From 9e7c781737a0c1de270c648c90642588b7c98681 Mon Sep 17 00:00:00 2001
From: Max Desiatov <max@desiatov.com>
Date: Mon, 2 May 2022 14:42:27 +0100
Subject: [PATCH 1/2] Add ArrayBuffer, JSTypedArray and Data conversion

---
 Sources/DOMKit/ECMAScript/ArrayBuffer.swift | 27 ++++++++++++++++++---
 Tests/DOMKitTests/DOMKitTests.swift         | 19 +++++++++++++--
 2 files changed, 41 insertions(+), 5 deletions(-)

diff --git a/Sources/DOMKit/ECMAScript/ArrayBuffer.swift b/Sources/DOMKit/ECMAScript/ArrayBuffer.swift
index 195bbd54..9ecb04b4 100644
--- a/Sources/DOMKit/ECMAScript/ArrayBuffer.swift
+++ b/Sources/DOMKit/ECMAScript/ArrayBuffer.swift
@@ -2,8 +2,8 @@
 //  Created by Manuel Burghard. Licensed unter MIT.
 //
 
-import JavaScriptKit
 import _CJavaScriptKit
+import JavaScriptKit
 
 public typealias Int8Array = JSTypedArray<Int8>
 public typealias Int16Array = JSTypedArray<Int16>
@@ -15,7 +15,6 @@ public typealias Float32Array = JSTypedArray<Float32>
 public typealias Float64Array = JSTypedArray<Float64>
 
 public class ArrayBuffer: JSBridgedClass {
-
     public class var constructor: JSFunction { JSObject.global.ArrayBuffer.function! }
 
     public let jsObject: JSObject
@@ -25,10 +24,32 @@ public class ArrayBuffer: JSBridgedClass {
     }
 
     public convenience init(length: Int) {
-        self.init(unsafelyWrapping: Self.constructor.new( length))
+        self.init(unsafelyWrapping: Self.constructor.new(length))
     }
 
     public static func isView(_ object: JSValueCompatible) -> Bool {
         JSObject.global.ArrayBuffer.object!.isView!(object).fromJSValue()!
     }
 }
+
+extension JSTypedArray {
+    convenience init(_ arrayBuffer: ArrayBuffer) {
+        self.init(unsafelyWrapping: Self.constructor.new(arrayBuffer))
+    }
+
+    var buffer: ArrayBuffer {
+        ArrayBuffer(unsafelyWrapping: jsObject.buffer.object!)
+    }
+}
+
+#if canImport(Foundation)
+import Foundation
+
+extension Data {
+    init(_ arrayBuffer: ArrayBuffer) {
+        self = JSTypedArray<UInt8>(arrayBuffer).withUnsafeBytes {
+            Data(buffer: $0)
+        }
+    }
+}
+#endif
diff --git a/Tests/DOMKitTests/DOMKitTests.swift b/Tests/DOMKitTests/DOMKitTests.swift
index 4015104f..10515a66 100644
--- a/Tests/DOMKitTests/DOMKitTests.swift
+++ b/Tests/DOMKitTests/DOMKitTests.swift
@@ -1,8 +1,10 @@
-import XCTest
 import DOMKit
+import Foundation
+import JavaScriptKit
+import XCTest
 
 final class DOMKitTests: XCTestCase {
-    func testExample() {
+    func testQuerySelector() {
         let document = globalThis.document
         let button = document.createElement(localName: "button")
         button.textContent = "Hello, world!"
@@ -11,4 +13,17 @@ final class DOMKitTests: XCTestCase {
         let queriedButton = document.querySelector(selectors: "body button")
         XCTAssertEqual(queriedButton?.textContent, "Hello, world!")
     }
+
+    func testDataBuffer() {
+        let array: [UInt8] = [1, 2, 3, 4, 5]
+        let data = Data(array)
+        let typedArray = JSTypedArray(data)
+
+        typedArray.withUnsafeBytes {
+            XCTAssertEqual($0.count, data.count)
+            for index in $0.indices {
+                XCTAssertEqual(array[index], $0[index])
+            }
+        }
+    }
 }

From fa18508d6335d0205b581b56c6ee680d6ac08f0a Mon Sep 17 00:00:00 2001
From: Max Desiatov <max@desiatov.com>
Date: Mon, 2 May 2022 14:45:56 +0100
Subject: [PATCH 2/2] Add `testTypedArrayToData` test

---
 Sources/DOMKit/ECMAScript/ArrayBuffer.swift |  4 ++--
 Tests/DOMKitTests/DOMKitTests.swift         | 16 +++++++++++++++-
 2 files changed, 17 insertions(+), 3 deletions(-)

diff --git a/Sources/DOMKit/ECMAScript/ArrayBuffer.swift b/Sources/DOMKit/ECMAScript/ArrayBuffer.swift
index 9ecb04b4..9b4e8a9d 100644
--- a/Sources/DOMKit/ECMAScript/ArrayBuffer.swift
+++ b/Sources/DOMKit/ECMAScript/ArrayBuffer.swift
@@ -32,7 +32,7 @@ public class ArrayBuffer: JSBridgedClass {
     }
 }
 
-extension JSTypedArray {
+public extension JSTypedArray {
     convenience init(_ arrayBuffer: ArrayBuffer) {
         self.init(unsafelyWrapping: Self.constructor.new(arrayBuffer))
     }
@@ -45,7 +45,7 @@ extension JSTypedArray {
 #if canImport(Foundation)
 import Foundation
 
-extension Data {
+public extension Data {
     init(_ arrayBuffer: ArrayBuffer) {
         self = JSTypedArray<UInt8>(arrayBuffer).withUnsafeBytes {
             Data(buffer: $0)
diff --git a/Tests/DOMKitTests/DOMKitTests.swift b/Tests/DOMKitTests/DOMKitTests.swift
index 10515a66..16cf7424 100644
--- a/Tests/DOMKitTests/DOMKitTests.swift
+++ b/Tests/DOMKitTests/DOMKitTests.swift
@@ -14,7 +14,7 @@ final class DOMKitTests: XCTestCase {
         XCTAssertEqual(queriedButton?.textContent, "Hello, world!")
     }
 
-    func testDataBuffer() {
+    func testDataToTypedArray() {
         let array: [UInt8] = [1, 2, 3, 4, 5]
         let data = Data(array)
         let typedArray = JSTypedArray(data)
@@ -26,4 +26,18 @@ final class DOMKitTests: XCTestCase {
             }
         }
     }
+
+    func testTypedArrayToData() {
+        let array: [UInt8] = [1, 2, 3, 4, 5]
+        let typedArray = JSTypedArray(array)
+
+        let data = Data(typedArray.buffer)
+
+        typedArray.withUnsafeBytes {
+            XCTAssertEqual($0.count, data.count)
+            for index in $0.indices {
+                XCTAssertEqual(array[index], $0[index])
+            }
+        }
+    }
 }