Add test

Author: edwin0cheng

crates/ra_hir_expand/src/builtin_derive.rs

@@ -165,7 +165,7 @@ fn find_builtin_crate(db: &dyn AstDatabase, id: LazyMacroId) -> tt::TokenTree {
         crates.iter().filter_map(|krate| cg[*krate].display_name.clone()).map(|it| it.to_string());
 
     let tt = if crate_names.any(|name| name == "std" || name == "core") {
-        quote! { krate }
+        quote! { crate }
     } else {
         quote! { core }
     };

crates/ra_hir_ty/src/tests/macros.rs

@@ -642,6 +642,32 @@ mod clone {
     assert_eq!("S", type_at_pos(&db, pos));
 }
 
+#[test]
+fn infer_derive_clone_in_core() {
+    let (db, pos) = TestDB::with_position(
+        r#"
+//- /main.rs crate:main deps:core
+use core::S;
+fn test() {
+    S.clone()<|>;
+}
+
+//- /lib.rs crate:core
+#[prelude_import]
+use clone::*;
+mod clone {
+    trait Clone {
+        fn clone(&self) -> Self;
+    }
+}
+#[derive(Clone)]
+pub struct S;
+
+"#,
+    );
+    assert_eq!("S", type_at_pos(&db, pos));
+}
+
 #[test]
 fn infer_derive_clone_with_params() {
     let (db, pos) = TestDB::with_position(