Merge #640

640: fix #638 r=jstarry a=astraw

This fixes #638.

So far, I was not able to the test suite to run, so I wasn't able to write a test for this.

Co-authored-by: Andrew Straw <strawman@astraw.com>
Co-authored-by: Justin Starry <jstarry@users.noreply.github.com>

crates/macro/src/derive_props/builder.rs

@@ -64,7 +64,9 @@ impl ToTokens for PropsBuilder<'_> {
             #(impl #step_trait for #step_names {})*
 
             #[doc(hidden)]
-            #vis struct #builder_name#step_generics {
+            #vis struct #builder_name#step_generics
+                #where_clause
+            {
                 wrapped: ::std::boxed::Box<#wrapper_name#ty_generics>,
                 _marker: ::std::marker::PhantomData<#step_generic_param>,
             }

crates/macro/src/derive_props/wrapper.rs

@@ -24,7 +24,9 @@ impl ToTokens for PropsWrapper<'_> {
         let wrapper_default_setters = self.default_setters();
 
         let wrapper = quote! {
-            struct #wrapper_name#generics {
+            struct #wrapper_name#generics
+                #where_clause
+            {
                 #(#wrapper_field_defs)*
             }
 

tests/derive_props/pass.rs

@@ -83,4 +83,22 @@ mod t5 {
     }
 }
 
+mod t6 {
+    use super::*;
+    use std::str::FromStr;
+
+    #[derive(Properties, Clone)]
+    pub struct Props<T: FromStr + Clone>
+    where
+    <T as FromStr>::Err: Clone,
+    {
+        #[props(required)]
+        value: Result<T, <T as FromStr>::Err>,
+    }
+
+    fn required_prop_generics_with_where_clause_should_work() {
+        Props::<String>::builder().value(Ok(String::from(""))).build();
+    }
+}
+
 fn main() {}