Add doc(alias)-based use and other mod completion

Author: hecatia-elegua

crates/ide-completion/src/completions/expr.rs

@@ -88,7 +88,7 @@ pub(crate) fn complete_expr_path(
                     let module_scope = module.scope(ctx.db, Some(ctx.module));
                     for (name, def) in module_scope {
                         if scope_def_applicable(def) {
-                            acc.add_path_resolution(ctx, path_ctx, name, def, vec![]);
+                            acc.add_path_resolution(ctx, path_ctx, name, def, ctx.doc_aliases_in_scope(def));
                         }
                     }
                 }

crates/ide-completion/src/context.rs

@@ -555,7 +555,7 @@ impl<'a> CompletionContext<'a> {
         self.krate != defining_crate && attrs.has_doc_hidden()
     }
 
-    fn doc_aliases_in_scope(&self, scope_def: ScopeDef) -> Vec<SmolStr> {
+    pub(crate) fn doc_aliases_in_scope(&self, scope_def: ScopeDef) -> Vec<SmolStr> {
         if let Some(attrs) = scope_def.attrs(self.db) {
             attrs.doc_aliases().collect()
         } else {

crates/ide-completion/src/item.rs

@@ -409,7 +409,8 @@ impl Builder {
         local_name: hir::Name,
         resolution: hir::ScopeDef,
     ) -> Self {
-        render_path_resolution(RenderContext::new(ctx), path_ctx, local_name, resolution)
+        let doc_aliases = ctx.doc_aliases_in_scope(resolution);
+        render_path_resolution(RenderContext::new(ctx).doc_aliases(doc_aliases), path_ctx, local_name, resolution)
     }
 
     pub(crate) fn build(self) -> CompletionItem {

crates/ide-completion/src/tests/special.rs

@@ -1150,3 +1150,42 @@ fn bar() { qu$0 }
         "#]],
     );
 }
+
+#[test]
+fn completes_struct_name_via_doc_alias_in_another_mod() {
+    check(
+        r#"
+mod foo {
+    #[doc(alias = "Qux")]
+    pub struct Bar(u8);
+}
+
+fn here_we_go() {
+    use foo;
+    let foo = foo::Q$0
+}
+"#,
+        expect![[r#"
+            st Bar (alias Qux)
+        "#]],
+    );
+}
+
+#[test]
+fn completes_use_via_doc_alias_in_another_mod() {
+    check(
+        r#"
+mod foo {
+    #[doc(alias = "Qux")]
+    pub struct Bar(u8);
+}
+
+fn here_we_go() {
+    use foo::Q$0;
+}
+"#,
+        expect![[r#"
+            st Bar (alias Qux)
+        "#]],
+    );
+}