fix: vNext `fast-router` templates not attaching on safari 16+

[KingOfTac]

🐛 Bug Report

There appears to be an issue with the latest version of webkit that is causing Router to not get a template. Currently not aware if this is an issue with the vCurrent version of Router.

💻 Repro or Code Sample

Working on a repro.

Simple repro steps would be to create a new project using the latest FAST prerelease versions and add router with a few routes and a default layout.

🤔 Expected Behavior

Apps that use Router should be loading properly

😯 Current Behavior

After safari 16 was released, Router no longer gets a template attached either on initial page load or on route changes. Other FAST components built using the vNext libraries function normally.

💁 Possible Solution

Needs investigation

🌍 Your Environment

Safari on IOS 16.1
Epiphany Browser using webkit 16 on WSL Ubuntu-latest in windows 11

[KingOfTac]

@EisenbergEffect I think I discovered the issue here, but not sure if it is an indication of a larger issue.

I noticed in my debugging that the DefaultRouter's config setter was not getting called in safari16. In the web component template that hosts the router element, I am binding the route config through a property binding: <fast-router :config=${x => x.config}>. I moved the setting of Router's config to the parent component's connectedCallback and things started working normally. What is really confusing is that the issue is only happening in Safari16+, all other browsers including Safari<16 are working fine with setting the router's config through a property binding in the template.

[EisenbergEffect]

That's very strange. Can you isolate the issue to a simple component without the router?

[KingOfTac]

That's very strange. Can you isolate the issue to a simple component without the router?

I've been working on isolating, but no luck yet. It may also be a combination of things since I am using the inject decorator to inject the router config into the router's parent component.

[KingOfTac]

@EisenbergEffect I haven't been able to create a reliable repro yet, but seems like something changed in webkit16+ that is causing DI to break in some scenarios. I no longer think that this is an issue with Router, and instead it is in DI. I also don't think it is an issue with FAST at all but a bug introduced in Webkit since prior to 16 everything worked fine.

[bigopon]

Recently Aurelia has also been hit by some issues from webkit 16+. The issue is at aurelia/framework#1003

There's a breaking change in the spec at whatwg/dom#754, @jded76 and I have been trying to get a spec revert, and are waiting for some responses. You can join the discussion at whatwg/dom#819 (comment)