath,
+          debugDescription: "Cannot initialize \(ClosedRange.self) with a lowerBound (\(lowerBound)) greater than upperBound (\(upperBound))"))
+    }
+    self.init(uncheckedBounds: (lower: lowerBound, upper: upperBound))
+  }
+}
+
+extension ClosedRange: Encodable where Bound: Encodable {
+  public func encode(to encoder: Encoder) throws {
+    var container = encoder.unkeyedContainer()
+    try container.encode(self.lowerBound)
+    try container.encode(self.upperBound)
+  }
+}

stdlib/public/core/Range.swift

@@ -405,6 +405,29 @@ extension Range: Hashable where Bound: Hashable {
   }
 }
 
+extension Range: Decodable where Bound: Decodable {
+  public init(from decoder: Decoder) throws {
+    var container = try decoder.unkeyedContainer()
+    let lowerBound = try container.decode(Bound.self)
+    let upperBound = try container.decode(Bound.self)
+    guard lowerBound <= upperBound else {
+      throw DecodingError.dataCorrupted(
+        DecodingError.Context(
+          codingPath: decoder.codingPath,
+          debugDescription: "Cannot initialize \(Range.self) with a lowerBound (\(lowerBound)) greater than upperBound (\(upperBound))"))
+    }
+    self.init(uncheckedBounds: (lower: lowerBound, upper: upperBound))
+  }
+}
+
+extension Range: Encodable where Bound: Encodable {
+  public func encode(to encoder: Encoder) throws {
+    var container = encoder.unkeyedContainer()
+    try container.encode(self.lowerBound)
+    try container.encode(self.upperBound)
+  }
+}
+
 /// A partial half-open interval up to, but not including, an upper bound.
 ///
 /// You create `PartialRangeUpTo` instances by using the prefix half-open range
@@ -447,6 +470,20 @@ extension PartialRangeUpTo: RangeExpression {
   }
 }
 
+extension PartialRangeUpTo: Decodable where Bound: Decodable {
+  public init(from decoder: Decoder) throws {
+    var container = try decoder.unkeyedContainer()
+    try self.init(container.decode(Bound.self))
+  }
+}
+
+extension PartialRangeUpTo: Encodable where Bound: Encodable {
+  public func encode(to encoder: Encoder) throws {
+    var container = encoder.unkeyedContainer()
+    try container.encode(self.upperBound)
+  }
+}
+
 /// A partial interval up to, and including, an upper bound.
 ///
 /// You create `PartialRangeThrough` instances by using the prefix closed range
@@ -488,6 +525,20 @@ extension PartialRangeThrough: RangeExpression {
   }
 }
 
+extension PartialRangeThrough: Decodable where Bound: Decodable {
+  public init(from decoder: Decoder) throws {
+    var container = try decoder.unkeyedContainer()
+    try self.init(container.decode(Bound.self))
+  }
+}
+
+extension PartialRangeThrough: Encodable where Bound: Encodable {
+  public func encode(to encoder: Encoder) throws {
+    var container = encoder.unkeyedContainer()
+    try container.encode(self.upperBound)
+  }
+}
+
 /// A partial interval extending upward from a lower bound.
 ///
 /// You create `PartialRangeFrom` instances by using the postfix range operator
@@ -624,6 +675,20 @@ extension PartialRangeFrom: Sequence
   }
 }
 
+extension PartialRangeFrom: Decodable where Bound: Decodable {
+  public init(from decoder: Decoder) throws {
+    var container = try decoder.unkeyedContainer()
+    try self.init(container.decode(Bound.self))
+  }
+}
+
+extension PartialRangeFrom: Encodable where Bound: Encodable {
+  public func encode(to encoder: Encoder) throws {
+    var container = encoder.unkeyedContainer()
+    try container.encode(self.lowerBound)
+  }
+}
+
 extension Comparable {
   /// Returns a half-open range that contains its lower bound but not its upper
   /// bound.

