Revise RepeatableContainersTests

spring-core/src/test/java/org/springframework/core/annotation/RepeatableContainersTests.java

@@ -20,7 +20,9 @@ import java.lang.annotation.Annotation;
 import java.lang.annotation.Repeatable;
 import java.lang.annotation.Retention;
 import java.lang.annotation.RetentionPolicy;
+import java.util.Arrays;
 
+import org.junit.jupiter.api.Nested;
 import org.junit.jupiter.api.Test;
 
 import static org.assertj.core.api.Assertions.assertThat;
@@ -31,189 +33,162 @@ import static org.assertj.core.api.Assertions.assertThatIllegalArgumentException
  * Tests for {@link RepeatableContainers}.
  *
  * @author Phillip Webb
+ * @author Sam Brannen
  */
 class RepeatableContainersTests {
 
-	@Test
-	void standardRepeatablesWhenNonRepeatableReturnsNull() {
-		Object[] values = findRepeatedAnnotationValues(
-				RepeatableContainers.standardRepeatables(), WithNonRepeatable.class,
-				NonRepeatable.class);
-		assertThat(values).isNull();
-	}
+	@Nested
+	class StandardRepeatableContainersTests {
 
-	@Test
-	void standardRepeatablesWhenSingleReturnsNull() {
-		Object[] values = findRepeatedAnnotationValues(
-				RepeatableContainers.standardRepeatables(),
-				WithSingleStandardRepeatable.class, StandardRepeatable.class);
-		assertThat(values).isNull();
-	}
+		@Test
+		void standardRepeatablesWhenNonRepeatableReturnsNull() {
+			Object[] values = findRepeatedAnnotationValues(RepeatableContainers.standardRepeatables(),
+				NonRepeatableTestCase.class, NonRepeatable.class);
+			assertThat(values).isNull();
+		}
 
-	@Test
-	void standardRepeatablesWhenContainerReturnsRepeats() {
-		Object[] values = findRepeatedAnnotationValues(
-				RepeatableContainers.standardRepeatables(), WithStandardRepeatables.class,
-				StandardContainer.class);
-		assertThat(values).containsExactly("a", "b");
-	}
+		@Test
+		void standardRepeatablesWhenSingleReturnsNull() {
+			Object[] values = findRepeatedAnnotationValues(RepeatableContainers.standardRepeatables(),
+				SingleStandardRepeatableTestCase.class, StandardRepeatable.class);
+			assertThat(values).isNull();
+		}
 
-	@Test
-	void standardRepeatablesWhenContainerButNotRepeatableReturnsNull() {
-		Object[] values = findRepeatedAnnotationValues(
-				RepeatableContainers.standardRepeatables(), WithExplicitRepeatables.class,
-				ExplicitContainer.class);
-		assertThat(values).isNull();
-	}
+		@Test
+		void standardRepeatablesWhenContainerButNotRepeatableReturnsNull() {
+			Object[] values = findRepeatedAnnotationValues(RepeatableContainers.standardRepeatables(),
+				ExplicitRepeatablesTestCase.class, ExplicitContainer.class);
+			assertThat(values).isNull();
+		}
 
-	@Test
-	void ofExplicitWhenNonRepeatableReturnsNull() {
-		Object[] values = findRepeatedAnnotationValues(
-				RepeatableContainers.of(ExplicitRepeatable.class,
-						ExplicitContainer.class),
-				WithNonRepeatable.class, NonRepeatable.class);
-		assertThat(values).isNull();
+		@Test
+		void standardRepeatablesWhenContainerReturnsRepeats() {
+			Object[] values = findRepeatedAnnotationValues(RepeatableContainers.standardRepeatables(),
+				StandardRepeatablesTestCase.class, StandardContainer.class);
+			assertThat(values).containsExactly("a", "b");
+		}
 	}
 
-	@Test
-	void ofExplicitWhenStandardRepeatableContainerReturnsNull() {
-		Object[] values = findRepeatedAnnotationValues(
-				RepeatableContainers.of(ExplicitRepeatable.class,
-						ExplicitContainer.class),
-				WithStandardRepeatables.class, StandardContainer.class);
-		assertThat(values).isNull();
-	}
+	@Nested
+	class ExplicitRepeatableContainerTests {
 
