[fix] scoped slot typing

[blake-newman]

• Update vue dependencies
• Fix scoped slots definitions to be compatible with Vue typings
• ScopedSlots can be undefined as there is no guarantee that the scoped
  slot has to be passed. vuejs/vue@448ba65
• Fixes Improve ScopedSlot type #11

[chanlito]

Hey @blake-newman just out of curiosity which version of typescript are you on?

[blake-newman]

This will be the latest version 3.1.2 for our projects.

This project uses: https://github.com/wonderful-panda/vue-tsx-support/blob/master/package.json#L56

[wonderful-panda]

I don't want to make all scoped slots optional unconditionally.

I think it would be better that optional slots are marked explicitly like below.

export interface MyScopedSlots {
  foo?: string;  // optional
  bar: string; // required
}

export const MyComponent = tsx.componentFactoryOf<{}, MyScopedSlots>().create({
  render(): VNode {
    const { foo, bar } = this.$scopedSlots;
    return (
      <div>
        { foo ? foo("foo") : "default foo" }
        { bar("bar") }
      </div>
    );
  }
});

[blake-newman]

That makes sense, aslong as the usage (<Component scopedSlots={{...}} />) enforces that scoped slots must be passed if declared. This way you can't run into a runtime error with scoped slots.

Do you know if this is currently the case? I will amend this PR to make the typing more strict.

[wonderful-panda]

@blake-newman
Sorry for the late response.

Currently vue-tsx-support enforces to specify all declared scoped slots as you said.
Vue itself allows scoped slots to be omitted.
It would be nice that vue-tsx-support can support scoped slots omitting, but I don't want to spoil current type-safety to support it.

BTW, I pushed and published as v2.2.2 related change to fix #18, (7f277c8). Vue 2.5.13 is still supported.
I don't think we must support Vue 2.5.13, it is old enough, but I think we should support not only Vue 2.5.21 (newest), but also several older versions as possible.