Gracefully handle unavailable JSBridgedClass

Author: MaxDesiatov

Sources/JavaScriptKit/BasicObjects/JSArray.swift

@@ -1,10 +1,10 @@
 /// A wrapper around [the JavaScript Array class](https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/Array)
 /// that exposes its properties in a type-safe and Swifty way.
 public class JSArray: JSBridgedClass {
-    public static let constructor = JSObject.global.Array.function!
+    public static let constructor = JSObject.global.Array.function
 
     static func isArray(_ object: JSObject) -> Bool {
-        constructor.isArray!(object).boolean!
+        constructor!.isArray!(object).boolean!
     }
 
     public let jsObject: JSObject
@@ -94,8 +94,8 @@ private func getObjectValuesLength(_ object: JSObject) -> Int {
     return Int(values.length.number!)
 }
 
-extension JSValue {
-    public var array: JSArray? {
+public extension JSValue {
+    var array: JSArray? {
         object.flatMap(JSArray.init)
     }
 }

Sources/JavaScriptKit/BasicObjects/JSDate.swift

@@ -1,32 +1,32 @@
-/** A wrapper around the [JavaScript Date 
-class](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Date) that
-exposes its properties in a type-safe way. This doesn't 100% match the JS API, for example 
-`getMonth`/`setMonth` etc accessor methods are converted to properties, but the rest of it matches
-in the naming. Parts of the JavaScript `Date` API that are not consistent across browsers and JS 
-implementations are not exposed in a type-safe manner, you should access the underlying `jsObject`
-property if you need those.
-*/
+/** A wrapper around the [JavaScript Date
+ class](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Date) that
+ exposes its properties in a type-safe way. This doesn't 100% match the JS API, for example
+ `getMonth`/`setMonth` etc accessor methods are converted to properties, but the rest of it matches
+ in the naming. Parts of the JavaScript `Date` API that are not consistent across browsers and JS
+ implementations are not exposed in a type-safe manner, you should access the underlying `jsObject`
+ property if you need those.
+ */
 public final class JSDate: JSBridgedClass {
     /// The constructor function used to create new `Date` objects.
-    public static let constructor = JSObject.global.Date.function!
+    public static let constructor = JSObject.global.Date.function
 
     /// The underlying JavaScript `Date` object.
     public let jsObject: JSObject
 
     /** Creates a new instance of the JavaScript `Date` class with a given amount of milliseconds
-    that passed since midnight 01 January 1970 UTC.
-    */
+     that passed since midnight 01 January 1970 UTC.
+     */
     public init(millisecondsSinceEpoch: Double? = nil) {
         if let milliseconds = millisecondsSinceEpoch {
-            jsObject = Self.constructor.new(milliseconds)
+            jsObject = Self.constructor!.new(milliseconds)
         } else {
-            jsObject = Self.constructor.new()
+            jsObject = Self.constructor!.new()
         }
     }
 
-    /** According to the standard, `monthIndex` is zero-indexed, where `11` is December. `day` 
-    represents a day of the month starting at `1`.
-    */
+    /** According to the standard, `monthIndex` is zero-indexed, where `11` is December. `day`
+     represents a day of the month starting at `1`.
+     */
     public init(
         year: Int,
         monthIndex: Int,
@@ -36,7 +36,7 @@ public final class JSDate: JSBridgedClass {
         seconds: Int = 0,
         milliseconds: Int = 0
     ) {
-        jsObject = Self.constructor.new(year, monthIndex, day, hours, minutes, seconds, milliseconds)
+        jsObject = Self.constructor!.new(year, monthIndex, day, hours, minutes, seconds, milliseconds)
     }
 
     public init(unsafelyWrapping jsObject: JSObject) {
@@ -198,7 +198,7 @@ public final class JSDate: JSBridgedClass {
         Int(jsObject.getTimezoneOffset!().number!)
     }
 
-    /// Returns a string conforming to ISO 8601 that contains date and time, e.g. 
+    /// Returns a string conforming to ISO 8601 that contains date and time, e.g.
     /// `"2020-09-15T08:56:54.811Z"`.
     public func toISOString() -> String {
         jsObject.toISOString!().string!
@@ -214,25 +214,25 @@ public final class JSDate: JSBridgedClass {
         jsObject.toLocaleTimeString!().string!
     }
 
