Goto definition works for `S { a: }` case

What happens here is that we lower `: ` to a missing expression, and
then correctly record that the corresponding field expression resolves
to a specific field. Where we fail is in the mapping of syntax to this
missing expression. Doing it via `ast_field.expr()` fails, as that
expression is `None`. Instead, we go in the opposite direcition and ask
each lowered field about its source.

This works, but has wrong complexity `O(N)` and, really, the
implementation is just too complex. We need some better management of
data here.

1 files changed, 11 insertions, 0 deletions

diff --git a/crates/ide/src/goto_definition.rs b/crates/ide/src/goto_definition.rs
index abed1969e..e8f31e4b1 100644
--- a/crates/ide/src/goto_definition.rs
+++ b/crates/ide/src/goto_definition.rs
@@ -1161,4 +1161,15 @@ struct S;
 "#,
         )
     }
+
+    #[test]
+    fn goto_incomplete_field() {
+        check(
+            r#"
+struct A { a: u32 }
+         //^
+fn foo() { A { a$0: }; }
+"#,
+        )
+    }
 }