JSONSerialization PR review fixes

Author: spevans

Foundation/JSONSerialization.swift

@@ -105,7 +105,9 @@ open class JSONSerialization : NSObject {
             // For better performance, this (most expensive) test should be last.
             if let number = _SwiftValue.store(obj) as? NSNumber {
                 if CFNumberIsFloatType(number._cfObject) {
-                    return number.doubleValue.isFinite
+                    let dv = number.doubleValue
+                    let invalid = dv.isInfinite || dv.isNaN
+                    return !invalid
                 } else {
                     return true
                 }
@@ -368,22 +370,22 @@ private struct JSONWriter {
 
     private func serializeInteger<T: UnsignedInteger>(value: T, isNegative: Bool = false) {
         let maxIntLength = 22   // 20 digits in UInt64 + optional sign + trailing '\0'
-        let ZERO: CChar = 0x30  // ASCII '0' == 0x30
-        let MINUS: CChar = 0x2d // ASCII '-' == 0x2d
+        let asciiZero: CChar = 0x30  // ASCII '0' == 0x30
+        let asciiMinus: CChar = 0x2d // ASCII '-' == 0x2d
 
         var number = UInt64(value)
         var buffer = Array<CChar>(repeating: 0, count: maxIntLength)
         var pos = maxIntLength - 1
 
         repeat {
             pos -= 1
-            buffer[pos] = ZERO + CChar(number % 10)
+            buffer[pos] = asciiZero + CChar(number % 10)
             number /= 10
         } while number != 0
 
         if isNegative {
             pos -= 1
-            buffer[pos] = MINUS
+            buffer[pos] = asciiMinus
         }
         let output = String(cString: Array(buffer.suffix(from: pos)))
         writer(output)

TestFoundation/TestJSONEncoder.swift

@@ -406,10 +406,10 @@ class TestJSONEncoder : XCTestCase {
     func test_codingOfUIntMinMax() {
 
         struct MyValue: Codable {
-            let intMin = Int64.min
-            let intMax = Int64.max
-            let uintMin = UInt64.min
-            let uintMax = UInt64.max
+            let int64Min = Int64.min
+            let int64Max = Int64.max
+            let uint64Min = UInt64.min
+            let uint64Max = UInt64.max
         }
 
         func compareJSON(_ s1: String, _ s2: String) {
@@ -423,7 +423,7 @@ class TestJSONEncoder : XCTestCase {
             let myValue = MyValue()
             let result = try encoder.encode(myValue)
             let r = String(data: result, encoding: .utf8) ?? "nil"
-            compareJSON(r, "{\"uintMin\":0,\"uintMax\":18446744073709551615,\"intMin\":-9223372036854775808,\"intMax\":9223372036854775807}")
+            compareJSON(r, "{\"uint64Min\":0,\"uint64Max\":18446744073709551615,\"int64Min\":-9223372036854775808,\"int64Max\":9223372036854775807}")
         } catch {
             XCTFail(String(describing: error))
         }

TestFoundation/TestJSONSerialization.swift

@@ -941,13 +941,17 @@ extension TestJSONSerialization {
 
         XCTAssertFalse(JSONSerialization.isValidJSONObject(Float.nan))
         XCTAssertFalse(JSONSerialization.isValidJSONObject(Float.infinity))
+        XCTAssertFalse(JSONSerialization.isValidJSONObject(-Float.infinity))
         XCTAssertFalse(JSONSerialization.isValidJSONObject(NSNumber(value: Float.nan)))
         XCTAssertFalse(JSONSerialization.isValidJSONObject(NSNumber(value: Float.infinity)))
+        XCTAssertFalse(JSONSerialization.isValidJSONObject(NSNumber(value: -Float.infinity)))
 
         XCTAssertFalse(JSONSerialization.isValidJSONObject(Double.nan))
         XCTAssertFalse(JSONSerialization.isValidJSONObject(Double.infinity))
+        XCTAssertFalse(JSONSerialization.isValidJSONObject(-Double.infinity))
         XCTAssertFalse(JSONSerialization.isValidJSONObject(NSNumber(value: Double.nan)))
         XCTAssertFalse(JSONSerialization.isValidJSONObject(NSNumber(value: Double.infinity)))
+        XCTAssertFalse(JSONSerialization.isValidJSONObject(NSNumber(value: -Double.infinity)))
 
         XCTAssertFalse(JSONSerialization.isValidJSONObject(NSDecimalNumber(decimal: Decimal(floatLiteral: Double.nan))))
     }