From 987f8b8f0045c7d924672d7514cb61cd08e6e827 Mon Sep 17 00:00:00 2001
From: TopchetoEU <36534413+TopchetoEU@users.noreply.github.com>
Date: Sat, 25 Nov 2023 14:18:46 +0200
Subject: [PATCH] fix: handle native errors properly-ish

---
 .../interop/NativeWrapperProvider.java        | 37 ++++++++++++++-----
 .../jscript/interop/OverloadFunction.java     | 10 ++++-
 2 files changed, 37 insertions(+), 10 deletions(-)

diff --git a/src/me/topchetoeu/jscript/interop/NativeWrapperProvider.java b/src/me/topchetoeu/jscript/interop/NativeWrapperProvider.java
index 11f7a61..6edc93f 100644
--- a/src/me/topchetoeu/jscript/interop/NativeWrapperProvider.java
+++ b/src/me/topchetoeu/jscript/interop/NativeWrapperProvider.java
@@ -108,6 +108,12 @@ public class NativeWrapperProvider implements WrappersProvider {
         }
     }
 
+    public static String getName(Class<?> clazz) {
+        var classNat = clazz.getAnnotation(Native.class);
+        if (classNat != null && !classNat.value().trim().equals("")) return classNat.value().trim();
+        else return clazz.getSimpleName();
+    }
+
     /**
      * Generates a prototype for the given class.
      * The returned object will have appropriate wrappers for all instance members.
@@ -117,10 +123,7 @@ public class NativeWrapperProvider implements WrappersProvider {
     public static ObjectValue makeProto(Environment ctx, Class<?> clazz) {
         var res = new ObjectValue();
 
-        var name = clazz.getName();
-        var classNat = clazz.getAnnotation(Native.class);
-        if (classNat != null && !classNat.value().trim().equals("")) name = classNat.value().trim();
-        res.defineProperty(null, ctx.symbol("Symbol.typeName"), name);
+        res.defineProperty(null, ctx.symbol("Symbol.typeName"), getName(clazz));
 
         for (var overload : clazz.getDeclaredMethods()) {
             var init = overload.getAnnotation(NativeInit.class);
@@ -142,11 +145,7 @@ public class NativeWrapperProvider implements WrappersProvider {
      * @param clazz The class for which a constructor should be generated
      */
     public static FunctionValue makeConstructor(Environment ctx, Class<?> clazz) {
-        var name = clazz.getName();
-        var classNat = clazz.getAnnotation(Native.class);
-        if (classNat != null && !classNat.value().trim().equals("")) name = classNat.value().trim();
-
-        FunctionValue func = new OverloadFunction(name);
+        FunctionValue func = new OverloadFunction(getName(clazz));
 
         for (var overload : clazz.getDeclaredConstructors()) {
             var nat = overload.getAnnotation(Native.class);
@@ -261,7 +260,27 @@ public class NativeWrapperProvider implements WrappersProvider {
         constructors.put(clazz, value);
     }
 
+    private void initError() {
+        var proto = new ObjectValue();
+        proto.defineProperty(null, "message", new NativeFunction("message", (ctx, thisArg, args) -> {
+            if (thisArg instanceof Throwable) return ((Throwable)thisArg).getMessage();
+            else return null;
+        }));
+        proto.defineProperty(null, "name", new NativeFunction("name", (ctx, thisArg, args) -> getName(thisArg.getClass())));
+
+        var constr = makeConstructor(null, Throwable.class);
+        proto.defineProperty(null, "constructor", constr, true, false, false);
+        constr.defineProperty(null, "prototype", proto, true, false, false);
+
+        proto.setPrototype(null, getProto(Object.class));
+        constr.setPrototype(null, getConstr(Object.class));
+
+        setProto(Throwable.class, proto);
+        setConstr(Throwable.class, constr);
+    }
+
     public NativeWrapperProvider(Environment env) {
         this.env = env;
+        initError();
     }
 }
diff --git a/src/me/topchetoeu/jscript/interop/OverloadFunction.java b/src/me/topchetoeu/jscript/interop/OverloadFunction.java
index ee0470a..9edd2a5 100644
--- a/src/me/topchetoeu/jscript/interop/OverloadFunction.java
+++ b/src/me/topchetoeu/jscript/interop/OverloadFunction.java
@@ -8,6 +8,7 @@ import java.util.List;
 import me.topchetoeu.jscript.Location;
 import me.topchetoeu.jscript.engine.Context;
 import me.topchetoeu.jscript.engine.values.FunctionValue;
+import me.topchetoeu.jscript.engine.values.NativeWrapper;
 import me.topchetoeu.jscript.engine.values.Values;
 import me.topchetoeu.jscript.exceptions.ConvertException;
 import me.topchetoeu.jscript.exceptions.EngineException;
@@ -92,7 +93,14 @@ public class OverloadFunction extends FunctionValue {
                     throw new InterruptException();
                 }
                 else {
-                    throw EngineException.ofError(e.getTargetException().getMessage()).add(name, loc);
+                    var target = e.getTargetException();
+                    var targetClass = target.getClass();
+                    var err = new NativeWrapper(e.getTargetException());
+
+                    err.defineProperty(ctx, "message", target.getMessage());
+                    err.defineProperty(ctx, "name", NativeWrapperProvider.getName(targetClass));
+
+                    throw new EngineException(err).add(name, loc);
                 }
             }
             catch (ReflectiveOperationException e) {