From a88344152d831c9b7c51fe23a098764b5aa8451e Mon Sep 17 00:00:00 2001
From: Aleksey Kladov <aleksey.kladov@gmail.com>
Date: Sun, 10 Oct 2021 16:13:45 +0300
Subject: [PATCH] minor: add a test for derive macros in core

---
 .../builtin_derive_macro.rs                   | 20 +++++++++++++++++++
 crates/hir_expand/src/builtin_derive_macro.rs |  1 +
 2 files changed, 21 insertions(+)

diff --git a/crates/hir_def/src/macro_expansion_tests/builtin_derive_macro.rs b/crates/hir_def/src/macro_expansion_tests/builtin_derive_macro.rs
index 177409dc380..aa50fa6d33e 100644
--- a/crates/hir_def/src/macro_expansion_tests/builtin_derive_macro.rs
+++ b/crates/hir_def/src/macro_expansion_tests/builtin_derive_macro.rs
@@ -20,6 +20,26 @@ impl < > core::marker::Copy for Foo< > {}"##]],
     );
 }
 
+#[test]
+fn test_copy_expand_in_core() {
+    cov_mark::check!(test_copy_expand_in_core);
+    check(
+        r#"
+#[rustc_builtin_macro]
+macro Copy {}
+#[derive(Copy)]
+struct Foo;
+"#,
+        expect![[r##"
+#[rustc_builtin_macro]
+macro Copy {}
+#[derive(Copy)]
+struct Foo;
+
+impl < > crate ::marker::Copy for Foo< > {}"##]],
+    );
+}
+
 #[test]
 fn test_copy_expand_with_type_params() {
     check(
diff --git a/crates/hir_expand/src/builtin_derive_macro.rs b/crates/hir_expand/src/builtin_derive_macro.rs
index d4fcf42dd3f..31b99e3c411 100644
--- a/crates/hir_expand/src/builtin_derive_macro.rs
+++ b/crates/hir_expand/src/builtin_derive_macro.rs
@@ -176,6 +176,7 @@ fn find_builtin_crate(db: &dyn AstDatabase, id: MacroCallId) -> tt::TokenTree {
     let tt = if cg[krate].dependencies.iter().any(|dep| &*dep.name == "core") {
         quote! { core }
     } else {
+        cov_mark::hit!(test_copy_expand_in_core);
         quote! { crate }
     };