Test that primary flag is properly set on default validator

Closes gh-1243

Author: snicoll

samples/validator/src/test/java/com/example/validator/ValidatorApplicationTests.java

@@ -1,14 +1,50 @@
+/*
+ * Copyright 2019-2021 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 com.example.validator;
 
 import org.junit.jupiter.api.Test;
 
+import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.boot.test.context.SpringBootTest;
+import org.springframework.context.support.GenericApplicationContext;
+import org.springframework.validation.Validator;
+
+import static org.assertj.core.api.Assertions.assertThat;
 
 @SpringBootTest
-public class ValidatorApplicationTests {
+class ValidatorApplicationTests {
+
+	@Autowired(required = false)
+	private Validator validator;
+
+	@Autowired
+	private GenericApplicationContext applicationContext;
+
+	@Test
+	void validatorHasPrimaryFlag() {
+		assertThat(this.validator).isNotNull();
+		assertThat(this.applicationContext.containsBeanDefinition("defaultValidator")).isTrue();
+		assertThat(this.applicationContext.getBeanDefinition("defaultValidator").isPrimary()).isTrue();
+	}
 
 	@Test
-	public void contextLoads() {
+	void twoValidatorsAreDefined() {
+		assertThat(this.applicationContext.getBeansOfType(Validator.class))
+				.containsOnlyKeys("defaultValidator", "mvcValidator");
 	}
 
 }