Fix importing private modules in expand glob import

Author: unexge

crates/assists/src/handlers/expand_glob_import.rs

@@ -162,11 +162,28 @@ fn find_refs_in_mod(
     module: Module,
     visible_from: Option<Module>,
 ) -> Option<Refs> {
+    if let Some(from) = visible_from {
+        if !is_mod_visible_from(ctx, module, from) {
+            return None;
+        }
+    }
+
     let module_scope = module.scope(ctx.db(), visible_from);
     let refs = module_scope.into_iter().filter_map(|(n, d)| Ref::from_scope_def(n, d)).collect();
     Some(Refs(refs))
 }
 
+fn is_mod_visible_from(ctx: &AssistContext, module: Module, from: Module) -> bool {
+    match module.parent(ctx.db()) {
+        Some(parent) => {
+            parent.visibility_of(ctx.db(), &ModuleDef::Module(module)).map_or(true, |vis| {
+                vis.is_visible_from(ctx.db(), from.into()) && is_mod_visible_from(ctx, parent, from)
+            })
+        }
+        None => true,
+    }
+}
+
 // looks for name refs in parent use block's siblings
 //
 // mod bar {
@@ -815,6 +832,41 @@ fn main() {
         );
     }
 
+    #[test]
+    fn expanding_is_not_applicable_if_target_module_is_not_accessible_from_current_scope() {
+        check_assist_not_applicable(
+            expand_glob_import,
+            r"
+mod foo {
+    mod bar {
+        pub struct Bar;
+    }
+}
+
+use foo::bar::*<|>;
+
+fn baz(bar: Bar) {}
+",
+        );
+
+        check_assist_not_applicable(
+            expand_glob_import,
+            r"
+mod foo {
+    mod bar {
+        pub mod baz {
+            pub struct Baz;
+        }
+    }
+}
+
+use foo::bar::baz::*<|>;
+
+fn qux(baz: Baz) {}
+",
+        );
+    }
+
     #[test]
     fn expanding_is_not_applicable_if_cursor_is_not_in_star_token() {
         check_assist_not_applicable(