(feat) infer slot/events type from props

[dummdidumm]

This changes the generation for accessing the events/slots of a component. Instead of using instanceOf, the component instance is created using the constructor and passing the props. This enables TypeScript to infer generic relationships between props and slots/events.
#945
Note that this change does not cover all cases: If someone forwards a slot or an event whose type is generic and needs to be infered, that type will remain unknown, because reinstantiating the context in the return { props: .. } step is really hard.

TODO:
How to fix the "varialbe used before instantiation"-error that occurs when we tranform <Foo prop={prop} let:prop>? The transformation for let:prop is const prop = new Foo({.. props: {prop: prop}}) which TS doesn't like. @jasonlyu123 any ideas?

[jasonlyu123]

The only solution I can think of now is to declare a new variable. Something similar to if-scope or pass it as a parameter to an immediately invoked function.

const __propsArgs = { a }
() =>{  
  const a = new Component({ props: __propsArgs  }).$$slotdef['default']
}

or

((__propsArgs) =>{  
  const a = new Component({ props: __propsArgs  }).$$slotdef['default']
})({ a })

[dummdidumm]

Yeah sounds like the only option. So there needs to be some logic to track which props there are both on the default and the names slots, and if there's one that's duplicated, construct a immediately invoked function from the default slot and reuse that in all the inner slots.
Edit: Just had the idea, we could reuse the ifScope-redeclare-for-control-flow-logic here.

[dummdidumm]

Ok I reused the ifScope logic here, worked out well, although I still feel that this code is getting more and more complex - if it's just inevitable or I'm writing shitty code, can't tell for sure right now 😄 @jasonlyu123 could you have a look?

[jasonlyu123]

Mostly working great. Found a small problem when an attribute is empty. And some minor issues to discuss.

[dummdidumm]

These were great suggestions, thanks! Especially that string template comment was a moment of enlightment 😄

[ryu-man]

I noticed that a string value is inferred as "any" type in the slot prop!

[dummdidumm]

Should be fixed with the latest release

[ryu-man]

I am using the latest release, all values get inferred normally, but when using a string value it inferred as "any" type not "string" type

[dummdidumm]

Can't reproduce. What's your version? Latest is 104.10.1 . If the issue persists with the latest version after restarting VS Code, please open a separate issue with detailed instructions.

[ryu-man]

Great, I tried that one more time and it's working fine now.