async JSPromise callbacks

Author: j-f1

Sources/JavaScriptKit/BasicObjects/JSPromise.swift

@@ -75,6 +75,15 @@ public final class JSPromise: JSBridgedClass {
         return JSPromise(unsafelyWrapping: jsObject.then!(closure).object!)
     }
 
+    /// Schedules the `success` closure to be invoked on successful completion of `self`.
+    @discardableResult
+    public func then(success: @escaping (JSValue) async -> ConvertibleToJSValue) -> JSPromise {
+        let closure = JSOneshotClosure.async {
+            return await success($0[0]).jsValue()
+        }
+        return JSPromise(unsafelyWrapping: jsObject.then!(closure).object!)
+    }
+
     /// Schedules the `success` closure to be invoked on successful completion of `self`.
     @discardableResult
     public func then(success: @escaping (JSValue) -> ConvertibleToJSValue,
@@ -88,6 +97,19 @@ public final class JSPromise: JSBridgedClass {
         return JSPromise(unsafelyWrapping: jsObject.then!(successClosure, failureClosure).object!)
     }
 
+    /// Schedules the `success` closure to be invoked on successful completion of `self`.
+    @discardableResult
+    public func then(success: @escaping (JSValue) async -> ConvertibleToJSValue,
+                     failure: @escaping (JSValue) async -> ConvertibleToJSValue) -> JSPromise {
+        let successClosure = JSOneshotClosure.async {
+            return await success($0[0]).jsValue()
+        }
+        let failureClosure = JSOneshotClosure.async {
+            return await failure($0[0]).jsValue()
+        }
+        return JSPromise(unsafelyWrapping: jsObject.then!(successClosure, failureClosure).object!)
+    }
+
     /// Schedules the `failure` closure to be invoked on rejected completion of `self`.
     @discardableResult
     public func `catch`(failure: @escaping (JSValue) -> ConvertibleToJSValue) -> JSPromise {
@@ -97,6 +119,15 @@ public final class JSPromise: JSBridgedClass {
         return .init(unsafelyWrapping: jsObject.catch!(closure).object!)
     }
 
+    /// Schedules the `failure` closure to be invoked on rejected completion of `self`.
+    @discardableResult
+    public func `catch`(failure: @escaping (JSValue) async -> ConvertibleToJSValue) -> JSPromise {
+        let closure = JSOneshotClosure.async {
+            return await failure($0[0]).jsValue()
+        }
+        return .init(unsafelyWrapping: jsObject.catch!(closure).object!)
+    }
+
     /// Schedules the `failure` closure to be invoked on either successful or rejected
     /// completion of `self`.
     @discardableResult