Merge #3692

3692: Introduce `MacroDefKind::CustomDerive` r=matklad a=edwin0cheng

This PR introduce a new `MacroDefKind` `CustomDerive`. And use a new `ProcMacroExpander` for its expanding. And the expander is a dummy for now. 

Related: #3654 

Co-authored-by: Edwin Cheng <[email protected]>

1 files changed, 19 insertions, 0 deletions

diff --git a/crates/ra_hir_ty/src/tests/macros.rs b/crates/ra_hir_ty/src/tests/macros.rs
index 2e309a379..eb97288f1 100644
--- a/crates/ra_hir_ty/src/tests/macros.rs
+++ b/crates/ra_hir_ty/src/tests/macros.rs
@@ -639,3 +639,22 @@ mod clone {
     );
     assert_eq!("(Wrapper<S>, {unknown})", type_at_pos(&db, pos));
 }
+
+#[test]
+fn infer_custom_derive_simple() {
+    // FIXME: this test current now do nothing
+    let (db, pos) = TestDB::with_position(
+        r#"
+//- /main.rs crate:main
+use foo::Foo;
+
+#[derive(Foo)]
+struct S{}
+
+fn test() {
+    S{}<|>;
+}
+"#,
+    );
+    assert_eq!("S", type_at_pos(&db, pos));
+}