Implement isObject & object properties

Author: tonyfreeman

Sources/JavaScript/JSValue.swift

@@ -69,6 +69,26 @@ extension JSValue {
     }
 }
 
+extension JSValue {
+    subscript(_ property: String) -> JSValue? {
+        guard isObject else {
+            return nil
+        }
+        let bytes = [UInt16](property.utf16)
+        let property = JSStringCreateWithCharacters(bytes, bytes.count)
+        defer { JSStringRelease(property) }
+
+        var exception: JSValueRef? = nil
+        let result = JSObjectGetProperty(context, pointer, property, &exception)
+
+        if exception != nil {
+            return nil
+        }
+        return JSValue(context: context, pointer: result!)
+    }
+}
+
+
 extension JSValue {
     public var isNull: Bool {
         return JSValueIsNull(context, pointer)
@@ -89,6 +109,10 @@ extension JSValue {
     public var isString: Bool {
         return JSValueIsString(context, pointer)
     }
+
+    public var isObject: Bool {
+        return JSValueIsObject(context, pointer)
+    }
 }
 
 extension JSValue {

Tests/JavaScriptTests/JSValueTests.swift

@@ -31,4 +31,20 @@ final class JSValueTests: TestCase {
             fail(String(describing: error))
         }
     }
+
+    func testProperty() {
+        do {
+            let context = JSContext()
+            let result = try context.evaluate("""
+                (function(){
+                    return { property: 'test' }
+                })()
+                """)
+
+            print(result)
+            assertEqual(try result["property"]?.toString(), "test")
+        } catch {
+            fail(String(describing: error))
+        }
+    }
 }