Narrows type of parent in render functions.

[MicahZoltu]

https://gist.github.com/developit/f4c67a2ede71dc2fab7f357f39cff28c is the recommended way to partial root rendering in Preact 10+, but it isn't API compliant code given the current API definition as expressed by the TS types. This PR changes the type of parent to align with what is actually required by the preact render functions according to @developit.

Assuming the linked code actually works, then it means preact doesn't actually need a NodeList, but rather just needs an ArrayLike<Node>. Along with limiting the property set of Parent, I have also narrowed Parent['childNodes'] to be an ArrayLike<Node> so someone can assign a Node[] to it.

I suspect my stylistic choice of a single long line is not acceptable for this repository, but I'm not clear what the proper way to break this into multiple lines is for this repository. If someone can provide me with feedback on how to correctly split the lines, please let me know!

Note: I recognize that this is a pretty substantial type change, but without it the official recommendation (and only option in Preact 11) for doing partial root rendering is incorrect. Either the recommendation for how to do partial root rendering should be corrected to not lead people to an incorrect solution, or this PR (or one like it) should be merged to correctly express the type that preact expects for its render functions.

[andrewiggins]

Would it work if instead you did something like:

interface ContainerNode {
  nodeType: Node['nodeType'];
  parentNode: Node['nodeType'];
  firstChild: Node['firstchild'];
  insertBefore: Node['insertBefore'];
  appendChild: Node['appendChild'];
  removeChild: Node['removeChild'];
  childNodes: ArrayLike<Node>
}

I find this a bit easier to read and my understanding is that all the types (Element | Document | ShadowRoot | .. etc) already implement this interface so it should work?

[MicahZoltu]

I just checked on this and you are correct that all of these properties come from Node, so what you have proposed would work. I'll make this change to the PR.

[MicahZoltu]

Applied the change. Let me know if there are other things I should change!

[coveralls]

Coverage: 99.531%. Remained the same when pulling f91827b on MicahZoltu:patch-1 into c483d96 on preactjs:master.

[MicahZoltu]

Hmm, the recent change proposed by @andrewiggins seems to have caused the tests to not compile, which surprises me a bit. I double checked the properties prior to applying the change and it looked like the types matched on all of them. I'll try to take a look at this and figure out why the tests are failing to compile.

Error: test/ts/preact.tsx(58,59): error TS2769: No overload matches this call.
  Overload 1 of 2, '(vnode: ComponentChild, parent: ContainerNode): void', gave the following error.
    Argument of type 'Document' is not assignable to parameter of type 'ContainerNode'.
      Types of property 'parentNode' are incompatible.
        Type 'ParentNode | null' is not assignable to type 'number'.
          Type 'null' is not assignable to type 'number'.
  Overload 2 of 2, '(vnode: ComponentChild, parent: ContainerNode, replaceNode?: Element | Text | undefined): void', gave the following error.
    Argument of type 'Document' is not assignable to parameter of type 'ContainerNode'.
Error: test/ts/preact.tsx(61,2): error TS2769: No overload matches this call.
  Overload 1 of 2, '(vnode: ComponentChild, parent: ContainerNode): void', gave the following error.
    Argument of type 'Document' is not assignable to parameter of type 'ContainerNode'.
  Overload 2 of 2, '(vnode: ComponentChild, parent: ContainerNode, replaceNode?: Element | Text | undefined): void', gave the following error.
    Argument of type 'Document' is not assignable to parameter of type 'ContainerNode'.
Error: test/ts/preact.tsx(69,2): error TS2769: No overload matches this call.
  Overload 1 of 2, '(vnode: ComponentChild, parent: ContainerNode): void', gave the following error.
    Argument of type 'Document' is not assignable to parameter of type 'ContainerNode'.
  Overload 2 of 2, '(vnode: ComponentChild, parent: ContainerNode, replaceNode?: Element | Text | undefined): void', gave the following error.
    Argument of type 'Document' is not assignable to parameter of type 'ContainerNode'.
Error: test/ts/preact.tsx(71,47): error TS2769: No overload matches this call.
  Overload 1 of 2, '(vnode: ComponentChild, parent: ContainerNode): void', gave the following error.
    Argument of type 'Document' is not assignable to parameter of type 'ContainerNode'.
  Overload 2 of 2, '(vnode: ComponentChild, parent: ContainerNode, replaceNode?: Element | Text | undefined): void', gave the following error.
    Argument of type 'Document' is not assignable to parameter of type 'ContainerNode'.
Error: test/ts/preact.tsx(72,68): error TS2769: No overload matches this call.
  Overload 1 of 2, '(vnode: ComponentChild, parent: ContainerNode): void', gave the following error.
    Argument of type 'Document' is not assignable to parameter of type 'ContainerNode'.
  Overload 2 of 2, '(vnode: ComponentChild, parent: ContainerNode, replaceNode?: Element | Text | undefined): void', gave the following error.
    Argument of type 'Document' is not assignable to parameter of type 'ContainerNode'.
Error: test/ts/preact.tsx(79,2): error TS2769: No overload matches this call.
  Overload 1 of 2, '(vnode: ComponentChild, parent: ContainerNode): void', gave the following error.
    Argument of type 'Document' is not assignable to parameter of type 'ContainerNode'.
  Overload 2 of 2, '(vnode: ComponentChild, parent: ContainerNode, replaceNode?: Element | Text | undefined): void', gave the following error.
    Argument of type 'Document' is not assignable to parameter of type 'ContainerNode'.

[andrewiggins]

Thanks for the update! Looks like we are close :)

[andrewiggins]

Looks good! Thank you <3