-    /** Returns a string formatted according to 
-    [rfc7231](https://tools.ietf.org/html/rfc7231#section-7.1.1.1) and modified according to 
-    [ecma-262](https://www.ecma-international.org/ecma-262/10.0/index.html#sec-date.prototype.toutcstring),
-    e.g. `Tue, 15 Sep 2020 09:04:40 GMT`.
-    */
+    /** Returns a string formatted according to
+     [rfc7231](https://tools.ietf.org/html/rfc7231#section-7.1.1.1) and modified according to
+     [ecma-262](https://www.ecma-international.org/ecma-262/10.0/index.html#sec-date.prototype.toutcstring),
+     e.g. `Tue, 15 Sep 2020 09:04:40 GMT`.
+     */
     public func toUTCString() -> String {
         jsObject.toUTCString!().string!
     }
 
-    /** Number of milliseconds since midnight 01 January 1970 UTC to the present moment ignoring 
-    leap seconds.
-    */
+    /** Number of milliseconds since midnight 01 January 1970 UTC to the present moment ignoring
+     leap seconds.
+     */
     public static func now() -> Double {
-        constructor.now!().number!
+        constructor!.now!().number!
     }
 
-    /** Number of milliseconds since midnight 01 January 1970 UTC to the given date ignoring leap 
-    seconds.
-    */
+    /** Number of milliseconds since midnight 01 January 1970 UTC to the given date ignoring leap
+     seconds.
+     */
     public func valueOf() -> Double {
         jsObject.valueOf!().number!
     }

Sources/JavaScriptKit/BasicObjects/JSError.swift

@@ -1,17 +1,17 @@
-/** A wrapper around [the JavaScript Error 
-class](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Error) that
-exposes its properties in a type-safe way.
-*/
+/** A wrapper around [the JavaScript Error
+ class](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Error) that
+ exposes its properties in a type-safe way.
+ */
 public final class JSError: Error, JSBridgedClass {
     /// The constructor function used to create new JavaScript `Error` objects.
-    public static let constructor = JSObject.global.Error.function!
+    public static let constructor = JSObject.global.Error.function
 
     /// The underlying JavaScript `Error` object.
     public let jsObject: JSObject
 
     /// Creates a new instance of the JavaScript `Error` class with a given message.
     public init(message: String) {
-        jsObject = Self.constructor.new([message])
+        jsObject = Self.constructor!.new([message])
     }
 
     public init(unsafelyWrapping jsObject: JSObject) {

Sources/JavaScriptKit/BasicObjects/JSPromise.swift

@@ -1,14 +1,14 @@
 /** A wrapper around [the JavaScript `Promise` class](https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/Promise)
-that exposes its functions in a type-safe and Swifty way. The `JSPromise` API is generic over both
-`Success` and `Failure` types, which improves compatibility with other statically-typed APIs such
-as Combine. If you don't know the exact type of your `Success` value, you should use `JSValue`, e.g.
-`JSPromise<JSValue, JSError>`. In the rare case, where you can't guarantee that the error thrown
-is of actual JavaScript `Error` type, you should use `JSPromise<JSValue, JSValue>`.
+ that exposes its functions in a type-safe and Swifty way. The `JSPromise` API is generic over both
+ `Success` and `Failure` types, which improves compatibility with other statically-typed APIs such
+ as Combine. If you don't know the exact type of your `Success` value, you should use `JSValue`, e.g.
+ `JSPromise<JSValue, JSError>`. In the rare case, where you can't guarantee that the error thrown
+ is of actual JavaScript `Error` type, you should use `JSPromise<JSValue, JSValue>`.
 
-This doesn't 100% match the JavaScript API, as `then` overload with two callbacks is not available.
-It's impossible to unify success and failure types from both callbacks in a single returned promise
-without type erasure. You should chain `then` and `catch` in those cases to avoid type erasure.
-*/
+ This doesn't 100% match the JavaScript API, as `then` overload with two callbacks is not available.
+ It's impossible to unify success and failure types from both callbacks in a single returned promise
+ without type erasure. You should chain `then` and `catch` in those cases to avoid type erasure.
+ */
 public final class JSPromise: JSBridgedClass {
     /// The underlying JavaScript `Promise` object.
     public let jsObject: JSObject
@@ -18,35 +18,35 @@ public final class JSPromise: JSBridgedClass {
         .object(jsObject)
     }
 
-    public static var constructor: JSFunction {
+    public static var constructor: JSFunction? {
         JSObject.global.Promise.function!
     }
 
     /// This private initializer assumes that the passed object is a JavaScript `Promise`
     public init(unsafelyWrapping object: JSObject) {
-        self.jsObject = object
+        jsObject = object
     }
 
