What OS are you using (uname -a, or Windows version)?

MacOS

What programming language are you using (C/C++/Go/Rust)?

go version go1.12.10 darwin/amd64

What did you expect to see and what you saw instead?

Using SetSize I expected the window to resize and keep it's position. Instead it resized to the right size but went to position 0,0.

In webview.h the code is set to specifically align the the view to 0,0 and set the new size.

objc_msgSend(m_window, "setFrame:display:animate:"_sel,
                   CGRectMake(0, 0, width, height), 1, 0);

The call to CGRectMake(0, 0, width, height) should really be something like CGRectMake(frame.origin.x, frame.origin.y, width, height). Unfortunately I don't quite understand the code well enough to get the frame object, although I have found all the relevant objective C docs and stack overflows:

https://developer.apple.com/documentation/appkit/nswindow/1419697-frame
https://stackoverflow.com/questions/12438224/set-nswindow-size-programmatically

I believe the only thing missing is getting the window's frame and then you can either set the width and height of that or use the x and y in the new frame. If anyone knows how to do this or where to point me so I can figure it out, I'm willing to make a PR for it but I don't have all week to figure this out and I assume its rather trivial if you know what you're doing (or maybe not)