Implement HtmlSafe for all reference wrappers

rinja/src/filters/escape.rs

@@ -466,16 +466,6 @@ mark_html_safe! {
     std::num::NonZeroU64, std::num::NonZeroU128, std::num::NonZeroUsize,
 }
 
-impl<T: HtmlSafe + ?Sized> HtmlSafe for &T {}
-impl<T: HtmlSafe + ?Sized> HtmlSafe for Box<T> {}
-impl<T: HtmlSafe + ?Sized> HtmlSafe for std::cell::Ref<'_, T> {}
-impl<T: HtmlSafe + ?Sized> HtmlSafe for std::cell::RefMut<'_, T> {}
-impl<T: HtmlSafe + ?Sized> HtmlSafe for std::rc::Rc<T> {}
-impl<T: HtmlSafe + ?Sized> HtmlSafe for std::pin::Pin<&T> {}
-impl<T: HtmlSafe + ?Sized> HtmlSafe for std::sync::Arc<T> {}
-impl<T: HtmlSafe + ?Sized> HtmlSafe for std::sync::MutexGuard<'_, T> {}
-impl<T: HtmlSafe + ?Sized> HtmlSafe for std::sync::RwLockReadGuard<'_, T> {}
-impl<T: HtmlSafe + ?Sized> HtmlSafe for std::sync::RwLockWriteGuard<'_, T> {}
 impl<T: HtmlSafe> HtmlSafe for std::num::Wrapping<T> {}
 impl<T: fmt::Display> HtmlSafe for HtmlSafeOutput<T> {}
 
@@ -486,6 +476,12 @@ where
 {
 }
 
+crate::impl_for_ref! {
+    impl HtmlSafe for T {}
+}
+
+impl<T: HtmlSafe> HtmlSafe for Pin<T> {}
+
 /// Used internally by rinja to select the appropriate [`write!()`] mechanism
 pub struct Writable<'a, S: ?Sized>(pub &'a S);
 

testing/tests/simple.rs

@@ -1,8 +1,13 @@
 #![allow(clippy::disallowed_names)] // For the use of `foo` in test cases
 
+use std::cell::{RefCell, RefMut};
 use std::collections::HashMap;
+use std::fmt;
+use std::pin::Pin;
+use std::sync::{Arc, Mutex, MutexGuard};
 
 use rinja::Template;
+use rinja::filters::HtmlSafe;
 
 #[derive(Template)]
 #[template(path = "simple.html")]
@@ -560,3 +565,31 @@ struct SplitTemplateDeclaration;
 fn test_split_template_declaration() {
     assert_eq!(SplitTemplateDeclaration.to_string(), "🙂");
 }
+
+#[test]
+fn test_ref_custom_type() {
+    const TEXT: &str = "&this <is >not 'safe";
+
+    struct MySafeType;
+
+    impl HtmlSafe for MySafeType {}
+
+    impl fmt::Display for MySafeType {
+        fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+            f.write_str(TEXT)
+        }
+    }
+
+    #[derive(Template)]
+    #[template(ext = "html", source = "{{ data }}")]
+    struct MyTemplate<'a, 'b, 'c> {
+        data: &'a mut RefMut<'b, Pin<Arc<MutexGuard<'c, MySafeType>>>>,
+    }
+
+    let mutex = Mutex::new(MySafeType);
+    let cell = RefCell::new(Arc::pin(mutex.try_lock().unwrap()));
+    let tmpl = MyTemplate {
+        data: &mut cell.try_borrow_mut().unwrap(),
+    };
+    assert_eq!(tmpl.render().unwrap(), TEXT);
+}