Restore proxying of @Bean methods in @TestConfiguration

See gh-18675

spring-boot-project/spring-boot-test/src/test/java/org/springframework/boot/test/context/TestConfigurationTests.java

@@ -0,0 +1,55 @@
+/*
+ * Copyright 2012-2019 the original author or authors.
+ *
+ * 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
+ *
+ *      https://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.
+ */
+
+package org.springframework.boot.test.context;
+
+import org.assertj.core.api.Assertions;
+import org.junit.jupiter.api.Test;
+
+import org.springframework.boot.test.context.runner.ApplicationContextRunner;
+
+/**
+ * Tests for {@link TestConfiguration}.
+ *
+ * @author Dmytro Nosan
+ */
+class TestConfigurationTests {
+
+	private final ApplicationContextRunner contextRunner = new ApplicationContextRunner();
+
+	@Test
+	void shouldProxyBeanMethods() {
+		this.contextRunner.withUserConfiguration(ProxyBeanMethodsConfiguration.class)
+				.run((context) -> Assertions.assertThat(context).hasFailed());
+	}
+
+	@Test
+	void shouldNotProxyBeanMethods() {
+		this.contextRunner.withUserConfiguration(ProxyBeanMethodsDisableConfiguration.class)
+				.run((context) -> Assertions.assertThat(context).hasNotFailed());
+	}
+
+	@TestConfiguration
+	final static class ProxyBeanMethodsConfiguration {
+
+	}
+
+	@TestConfiguration(proxyBeanMethods = false)
+	final static class ProxyBeanMethodsDisableConfiguration {
+
+	}
+
+}