Improve component trait check

yewstack · Jul 21, 2019 · 9781884 · 9781884
1 parent b98d557
commit 9781884
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Showing 3 changed files with 7 additions and 3 deletions.
diff --git a/crates/macro/src/html_tree/html_component.rs b/crates/macro/src/html_tree/html_component.rs
@@ -101,7 +101,12 @@ impl ToTokens for HtmlComponent {
         };
 
         let validate_comp = quote_spanned! { ty.span()=>
-            struct __yew_validate_comp where #ty: ::yew::html::Component;
+            trait __yew_validate_comp {
+                type C: ::yew::html::Component;
+            }
+            impl __yew_validate_comp for () {
+                type C = #ty;
+            }
         };
 
         tokens.extend(quote! {{

diff --git a/tests/macro/html-component-fail-unimplemented.stderr b/tests/macro/html-component-fail-unimplemented.stderr
@@ -3,7 +3,5 @@ error[E0277]: the trait bound `std::string::String: yew::html::Component` is not
   |
 6 |     html! { <String /> };
   |              ^^^^^^ the trait `yew::html::Component` is not implemented for `std::string::String`
-  |
-  = help: see issue #48214
 
 For more information about this error, try `rustc --explain E0277`.
diff --git a/tests/macro_test.rs b/tests/macro_test.rs
@@ -8,6 +8,7 @@ fn tests() {
 
     t.pass("tests/macro/html-component-pass.rs");
     t.compile_fail("tests/macro/html-component-fail.rs");
+    t.compile_fail("tests/macro/html-component-fail-unimplemented.rs");
 
     t.pass("tests/macro/html-iterable-pass.rs");
     t.compile_fail("tests/macro/html-iterable-fail.rs");