Merge pull request #20255 from A4-Tacks/deref-intranstive

Fix ide-assist: generate Deref transitive

Author: lnicola

src/tools/rust-analyzer/crates/ide-assists/src/handlers/generate_deref.rs

@@ -10,7 +10,7 @@ use syntax::{
 use crate::{
     AssistId,
     assist_context::{AssistContext, Assists, SourceChangeBuilder},
-    utils::generate_trait_impl_text,
+    utils::generate_trait_impl_text_intransitive,
 };
 
 // Assist: generate_deref
@@ -150,7 +150,7 @@ fn generate_edit(
         ),
     };
     let strukt_adt = ast::Adt::Struct(strukt);
-    let deref_impl = generate_trait_impl_text(
+    let deref_impl = generate_trait_impl_text_intransitive(
         &strukt_adt,
         &trait_path.display(db, edition).to_string(),
         &impl_code,
@@ -227,6 +227,28 @@ impl core::ops::Deref for B {
         );
     }
 
+    #[test]
+    fn test_generate_record_deref_with_generic() {
+        check_assist(
+            generate_deref,
+            r#"
+//- minicore: deref
+struct A<T>($0T);
+"#,
+            r#"
+struct A<T>(T);
+
+impl<T> core::ops::Deref for A<T> {
+    type Target = T;
+
+    fn deref(&self) -> &Self::Target {
+        &self.0
+    }
+}
+"#,
+        );
+    }
+
     #[test]
     fn test_generate_record_deref_short_path() {
         check_assist(

src/tools/rust-analyzer/crates/ide-assists/src/utils.rs

@@ -567,6 +567,7 @@ pub(crate) fn generate_impl_text(adt: &ast::Adt, code: &str) -> String {
 ///
 /// This is useful for traits like `PartialEq`, since `impl<T> PartialEq for U<T>` often requires `T: PartialEq`.
 // FIXME: migrate remaining uses to `generate_trait_impl`
+#[allow(dead_code)]
 pub(crate) fn generate_trait_impl_text(adt: &ast::Adt, trait_text: &str, code: &str) -> String {
     generate_impl_text_inner(adt, Some(trait_text), true, code)
 }