test/stdlib/CodableTests.swift

@@ -49,20 +49,25 @@ func debugDescription<T>(_ value: T) -> String {
     }
 }
 
-func expectRoundTripEquality<T : Codable>(of value: T, encode: (T) throws -> Data, decode: (Data) throws -> T, lineNumber: Int) where T : Equatable {
+func performEncodeAndDecode<T : Codable>(of value: T, encode: (T) throws -> Data, decode: (T.Type, Data) throws -> T, lineNumber: Int) -> T {
+
     let data: Data
     do {
         data = try encode(value)
     } catch {
         fatalError("\(#file):\(lineNumber): Unable to encode \(T.self) <\(debugDescription(value))>: \(error)")
     }
 
-    let decoded: T
     do {
-        decoded = try decode(data)
+        return try decode(T.self, data)
     } catch {
         fatalError("\(#file):\(lineNumber): Unable to decode \(T.self) <\(debugDescription(value))>: \(error)")
     }
+}
+
+func expectRoundTripEquality<T : Codable>(of value: T, encode: (T) throws -> Data, decode: (T.Type, Data) throws -> T, lineNumber: Int) where T : Equatable {
+
+    let decoded = performEncodeAndDecode(of: value, encode: encode, decode: decode, lineNumber: lineNumber)
 
     expectEqual(value, decoded, "\(#file):\(lineNumber): Decoded \(T.self) <\(debugDescription(decoded))> not equal to original <\(debugDescription(value))>")
 }
@@ -77,12 +82,12 @@ func expectRoundTripEqualityThroughJSON<T : Codable>(for value: T, lineNumber: I
         return try encoder.encode(value)
     }
 
-    let decode = { (_ data: Data) throws -> T in
+    let decode = { (_ type: T.Type, _ data: Data) throws -> T in
         let decoder = JSONDecoder()
         decoder.nonConformingFloatDecodingStrategy = .convertFromString(positiveInfinity: inf,
                                                                         negativeInfinity: negInf,
                                                                         nan: nan)
-        return try decoder.decode(T.self, from: data)
+        return try decoder.decode(type, from: data)
     }
 
     expectRoundTripEquality(of: value, encode: encode, decode: decode, lineNumber: lineNumber)
@@ -93,8 +98,8 @@ func expectRoundTripEqualityThroughPlist<T : Codable>(for value: T, lineNumber:
         return try PropertyListEncoder().encode(value)
     }
 
-    let decode = { (_ data: Data) throws -> T in
-        return try PropertyListDecoder().decode(T.self, from: data)
+    let decode = { (_ type: T.Type,_ data: Data) throws -> T in
+        return try PropertyListDecoder().decode(type, from: data)
     }
 
     expectRoundTripEquality(of: value, encode: encode, decode: decode, lineNumber: lineNumber)
@@ -351,6 +356,21 @@ class TestCodable : TestCodableSuper {
         }
     }
 
+    // MARK: - ClosedRange
+    func test_ClosedRange_JSON() {
+        let value = 0...Int.max
+        let decoded = performEncodeAndDecode(of: value, encode: { try JSONEncoder().encode($0) }, decode: { try JSONDecoder().decode($0, from: $1)  }, lineNumber: #line)
+        expectEqual(value.upperBound, decoded.upperBound, "\(#file):\(#line): Decoded ClosedRange upperBound <\(debugDescription(decoded))> not equal to original <\(debugDescription(value))>")
+        expectEqual(value.lowerBound, decoded.lowerBound, "\(#file):\(#line): Decoded ClosedRange lowerBound <\(debugDescription(decoded))> not equal to original <\(debugDescription(value))>")
+    }
+
+    func test_ClosedRange_Plist() {
+        let value = 0...Int.max
+        let decoded = performEncodeAndDecode(of: value, encode: { try PropertyListEncoder().encode($0) }, decode: { try PropertyListDecoder().decode($0, from: $1)  }, lineNumber: #line)
+        expectEqual(value.upperBound, decoded.upperBound, "\(#file):\(#line): Decoded ClosedRange upperBound <\(debugDescription(decoded))> not equal to original <\(debugDescription(value))>")
+        expectEqual(value.lowerBound, decoded.lowerBound, "\(#file):\(#line): Decoded ClosedRange lowerBound <\(debugDescription(decoded))> not equal to original <\(debugDescription(value))>")
+    }
+
     // MARK: - DateComponents
     lazy var dateComponents: Set<Calendar.Component> = [
         .era, .year, .month, .day, .hour, .minute, .second, .nanosecond,
@@ -522,6 +542,45 @@ class TestCodable : TestCodableSuper {
         }
     }
 