     /** Creates a new `JSPromise` instance from a given JavaScript `Promise` object. If `jsObject`
-    is not an instance of JavaScript `Promise`, this initializer will return `nil`.
-    */
+     is not an instance of JavaScript `Promise`, this initializer will return `nil`.
+     */
     public convenience init?(_ jsObject: JSObject) {
         self.init(from: jsObject)
     }
 
     /** Creates a new `JSPromise` instance from a given JavaScript `Promise` object. If `value`
-    is not an object and is not an instance of JavaScript `Promise`, this function will 
-    return `nil`.
-    */
+     is not an object and is not an instance of JavaScript `Promise`, this function will
+     return `nil`.
+     */
     public static func construct(from value: JSValue) -> Self? {
         guard case let .object(jsObject) = value else { return nil }
-        return Self.init(jsObject)
+        return Self(jsObject)
     }
 
     /** Creates a new `JSPromise` instance from a given `resolver` closure. `resolver` takes
-    two closure that your code should call to either resolve or reject this `JSPromise` instance.
-    */
-    public convenience init(resolver: @escaping (@escaping (Result<JSValue, JSValue>) -> ()) -> ()) {
+     two closure that your code should call to either resolve or reject this `JSPromise` instance.
+     */
+    public convenience init(resolver: @escaping (@escaping (Result<JSValue, JSValue>) -> Void) -> Void) {
         let closure = JSOneshotClosure { arguments in
             // The arguments are always coming from the `Promise` constructor, so we should be
             // safe to assume their type here
@@ -63,19 +63,19 @@ public final class JSPromise: JSBridgedClass {
             }
             return .undefined
         }
-        self.init(unsafelyWrapping: Self.constructor.new(closure))
+        self.init(unsafelyWrapping: Self.constructor!.new(closure))
     }
 
     public static func resolve(_ value: ConvertibleToJSValue) -> JSPromise {
-        self.init(unsafelyWrapping: Self.constructor.resolve!(value).object!)
+        self.init(unsafelyWrapping: Self.constructor!.resolve!(value).object!)
     }
 
     public static func reject(_ reason: ConvertibleToJSValue) -> JSPromise {
-        self.init(unsafelyWrapping: Self.constructor.reject!(reason).object!)
+        self.init(unsafelyWrapping: Self.constructor!.reject!(reason).object!)
     }
 
     /** Schedules the `success` closure to be invoked on sucessful completion of `self`.
-    */
+     */
     @discardableResult
     public func then(success: @escaping (JSValue) -> ConvertibleToJSValue) -> JSPromise {
         let closure = JSOneshotClosure {
@@ -85,10 +85,11 @@ public final class JSPromise: JSBridgedClass {
     }
 
     /** Schedules the `success` closure to be invoked on sucessful completion of `self`.
-    */
+     */
     @discardableResult
     public func then(success: @escaping (JSValue) -> ConvertibleToJSValue,
-                     failure: @escaping (JSValue) -> ConvertibleToJSValue) -> JSPromise {
+                     failure: @escaping (JSValue) -> ConvertibleToJSValue) -> JSPromise
+    {
         let successClosure = JSOneshotClosure {
             success($0[0]).jsValue
         }
@@ -99,7 +100,7 @@ public final class JSPromise: JSBridgedClass {
     }
 
     /** Schedules the `failure` closure to be invoked on rejected completion of `self`.
-    */
+     */
     @discardableResult
     public func `catch`(failure: @escaping (JSValue) -> ConvertibleToJSValue) -> JSPromise {
         let closure = JSOneshotClosure {
@@ -108,11 +109,11 @@ public final class JSPromise: JSBridgedClass {
         return .init(unsafelyWrapping: jsObject.catch!(closure).object!)
     }
 
-    /** Schedules the `failure` closure to be invoked on either successful or rejected completion of 
-    `self`.
-    */
+    /** Schedules the `failure` closure to be invoked on either successful or rejected completion of
+     `self`.
+     */
     @discardableResult
-    public func finally(successOrFailure: @escaping () -> ()) -> JSPromise {
+    public func finally(successOrFailure: @escaping () -> Void) -> JSPromise {
         let closure = JSOneshotClosure { _ in
             successOrFailure()
             return .undefined

