crash when overriding native property

[farfromrefug]

here i override a native property. This makes it crash. You can reproduce it by the running the demo-vue here and going into dialogs and clicking on the first button

[darind]

Using the latest beta, in my case the app doesn't crash but it freezes when clicking on the Alert button. I am getting the following log:

2020-03-20 10:34:47.053793+0200 demovue[17827:1926802] Button touch target does not meet minimum size guidlines of (48, 48). Button: <MDCButton: 0x7faf06c329c0; baseClass = UIButton; frame = (10 460; 394 36); opaque = NO; layer = <MDCShapedShadowLayer: 0x60000276cf00>>, Touch Target: {394, 36}
2020-03-20 10:34:47.191630+0200 demovue[17827:1926802] CONSOLE LOG: onTap alert Button<alert>
2020-03-20 10:34:47.195892+0200 demovue[17827:1926802] CONSOLE LOG: showUIAlertController <MDCAlertControllerImpl: 0x7faf07853200> Page(38)

Other dialogs seem to work fine.

Are you getting some error log or a crash dump?

[farfromrefug]

Yes i am getting those logs too. For me on an ipjome 6 simulator running ios 12 it does a black screen right away. Buy i think it is the same for you. If it freezes i think it will eventually crash. I actually debugged this and got the breakpoint on the native call that was trying to acces the native property i am overriding. Let me know hiw i can help

[darind]

Can you try overriding the native property like this:

set preferredContentSize(x) {
    let proto = MDCAlertControllerImpl.prototype;
    Object.getOwnPropertyDescriptor(proto, "preferredContentSize").set.call(this, x);
}

I suspect that the issue might be related to the this.super usage causing a StackOverflow.

[farfromrefug]

As we discussed on stack the override you mentionned did not work

[farfromrefug]

@darind any chance you could look at this? My material components can't work without this

[darind]

@farfromrefug, sorry for the late reply. Can you try to replicate this issue in a simple javascript snippet? For example when I tried extending the following class I was able to successfully marshal the value between js and native:

const MDCAlertControllerImpl = UIViewController.extend({
    get preferredContentSize() {
        const superResult = this.super.preferredContentSize;
        return superResult;
    },
    set preferredContentSize(x) {
        this.super.preferredContentSize = x;
    }
});

I am then able to instantiate and use this class:

var instance = new MDCAlertControllerImpl();
instance.preferredContentSize = CGSizeMake(173, 245);
Foo.test(instance);

where I have defined the custom Foo native class:

@interface Foo : NSObject

+(void)test:(UIViewController*)o;

@end

@implementation Foo

+(void)test:(UIViewController*)o {
    CGSize sz = [o preferredContentSize];
    NSLog(@"%fx%f", sz.width, sz.height);
}

@end

This prints the expected 173.000000x245.000000 message to the console.

[farfromrefug]

@darind thanks for your answer. Won't be able to do it in the next 3 weeks. When I ll come back I ll test it again but I think the demo vue of my nativescript-material-components shows it in the dialog section. If not it must have been fixed

[farfromrefug]

@darind @NathanWalker that bug is still present. Just tried it again and it is still crashing. tested with 7.0.0-beta.3-v8-2020-07-01-222820-05 Again the demo-vue app crashes in the dialogs sample while clicking on the first button. Can it be related to the super class MDCAlertController ?

[farfromrefug]

To add to this, with the migration to n 7 i made some more tests. If i change that class to es6 with @NativeClass i get a different error

====== Assertion failed ======
Native stack trace:
1          0x10f257ceb tns::Assert(bool, v8::Isolate*) + 119
2          0x10f1c7079 tns::ArgConverter::Invoke(v8::Local<v8::Context>, objc_class*, v8::Local<v8::Object>, tns::V8Args&, tns::MethodMeta const*, bool) + 95
3          0x10f21f83a tns::MetadataBuilder::InvokeMethod(v8::Local<v8::Context>, tns::MethodMeta const*, v8::Local<v8::Object>, tns::V8Args&, std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> >, bool) + 76
4          0x10f21f4a1 tns::MetadataBuilder::PropertySetterCallback(v8::FunctionCallbackInfo<v8::Value> const&) + 249
5          0x10f38f22c v8::internal::FunctionCallbackArguments::Call(v8::internal::CallHandlerInfo) + 620
6          0x10f38e6dc v8::internal::MaybeHandle<v8::internal::Object> v8::internal::(anonymous namespace)::HandleApiCallHelper<false>(v8::internal::Isolate*, v8::internal::Handle<v8::internal::HeapObject>, v8::internal::Handle<v8::internal::HeapObject>, v8::internal::Handle<v8::internal::FunctionTemplateInfo>, v8::internal::Handle<v8::internal::Object>, v8::internal::BuiltinArguments) + 556
7          0x10f38e084 v8::internal::Builtins::InvokeApiFunction(v8::internal::Isolate*, bool, v8::internal::Handle<v8::internal::HeapObject>, v8::internal::Handle<v8::internal::Object>, int, v8::internal::Handle<v8::internal::Object>*, v8::internal::Handle<v8::internal::HeapObject>) + 692
8          0x10f73018f v8::internal::Object::SetPropertyWithAccessor(v8::internal::LookupIterator*, v8::internal::Handle<v8::internal::Object>, v8::Maybe<v8::internal::ShouldThrow>) + 511
9          0x10f7353b6 v8::internal::Object::SetPropertyInternal(v8::internal::LookupIterator*, v8::internal::Handle<v8::internal::Object>, v8::Maybe<v8::internal::ShouldThrow>, v8::internal::StoreOrigin, bool*) + 358
10         0x10f735196 v8::internal::Object::SetProperty(v8::internal::LookupIterator*, v8::internal::Handle<v8::internal::Object>, v8::internal::StoreOrigin, v8::Maybe<v8::internal::ShouldThrow>) + 54
11         0x10f59601d v8::internal::StoreIC::Store(v8::internal::Handle<v8::internal::Object>, v8::internal::Handle<v8::internal::Name>, v8::internal::Handle<v8::internal::Object>, v8::internal::StoreOrigin) + 1053
12         0x10f59b2dd v8::internal::Runtime_StoreIC_Miss(int, unsigned long*, v8::internal::Isolate*) + 413
13         0x10fc26c39 Builtins_CEntry_Return1_DontSaveFPRegs_ArgvOnStack_NoBuiltinExit + 57
JavaScript stack trace:
at set (file:///app/bundle.js:2320:45)
at MDCAlertControllerImpl.viewDidLoad (file:///app/bundle.js:2491:34)
at showUIAlertController (file: app/src/dialogs.ios.ts:716:27

Which seems to come from that line https://github.com/NativeScript/ns-v8ios-runtime/blob/59ae25d79497a73b86b7a35ec4ad0b4f3507b4f2/NativeScript/runtime/ArgConverter.mm#L29 or maybe this one (the stack does not tell me really) https://github.com/NativeScript/ns-v8ios-runtime/blob/59ae25d79497a73b86b7a35ec4ad0b4f3507b4f2/NativeScript/runtime/ArgConverter.mm#L45

Also .extend does work with the older runtime but es6 class transformer to es5 with @NativeClass does not either