Unable to use more than one type argument

[ctron]

Problem

Using more than one type argument in a component results in the follow error message during compilation:

error: expected a valid html element
  --> src/components/tabs.1.example:10:5
   |
10 |     </TabsRouter<crate::AppRoute, TabRoutes>>
   |     ^
   |
   = note: this error originates in a macro (in Nightly builds, run with -Z macro-backtrace for more info)

Steps To Reproduce

Create a component with more than one type argument.

Expected behavior

I would expect this to work, like with a single type argument.

Workaround

There is a workaround, you can define a type alias and use this instead:

type MyTabRouter = TabRouter<Foo,Bar>;

And then:

html![
  <MyTabRouter />
}

Environment:

• Yew version: 0.17, 0.18
• Rust version: 1.51

Questionnaire

• I'm interested in fixing this myself but don't know where to start
• I would like to fix and I have a solution
• I don't have time to fix this right now, but maybe later

[lukechu10]

Hmm, I thought I fixed this in #1738. There even is a trybuild test here:

yew/packages/yew-macro/tests/html_macro/generic-component-pass.rs

Lines 57 to 73 in 3180fc7

	fn compile_pass() {
	html! { <Generic<String> /> };
	html! { <Generic<String> ></Generic<String>> };
	html! { <Generic<Vec<String>> /> };
	html! { <Generic<Vec<String>>></ Generic<Vec<String>>> };
	html! { <Generic<usize> /> };
	html! { <Generic<usize>></Generic<usize>> };
	html! { <Generic<String, > /> };
	html! { <Generic<String, >></Generic<String,>> };
	html! { <Generic2<String, String> /> };
	html! { <Generic2<String, String>></Generic2<String, String>> };
	html! { <Generic2<String, String, > /> };
	html! { <Generic2<String, String, >></Generic2<String, String, >> };

Edit: Maybe it's because of the crate::AppRoute? If you add use crate::AppRoute and just use TabRouter<AppRouter, TabRoutes>, does it work?

[ctron]

Nope, I tried that at well. Didn't work.

[ctron]

Ah, it might be that I accidentally did not properly test with 0.18, only with 0.17. I will re-test that.

[ctron]

Ok, I am confused now. The code you have seems to be on "master", but not in "0.18". Although the changes older than the "0.18" release.

Anyway, I think it needs a bit more fixing :) It looks to me as if this only is a problem for the closing tag:

pub fn test() {
    // works
    let _foo = html! {
        <Foo<String,String>/>
    };
    // fails
    let _foo = html! {
        <Foo<String,String>>
        </Foo<String,String>>
    };
}

[ctron]

And, it fails with both 0.17 and 0.18.

[lukechu10]

Ok, I am confused now. The code you have seems to be on "master", but not in "0.18". Although the changes older than the "0.18" release.

The commit probably didn't get cherry-picked onto the 0.18 release. Not sure why but you probably need to use a git dependency on master for now.

Also the second code snippet that fails should also work on master. It's identical to the trybuild test.

[ctron]

Ok, I am confused now. The code you have seems to be on "master", but not in "0.18". Although the changes older than the "0.18" release.

The commit probably didn't get cherry-picked onto the 0.18 release. Not sure why but you probably need to use a git dependency on master for now.

Ok, this is confusing. Especially as the version on master is still "0.17"!

Also the second code snippet that fails should also work on master. It's identical to the trybuild test.

I tried that with master, and indeed that works.

[ctron]

@lukechu10 is there any date when the new release can be expected?

[lukechu10]

Unfortunately I don't have any idea. I saw you on the discord server so maybe try asking there?