Use @AliasFor in @AutoConfigureRestDocs

Replace custom alias logic in @AutoConfigureRestDocs with @AliasFor.

Closes gh-6403

spring-boot-test-autoconfigure/src/main/java/org/springframework/boot/test/autoconfigure/restdocs/AutoConfigureRestDocs.java

@@ -25,6 +25,7 @@ import java.lang.annotation.Target;
 import org.springframework.boot.autoconfigure.ImportAutoConfiguration;
 import org.springframework.boot.test.autoconfigure.properties.PropertyMapping;
 import org.springframework.context.annotation.Import;
+import org.springframework.core.annotation.AliasFor;
 
 /**
  * Annotation that can be applied to a test class to enable and configure
@@ -46,17 +47,19 @@ import org.springframework.context.annotation.Import;
 public @interface AutoConfigureRestDocs {
 
 	/**
-	 * The output directory to which generated snippets will be written. A synonym for
+	 * The output directory to which generated snippets will be written. A alias for
 	 * {@link #outputDir}.
 	 * @return the output directory
 	 */
+	@AliasFor("outputDir")
 	String value() default "";
 
 	/**
-	 * The output directory to which generated snippets will be written. A synonym for
+	 * The output directory to which generated snippets will be written. A alias for
 	 * {@link #value}.
 	 * @return the output directory
 	 */
+	@AliasFor("value")
 	String outputDir() default "";
 
 	/**

spring-boot-test-autoconfigure/src/main/java/org/springframework/boot/test/autoconfigure/restdocs/RestDocumentationContextProviderRegistrar.java

@@ -24,38 +24,26 @@ import org.springframework.beans.factory.support.BeanDefinitionRegistry;
 import org.springframework.context.annotation.ImportBeanDefinitionRegistrar;
 import org.springframework.core.type.AnnotationMetadata;
 import org.springframework.restdocs.ManualRestDocumentation;
-import org.springframework.util.StringUtils;
 
 /**
  * {@link ImportBeanDefinitionRegistrar} used by {@link AutoConfigureRestDocs}.
  *
  * @author Andy Wilkinson
+ * @see AutoConfigureRestDocs
  */
 class RestDocumentationContextProviderRegistrar implements ImportBeanDefinitionRegistrar {
 
 	@Override
 	public void registerBeanDefinitions(AnnotationMetadata importingClassMetadata,
 			BeanDefinitionRegistry registry) {
+		Map<String, Object> annotationAttributes = importingClassMetadata
+				.getAnnotationAttributes(AutoConfigureRestDocs.class.getName());
+		String outputDir = (String) annotationAttributes.get("outputDir");
 		AbstractBeanDefinition beanDefinition = BeanDefinitionBuilder
 				.genericBeanDefinition(ManualRestDocumentation.class)
-				.addConstructorArgValue(determineOutputDir(importingClassMetadata))
+				.addConstructorArgValue(outputDir).getBeanDefinition();
-				.getBeanDefinition();
 		registry.registerBeanDefinition(ManualRestDocumentation.class.getName(),
 				beanDefinition);
 	}
 
-	private String determineOutputDir(AnnotationMetadata annotationMetadata) {
-		Map<String, Object> annotationAttributes = annotationMetadata
-				.getAnnotationAttributes(AutoConfigureRestDocs.class.getName());
-		String outputDir = (String) annotationAttributes.get("outputDir");
-		if (!StringUtils.hasText(outputDir)) {
-			outputDir = (String) annotationAttributes.get("value");
-			if (!StringUtils.hasText(outputDir)) {
-				throw new IllegalStateException(
-						"Either value or outputDir must be specified on @AutoConfigureRestDocs");
-			}
-		}
-		return outputDir;
-	}
-
 }

spring-boot-test-autoconfigure/src/test/java/org/springframework/boot/test/autoconfigure/restdocs/RestDocsAutoConfigurationAdvancedConfigurationIntegrationTests.java

@@ -47,7 +47,7 @@ import static org.springframework.test.web.servlet.request.MockMvcRequestBuilder
  */
 @RunWith(SpringRunner.class)
 @WebMvcTest(controllers = RestDocsTestController.class, secure = false)
-@AutoConfigureRestDocs(outputDir = "target/generated-snippets")
+@AutoConfigureRestDocs("target/generated-snippets")
 public class RestDocsAutoConfigurationAdvancedConfigurationIntegrationTests {
 
 	@Before