+    // MARK: - PartialRangeFrom
+    func test_PartialRangeFrom_JSON() {
+        let value = 0...
+        let decoded = performEncodeAndDecode(of: value, encode: { try JSONEncoder().encode($0) }, decode: { try JSONDecoder().decode($0, from: $1)  }, lineNumber: #line)
+        expectEqual(value.lowerBound, decoded.lowerBound, "\(#file):\(#line): Decoded PartialRangeFrom <\(debugDescription(decoded))> not equal to original <\(debugDescription(value))>")
+    }
+
+    func test_PartialRangeFrom_Plist() {
+        let value = 0...
+        let decoded = performEncodeAndDecode(of: value, encode: { try PropertyListEncoder().encode($0) }, decode: { try PropertyListDecoder().decode($0, from: $1)  }, lineNumber: #line)
+        expectEqual(value.lowerBound, decoded.lowerBound, "\(#file):\(#line): Decoded PartialRangeFrom <\(debugDescription(decoded))> not equal to original <\(debugDescription(value))>")
+    }
+
+    // MARK: - PartialRangeThrough
+    func test_PartialRangeThrough_JSON() {
+        let value = ...Int.max
+        let decoded = performEncodeAndDecode(of: value, encode: { try JSONEncoder().encode($0) }, decode: { try JSONDecoder().decode($0, from: $1)  }, lineNumber: #line)
+        expectEqual(value.upperBound, decoded.upperBound, "\(#file):\(#line): Decoded PartialRangeThrough <\(debugDescription(decoded))> not equal to original <\(debugDescription(value))>")
+    }
+
+    func test_PartialRangeThrough_Plist() {
+        let value = ...Int.max
+        let decoded = performEncodeAndDecode(of: value, encode: { try PropertyListEncoder().encode($0) }, decode: { try PropertyListDecoder().decode($0, from: $1)  }, lineNumber: #line)
+        expectEqual(value.upperBound, decoded.upperBound, "\(#file):\(#line): Decoded PartialRangeThrough <\(debugDescription(decoded))> not equal to original <\(debugDescription(value))>")
+    }
+
+    // MARK: - PartialRangeUpTo
+    func test_PartialRangeUpTo_JSON() {
+        let value = ..<Int.max
+        let decoded = performEncodeAndDecode(of: value, encode: { try JSONEncoder().encode($0) }, decode: { try JSONDecoder().decode($0, from: $1)  }, lineNumber: #line)
+        expectEqual(value.upperBound, decoded.upperBound, "\(#file):\(#line): Decoded PartialRangeUpTo <\(debugDescription(decoded))> not equal to original <\(debugDescription(value))>")
+    }
+
+    func test_PartialRangeUpTo_Plist() {
+        let value = ..<Int.max
+        let decoded = performEncodeAndDecode(of: value, encode: { try PropertyListEncoder().encode($0) }, decode: { try PropertyListDecoder().decode($0, from: $1)  }, lineNumber: #line)
+        expectEqual(value.upperBound, decoded.upperBound, "\(#file):\(#line): Decoded PartialRangeUpTo <\(debugDescription(decoded))> not equal to original <\(debugDescription(value))>")
+    }
+
     // MARK: - PersonNameComponents
     @available(macOS 10.11, iOS 9.0, watchOS 2.0, tvOS 9.0, *)
     lazy var personNameComponentsValues: [Int : PersonNameComponents] = [
@@ -544,6 +603,21 @@ class TestCodable : TestCodableSuper {
         }
     }
 
