issue-1891: API Addition for JSONSerialization in NIOFoundationCompat (#1906)

Motivation:

Issue for #1891 to add JSONSerialization in NIOFoundationCompat.

Modifications:

Adds:
JSONSerialization+ByteBuffer.swift
JSONSerialization+ByteBufferTest.swift
JSONSerialization+ByteBufferTest+XCTest.swift

Result:

Support for transforming byteBuffer data to a Foundation object.

Co-authored-by: Cory Benfield <[email protected]>

Author: agnosticdev

Sources/NIOFoundationCompat/JSONSerialization+ByteBuffer.swift

@@ -0,0 +1,31 @@
+//===----------------------------------------------------------------------===//
+//
+// This source file is part of the SwiftNIO open source project
+//
+// Copyright (c) 2021 Apple Inc. and the SwiftNIO project authors
+// Licensed under Apache License v2.0
+//
+// See LICENSE.txt for license information
+// See CONTRIBUTORS.txt for the list of SwiftNIO project authors
+//
+// SPDX-License-Identifier: Apache-2.0
+//
+//===----------------------------------------------------------------------===//
+
+import NIO
+import Foundation
+
+extension JSONSerialization {
+    
+    /// Attempts to derive a Foundation object from a ByteBuffer and return it as `T`.
+    ///
+    /// - parameters:
+    ///    - buffer: The ByteBuffer being used to derive the Foundation type.
+    ///    - options: The reading option used when the parser derives the Foundation type from the ByteBuffer.
+    /// - returns: The Foundation value if successful or `nil` if there was an issue creating the Foundation type.
+    @inlinable
+    public static func jsonObject(with buffer: ByteBuffer,
+                                  options opt: JSONSerialization.ReadingOptions = []) throws -> Any {
+        return try JSONSerialization.jsonObject(with: Data(buffer: buffer), options: opt)
+    }
+}

Tests/LinuxMain.swift

@@ -91,6 +91,7 @@ class LinuxMainRunnerImpl: LinuxMainRunner {
              testCase(IdleStateHandlerTest.allTests),
              testCase(IntegerBitPackingTests.allTests),
              testCase(IntegerTypesTest.allTests),
+             testCase(JSONSerializationByteBufferTest.allTests),
              testCase(LinuxTest.allTests),
              testCase(MarkedCircularBufferTests.allTests),
              testCase(MessageToByteEncoderTest.allTests),

Tests/NIOFoundationCompatTests/JSONSerialization+ByteBufferTest+XCTest.swift

@@ -0,0 +1,34 @@
+//===----------------------------------------------------------------------===//
+//
+// This source file is part of the SwiftNIO open source project
+//
+// Copyright (c) 2017-2021 Apple Inc. and the SwiftNIO project authors
+// Licensed under Apache License v2.0
+//
+// See LICENSE.txt for license information
+// See CONTRIBUTORS.txt for the list of SwiftNIO project authors
+//
+// SPDX-License-Identifier: Apache-2.0
+//
+//===----------------------------------------------------------------------===//
+//
+// JSONSerialization+ByteBufferTest+XCTest.swift
+//
+import XCTest
+
+///
+/// NOTE: This file was generated by generate_linux_tests.rb
+///
+/// Do NOT edit this file directly as it will be regenerated automatically when needed.
+///
+
+extension JSONSerializationByteBufferTest {
+
+   @available(*, deprecated, message: "not actually deprecated. Just deprecated to allow deprecated tests (which test deprecated functionality) without warnings")
+   static var allTests : [(String, (JSONSerializationByteBufferTest) -> () throws -> Void)] {
+      return [
+                ("testSerializationRoundTrip", testSerializationRoundTrip),
+           ]
+   }
+}
+

Tests/NIOFoundationCompatTests/JSONSerialization+ByteBufferTest.swift

@@ -0,0 +1,56 @@
+//===----------------------------------------------------------------------===//
+//
+// This source file is part of the SwiftNIO open source project
+//
+// Copyright (c) 2021 Apple Inc. and the SwiftNIO project authors
+// Licensed under Apache License v2.0
+//
+// See LICENSE.txt for license information
+// See CONTRIBUTORS.txt for the list of SwiftNIO project authors
+//
+// SPDX-License-Identifier: Apache-2.0
+//
+//===----------------------------------------------------------------------===//
+
+import Foundation
+import XCTest
+import NIO
+import NIOFoundationCompat
+
+class JSONSerializationByteBufferTest: XCTestCase {
+    
+    func testSerializationRoundTrip() {
+        
+        let array = ["String1", "String2", "String3"]
+        let dictionary = ["key1": "val1", "key2": "val2", "key3": "val3"]
+        
+        var dataArray = Data()
+        var dataDictionary = Data()
+        
+        XCTAssertTrue(JSONSerialization.isValidJSONObject(array), "Array object cannot be converted to JSON")
+        XCTAssertTrue(JSONSerialization.isValidJSONObject(dictionary), "Dictionary object cannot be converted to JSON")
+        
+        XCTAssertNoThrow(dataArray = try JSONSerialization.data(withJSONObject: array, options: .prettyPrinted))
+        XCTAssertNoThrow(dataDictionary = try JSONSerialization.data(withJSONObject: dictionary, options: .prettyPrinted))
+        
+        let arrayByteBuffer = ByteBuffer(data: dataArray)
+        let dictByteBuffer = ByteBuffer(data: dataDictionary)
+        
+        var foundationArray: [String] = []
+        var foundationDict: [String: String] = [:]
+        
+        // Mutable containers comparison.
+        XCTAssertNoThrow(foundationArray = try JSONSerialization.jsonObject(with: arrayByteBuffer, options: .mutableContainers) as! [String])
+        XCTAssertEqual(foundationArray, array)
+        
+        XCTAssertNoThrow(foundationDict = try JSONSerialization.jsonObject(with: dictByteBuffer, options: .mutableContainers) as! [String : String])
+        XCTAssertEqual(foundationDict, dictionary)
+        
+        // Mutable leaves comparison.
+        XCTAssertNoThrow(foundationArray = try JSONSerialization.jsonObject(with: arrayByteBuffer, options: .mutableLeaves) as! [String])
+        XCTAssertEqual(foundationArray, array)
+        
+        XCTAssertNoThrow(foundationDict = try JSONSerialization.jsonObject(with: dictByteBuffer, options: .mutableLeaves) as! [String : String])
+        XCTAssertEqual(foundationDict, dictionary)
+    }
+}