Sources/JavaScriptKit/BasicObjects/JSTypedArray.swift

@@ -13,15 +13,15 @@ public protocol TypedArrayElement: ConvertibleToJSValue, ConstructibleFromJSValu
 /// A wrapper around all JavaScript [TypedArray](https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/TypedArray)
 /// classes that exposes their properties in a type-safe way.
 public class JSTypedArray<Element>: JSBridgedClass, ExpressibleByArrayLiteral where Element: TypedArrayElement {
-    public class var constructor: JSFunction { Element.typedArrayClass }
+    public class var constructor: JSFunction? { Element.typedArrayClass }
     public var jsObject: JSObject
 
     public subscript(_ index: Int) -> Element {
         get {
             return Element.construct(from: jsObject[index])!
         }
         set {
-            self.jsObject[index] = newValue.jsValue
+            jsObject[index] = newValue.jsValue
         }
     }
 
@@ -30,22 +30,23 @@ public class JSTypedArray<Element>: JSBridgedClass, ExpressibleByArrayLiteral wh
     ///
     /// - Parameter length: The number of elements that will be allocated.
     public init(length: Int) {
-        jsObject = Self.constructor.new(length)
+        jsObject = Self.constructor!.new(length)
     }
 
-    required public init(unsafelyWrapping jsObject: JSObject) {
+    public required init(unsafelyWrapping jsObject: JSObject) {
         self.jsObject = jsObject
     }
 
-    required public convenience init(arrayLiteral elements: Element...) {
+    public required convenience init(arrayLiteral elements: Element...) {
         self.init(elements)
     }
+
     /// Initialize a new instance of TypedArray in JavaScript environment with given elements.
     ///
     /// - Parameter array: The array that will be copied to create a new instance of TypedArray
     public convenience init(_ array: [Element]) {
         let jsArrayRef = array.withUnsafeBufferPointer { ptr in
-            _create_typed_array(Self.constructor.id, ptr.baseAddress!, Int32(array.count))
+            _create_typed_array(Self.constructor!.id, ptr.baseAddress!, Int32(array.count))
         }
         self.init(unsafelyWrapping: JSObject(id: jsArrayRef))
     }
@@ -80,7 +81,7 @@ public class JSTypedArray<Element>: JSBridgedClass, ExpressibleByArrayLiteral wh
         let rawBuffer = malloc(bytesLength)!
         defer { free(rawBuffer) }
         _load_typed_array(jsObject.id, rawBuffer.assumingMemoryBound(to: UInt8.self))
-        let length = lengthInBytes /  MemoryLayout<Element>.size
+        let length = lengthInBytes / MemoryLayout<Element>.size
         let boundPtr = rawBuffer.bindMemory(to: Element.self, capacity: length)
         let bufferPtr = UnsafeBufferPointer<Element>(start: boundPtr, count: length)
         let result = try body(bufferPtr)
@@ -105,6 +106,7 @@ extension Int: TypedArrayElement {
     public static var typedArrayClass: JSFunction =
         valueForBitWidth(typeName: "Int", bitWidth: Int.bitWidth, when32: JSObject.global.Int32Array).function!
 }
+
 extension UInt: TypedArrayElement {
     public static var typedArrayClass: JSFunction =
         valueForBitWidth(typeName: "UInt", bitWidth: Int.bitWidth, when32: JSObject.global.Uint32Array).function!
@@ -113,31 +115,35 @@ extension UInt: TypedArrayElement {
 extension Int8: TypedArrayElement {
     public static var typedArrayClass = JSObject.global.Int8Array.function!
 }
+
 extension UInt8: TypedArrayElement {
     public static var typedArrayClass = JSObject.global.Uint8Array.function!
 }
 
 public class JSUInt8ClampedArray: JSTypedArray<UInt8> {
-    public class override var constructor: JSFunction { JSObject.global.Uint8ClampedArray.function! }
+    override public class var constructor: JSFunction? { JSObject.global.Uint8ClampedArray.function! }
 }
 
 extension Int16: TypedArrayElement {
     public static var typedArrayClass = JSObject.global.Int16Array.function!
 }
+
 extension UInt16: TypedArrayElement {
     public static var typedArrayClass = JSObject.global.Uint16Array.function!
 }
 
 extension Int32: TypedArrayElement {
     public static var typedArrayClass = JSObject.global.Int32Array.function!
 }
+
 extension UInt32: TypedArrayElement {
     public static var typedArrayClass = JSObject.global.Uint32Array.function!
 }
 
 extension Float32: TypedArrayElement {
     public static var typedArrayClass = JSObject.global.Float32Array.function!
 }
+
 extension Float64: TypedArrayElement {
     public static var typedArrayClass = JSObject.global.Float64Array.function!
 }