NSDictionary and golang strings issue about macdriver

[progrium]

All strings need to ultimately be wrapped with core.String(), so that should help here. I think the idea was the manual bindings would do this for you, but when it takes arguments of any type here we can't do that. Well, we could have a function do a type switch and convert...

[programmingkidx]

Ok I tried wrapping the strings but I still see an error. Here is the program I made:

package main

import "github.com/progrium/macdriver/core"
import "fmt"

func main() {
	oneStr := core.String("one")
	twoStr := core.String("two")
	dict := core.NSDictionary_Init(oneStr, twoStr, nil)
	fmt.Println("dictionary:", dict)
}

When I run it I see this error:

2023-07-02 08:05:48.788 main[1459:20783] *** Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '-[__NSPlaceholderDictionary initWithObjectsAndKeys:]: second object of each pair must be non-nil. Or, did you forget to nil-terminate your parameter list?'
*** First throw call stack:
(
0 CoreFoundation 0x00000001bf532b08 __exceptionPreprocess + 240
1 libobjc.A.dylib 0x00000001bf27de14 objc_exception_throw + 60
2 CoreFoundation 0x00000001bf476764 -[NSDictionary initWithObjectsAndKeys:] + 792
3 main 0x0000000104a16960 VariadicCall + 96
4 ??? 0x000001400011c750 0x0 + 1374390699856
)
libc++abi: terminating with uncaught exception of type NSException
SIGABRT: abort
PC=0x1bf3b0db8 m=0 sigcode=0
signal arrived during cgo execution

Did I do something wrong?

[progrium]

Hmm... not sure it's you. Could be related to not supporting Golang nil. Could be related to variadic calls. Also raises the issue that at least the core/foundation code should probably have some tests.

[progrium]

Can you try the equivalent of this using darwinkit or in main when this PR is merged:
#176

[programmingkidx]

Well I did try to but I ran into a few problem. There are no NSDictionary Init() or dictionaryWithObjectsAndKeys() methods. Not sure how to create an NSDictionary object.

[progrium]

https://pkg.go.dev/github.com/progrium/[email protected]/macos/foundation#NewDictionary
https://pkg.go.dev/github.com/progrium/[email protected]/macos/foundation#Dictionary_DictionaryWithObjectsAndKeys

But it looks like we don't support variadic methods! Making a separate issue: #181

[progrium]

It should work with the latest PR, though the first object still has to be an IObject, however there are some custom helpers for more easily building NSDictionaries from Go maps. There is now a test case that demonstrates all of this, which I'll include here:

func TestFoundationDictionary(t *testing.T) {
	s := String_StringWithString("bar")
	d1 := Dictionary_DictionaryWithObjectsAndKeys(s, "foo", "value", "key", nil)
	m1 := DictToMap[string, string](d1)
	d2 := DictOf(m1)
	m2 := DictToMap[string, string](d2)
	if !reflect.DeepEqual(m2, map[string]string{
		"foo": "bar",
		"key": "value",
	}) {
		t.Fatal("unexpected final map from dictionary")
	}
}

[progrium]

Closing since there are tests passing that satisfy the original issue. Please open another issue or discussion if there is still a problem or question.