return error for unused #[convert]s

2 files changed, 12 insertions, 0 deletions

diff --git a/ui-tests/src/bin/attr_convert_unused.rs b/ui-tests/src/bin/attr_convert_unused.rs
new file mode 100644
index 0000000..b7ee474
--- /dev/null
+++ b/ui-tests/src/bin/attr_convert_unused.rs
@@ -0,0 +1,7 @@
+#[dynamize::dynamize]
+#[convert = |x: Foo| -> Bar {x.baz()}]
+trait Trait {
+    fn test(&self);
+}
+
+fn main() {}
diff --git a/ui-tests/src/bin/attr_convert_unused.stderr b/ui-tests/src/bin/attr_convert_unused.stderr
new file mode 100644
index 0000000..e715236
--- /dev/null
+++ b/ui-tests/src/bin/attr_convert_unused.stderr
@@ -0,0 +1,5 @@
+error: unused conversion
+ --> src/bin/attr_convert_unused.rs:2:17
+  |
+2 | #[convert = |x: Foo| -> Bar {x.baz()}]
+  |                 ^^^