+    // MARK: - Range
+    func test_Range_JSON() {
+        let value = 0..<Int.max
+        let decoded = performEncodeAndDecode(of: value, encode: { try JSONEncoder().encode($0) }, decode: { try JSONDecoder().decode($0, from: $1)  }, lineNumber: #line)
+        expectEqual(value.upperBound, decoded.upperBound, "\(#file):\(#line): Decoded Range upperBound <\(debugDescription(decoded))> not equal to original <\(debugDescription(value))>")
+        expectEqual(value.lowerBound, decoded.lowerBound, "\(#file):\(#line): Decoded Range lowerBound<\(debugDescription(decoded))> not equal to original <\(debugDescription(value))>")
+    }
+
+    func test_Range_Plist() {
+        let value = 0..<Int.max
+        let decoded = performEncodeAndDecode(of: value, encode: { try PropertyListEncoder().encode($0) }, decode: { try PropertyListDecoder().decode($0, from: $1)  }, lineNumber: #line)
+        expectEqual(value.upperBound, decoded.upperBound, "\(#file):\(#line): Decoded Range upperBound<\(debugDescription(decoded))> not equal to original <\(debugDescription(value))>")
+        expectEqual(value.lowerBound, decoded.lowerBound, "\(#file):\(#line): Decoded Range lowerBound<\(debugDescription(decoded))> not equal to original <\(debugDescription(value))>")
+    }
+
     // MARK: - TimeZone
     lazy var timeZoneValues: [Int : TimeZone] = [
         #line : TimeZone(identifier: "America/Los_Angeles")!,
@@ -754,6 +828,8 @@ var tests = [
     "test_CGRect_Plist" : TestCodable.test_CGRect_Plist,
     "test_CGVector_JSON" : TestCodable.test_CGVector_JSON,
     "test_CGVector_Plist" : TestCodable.test_CGVector_Plist,
+    "test_ClosedRange_JSON" : TestCodable.test_ClosedRange_JSON,
+    "test_ClosedRange_Plist" : TestCodable.test_ClosedRange_Plist,
     "test_DateComponents_JSON" : TestCodable.test_DateComponents_JSON,
     "test_DateComponents_Plist" : TestCodable.test_DateComponents_Plist,
     "test_Decimal_JSON" : TestCodable.test_Decimal_JSON,
@@ -766,6 +842,14 @@ var tests = [
     "test_Locale_Plist" : TestCodable.test_Locale_Plist,
     "test_NSRange_JSON" : TestCodable.test_NSRange_JSON,
     "test_NSRange_Plist" : TestCodable.test_NSRange_Plist,
+    "test_PartialRangeFrom_JSON" : TestCodable.test_PartialRangeFrom_JSON,
+    "test_PartialRangeFrom_Plist" : TestCodable.test_PartialRangeFrom_Plist,
+    "test_PartialRangeThrough_JSON" : TestCodable.test_PartialRangeThrough_JSON,
+    "test_PartialRangeThrough_Plist" : TestCodable.test_PartialRangeThrough_Plist,
+    "test_PartialRangeUpTo_JSON" : TestCodable.test_PartialRangeUpTo_JSON,
+    "test_PartialRangeUpTo_Plist" : TestCodable.test_PartialRangeUpTo_Plist,
+    "test_Range_JSON" : TestCodable.test_Range_JSON,
+    "test_Range_Plist" : TestCodable.test_Range_Plist,
     "test_TimeZone_JSON" : TestCodable.test_TimeZone_JSON,
     "test_TimeZone_Plist" : TestCodable.test_TimeZone_Plist,
     "test_URL_JSON" : TestCodable.test_URL_JSON,