fix: auto-complete import for aliased function and module

Author: dqkqd

src/tools/rust-analyzer/crates/ide-completion/src/render.rs

@@ -281,8 +281,14 @@ pub(crate) fn render_resolution_with_import(
     import_edit: LocatedImport,
 ) -> Option<Builder> {
     let resolution = ScopeDef::from(import_edit.original_item);
-    let local_name = scope_def_to_name(resolution, &ctx, &import_edit)?;
-    //this now just renders the alias text, but we need to find the aliases earlier and call this with the alias instead
+    // Use the last segment when `item_to_import` matches `original_item`,
+    // as it will take the aliased name into account.
+    let local_name = if import_edit.item_to_import == import_edit.original_item {
+        import_edit.import_path.segments().last()?.clone()
+    } else {
+        scope_def_to_name(resolution, &ctx, &import_edit)?
+    };
+    // This now just renders the alias text, but we need to find the aliases earlier and call this with the alias instead.
     let doc_aliases = ctx.completion.doc_aliases_in_scope(resolution);
     let ctx = ctx.doc_aliases(doc_aliases);
     Some(render_resolution_path(ctx, path_ctx, local_name, Some(import_edit), resolution))

src/tools/rust-analyzer/crates/ide-completion/src/tests/flyimport.rs

@@ -1669,3 +1669,45 @@ mod module {
         "#]],
     );
 }
+
+#[test]
+fn re_export_aliased_function() {
+    check(
+        r#"
+//- /lib.rs crate:bar
+pub fn func(_: i32) -> i32 {}
+
+//- /lib.rs crate:foo deps:bar
+pub use bar::func as my_func;
+
+//- /main.rs crate:main deps:foo
+fn main() {
+    m$0
+}
+"#,
+        expect![[r#"
+            fn my_func(…) (use foo::my_func) fn(i32) -> i32
+        "#]],
+    );
+}
+
+#[test]
+fn re_export_aliased_module() {
+    check(
+        r#"
+//- /lib.rs crate:bar
+pub mod baz {}
+
+//- /lib.rs crate:foo deps:bar
+pub use bar::baz as my_baz;
+
+//- /main.rs crate:main deps:foo
+fn main() {
+    m$0
+}
+"#,
+        expect![[r#"
+            md my_baz (use foo::my_baz)
+        "#]],
+    );
+}