Reject use of component scan with REGISTER_BEAN condition

This commit introduce a change of behaviour when component scan is used
with conditions. Previously, any condition in the REGISTER_BEAN phase
were ignored and the scan was applied regardless of the outcome of
those conditions. This is because REGISTER_BEAN condition evaluation
happens later in the bean factory preparation.

Rather than ignoring those conditions, this commit fails fast when it
detects such use case. Code will have to be adapted accordingly.

Closes gh-23206

spring-context/src/test/java/org/springframework/context/annotation/Gh23206Tests.java

@@ -0,0 +1,89 @@
+/*
+ * Copyright 2002-2024 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.context.annotation;
+
+import org.junit.jupiter.api.Test;
+
+import org.springframework.beans.factory.BeanDefinitionStoreException;
+import org.springframework.context.ApplicationContextException;
+import org.springframework.context.annotation.componentscan.simple.SimpleComponent;
+import org.springframework.core.type.AnnotatedTypeMetadata;
+
+import static org.assertj.core.api.Assertions.assertThatExceptionOfType;
+
+/**
+ * Tests for gh-23206.
+ *
+ * @author Stephane Nicoll
+ */
+public class Gh23206Tests {
+
+	@Test
+	void componentScanShouldFailWithRegisterBeanCondition() {
+		AnnotationConfigApplicationContext context = new AnnotationConfigApplicationContext();
+		context.register(ConditionalComponentScanConfiguration.class);
+		assertThatExceptionOfType(BeanDefinitionStoreException.class).isThrownBy(context::refresh)
+				.withMessageContaining(ConditionalComponentScanConfiguration.class.getName())
+				.havingCause().isInstanceOf(ApplicationContextException.class)
+				.withMessageContaining("Component scan could not be used with conditions in REGISTER_BEAN phase");
+	}
+
+	@Test
+	void componentScanShouldFailWithRegisterBeanConditionOnClasThatImportedIt() {
+		AnnotationConfigApplicationContext context = new AnnotationConfigApplicationContext();
+		context.register(ConditionalConfiguration.class);
+		assertThatExceptionOfType(BeanDefinitionStoreException.class).isThrownBy(context::refresh)
+				.withMessageContaining(ConditionalConfiguration.class.getName())
+				.havingCause().isInstanceOf(ApplicationContextException.class)
+				.withMessageContaining("Component scan could not be used with conditions in REGISTER_BEAN phase");
+	}
+
+
+	@Configuration(proxyBeanMethods = false)
+	@Conditional(NeverRegisterBeanCondition.class)
+	@ComponentScan(basePackageClasses = SimpleComponent.class)
+	static class ConditionalComponentScanConfiguration {
+
+	}
+
+
+	@Configuration(proxyBeanMethods = false)
+	@Conditional(NeverRegisterBeanCondition.class)
+	static class ConditionalConfiguration {
+
+		@Configuration(proxyBeanMethods = false)
+		@ComponentScan(basePackageClasses = SimpleComponent.class)
+		static class NestedConfiguration {
+		}
+
+	}
+
+
+	static class NeverRegisterBeanCondition implements ConfigurationCondition {
+
+		@Override
+		public boolean matches(ConditionContext context, AnnotatedTypeMetadata metadata) {
+			return false;
+		}
+
+		@Override
+		public ConfigurationPhase getConfigurationPhase() {
+			return ConfigurationPhase.REGISTER_BEAN;
+		}
+
+	}
+}