Fixes parsing for config attrs in pallet macros (#2677)

substrate/frame/support/test/tests/derive_impl.rs

@@ -0,0 +1,52 @@
+// This file is part of Substrate.
+
+// Copyright (C) Parity Technologies (UK) Ltd.
+// SPDX-License-Identifier: Apache-2.0
+
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// 	http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+use frame_support::derive_impl;
+
+trait Shape {
+	fn area(&self) -> u32;
+}
+
+struct SomeRectangle {}
+
+#[frame_support::register_default_impl(SomeRectangle)]
+impl Shape for SomeRectangle {
+	#[cfg(not(feature = "feature-frame-testing"))]
+	fn area(&self) -> u32 {
+		10
+	}
+
+	#[cfg(feature = "feature-frame-testing")]
+	fn area(&self) -> u32 {
+		0
+	}
+}
+
+struct SomeSquare {}
+
+#[derive_impl(SomeRectangle)]
+impl Shape for SomeSquare {}
+
+#[test]
+fn test_feature_parsing() {
+	let square = SomeSquare {};
+	#[cfg(not(feature = "feature-frame-testing"))]
+	assert_eq!(square.area(), 10);
+
+	#[cfg(feature = "feature-frame-testing")]
+	assert_eq!(square.area(), 0);
+}