fix: show non-std enum in a fresh use tree completion

Author: yue4u

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

@@ -101,11 +101,22 @@ pub(crate) fn complete_use_tree(acc: &mut Completions, ctx: &CompletionContext)
             cov_mark::hit!(use_tree_crate_roots_only);
             acc.add_crate_roots(ctx);
         }
-        // only show modules in a fresh UseTree
+        // only show modules and non-std enum in a fresh UseTree
         None => {
-            cov_mark::hit!(unqualified_path_only_modules_in_import);
+            cov_mark::hit!(unqualified_path_selected_only);
             ctx.process_all_names(&mut |name, res| {
-                if let ScopeDef::ModuleDef(hir::ModuleDef::Module(_)) = res {
+                let should_add_resolution = match res {
+                    ScopeDef::ModuleDef(hir::ModuleDef::Module(_)) => true,
+                    ScopeDef::ModuleDef(hir::ModuleDef::Adt(hir::Adt::Enum(_))) => {
+                        match res.krate(ctx.db) {
+                            // exclude prelude enum
+                            Some(krate) => !krate.is_builtin(ctx.db),
+                            _ => true,
+                        }
+                    }
+                    _ => false,
+                };
+                if should_add_resolution {
                     acc.add_resolution(ctx, name, res);
                 }
             });

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

@@ -10,18 +10,23 @@ fn check(ra_fixture: &str, expect: Expect) {
 
 #[test]
 fn use_tree_start() {
-    cov_mark::check!(unqualified_path_only_modules_in_import);
+    cov_mark::check!(unqualified_path_selected_only);
     check(
         r#"
 //- /lib.rs crate:main deps:other_crate
 use f$0
 
 struct Foo;
+enum FooBar {
+    Foo,
+    Bar
+}
 mod foo {}
 //- /other_crate/lib.rs crate:other_crate
 // nothing here
 "#,
         expect![[r#"
+            en FooBar
             md foo
             md other_crate
             kw crate::