-	@Test
-	void ofExplicitWhenContainerReturnsRepeats() {
-		Object[] values = findRepeatedAnnotationValues(
-				RepeatableContainers.of(ExplicitRepeatable.class,
-						ExplicitContainer.class),
-				WithExplicitRepeatables.class, ExplicitContainer.class);
-		assertThat(values).containsExactly("a", "b");
-	}
+		@Test
+		void ofExplicitWhenNonRepeatableReturnsNull() {
+			Object[] values = findRepeatedAnnotationValues(
+				RepeatableContainers.of(ExplicitRepeatable.class, ExplicitContainer.class),
+				NonRepeatableTestCase.class, NonRepeatable.class);
+			assertThat(values).isNull();
+		}
 
-	@Test
-	void ofExplicitWhenHasNoValueThrowsException() {
-		assertThatExceptionOfType(AnnotationConfigurationException.class).isThrownBy(() ->
-				RepeatableContainers.of(ExplicitRepeatable.class, InvalidNoValue.class))
-			.withMessageContaining("Invalid declaration of container type ["
-									+ InvalidNoValue.class.getName()
-									+ "] for repeatable annotation ["
-									+ ExplicitRepeatable.class.getName() + "]");
-	}
+		@Test
+		void ofExplicitWhenStandardRepeatableContainerReturnsNull() {
+			Object[] values = findRepeatedAnnotationValues(
+				RepeatableContainers.of(ExplicitRepeatable.class, ExplicitContainer.class),
+				StandardRepeatablesTestCase.class, StandardContainer.class);
+			assertThat(values).isNull();
+		}
 
-	@Test
-	void ofExplicitWhenValueIsNotArrayThrowsException() {
-		assertThatExceptionOfType(AnnotationConfigurationException.class).isThrownBy(() ->
-				RepeatableContainers.of(ExplicitRepeatable.class, InvalidNotArray.class))
-			.withMessage("Container type ["
-								+ InvalidNotArray.class.getName()
-								+ "] must declare a 'value' attribute for an array of type ["
-								+ ExplicitRepeatable.class.getName() + "]");
-	}
+		@Test
+		void ofExplicitWhenContainerReturnsRepeats() {
+			Object[] values = findRepeatedAnnotationValues(
+				RepeatableContainers.of(ExplicitRepeatable.class, ExplicitContainer.class),
+				ExplicitRepeatablesTestCase.class, ExplicitContainer.class);
+			assertThat(values).containsExactly("a", "b");
+		}
 
-	@Test
-	void ofExplicitWhenValueIsArrayOfWrongTypeThrowsException() {
-		assertThatExceptionOfType(AnnotationConfigurationException.class).isThrownBy(() ->
-				RepeatableContainers.of(ExplicitRepeatable.class, InvalidWrongArrayType.class))
-			.withMessage("Container type ["
-								+ InvalidWrongArrayType.class.getName()
-								+ "] must declare a 'value' attribute for an array of type ["
-								+ ExplicitRepeatable.class.getName() + "]");
-	}
+		@Test
+		void ofExplicitWhenContainerIsNullDeducesContainer() {
+			Object[] values = findRepeatedAnnotationValues(RepeatableContainers.of(StandardRepeatable.class, null),
+				StandardRepeatablesTestCase.class, StandardContainer.class);
+			assertThat(values).containsExactly("a", "b");
+		}
 
-	@Test
-	void ofExplicitWhenAnnotationIsNullThrowsException() {
-		assertThatIllegalArgumentException().isThrownBy(() ->
-				RepeatableContainers.of(null, null))
-			.withMessage("Repeatable must not be null");
-	}
+		@Test
+		void ofExplicitWhenHasNoValueThrowsException() {
+			assertThatExceptionOfType(AnnotationConfigurationException.class)
+				.isThrownBy(() -> RepeatableContainers.of(ExplicitRepeatable.class, InvalidNoValue.class))
+				.withMessageContaining("Invalid declaration of container type [%s] for repeatable annotation [%s]",
+					InvalidNoValue.class.getName(), ExplicitRepeatable.class.getName());
+		}
 
-	@Test
-	void ofExplicitWhenContainerIsNullDeducesContainer() {
-		Object[] values = findRepeatedAnnotationValues(
-				RepeatableContainers.of(StandardRepeatable.class, null),
-				WithStandardRepeatables.class, StandardContainer.class);
-		assertThat(values).containsExactly("a", "b");
-	}
+		@Test
+		void ofExplicitWhenValueIsNotArrayThrowsException() {
+			assertThatExceptionOfType(AnnotationConfigurationException.class)
+				.isThrownBy(() -> RepeatableContainers.of(ExplicitRepeatable.class, InvalidNotArray.class))
+				.withMessage("Container type [%s] must declare a 'value' attribute for an array of type [%s]",
+					InvalidNotArray.class.getName(), ExplicitRepeatable.class.getName());
+		}
+
+		@Test
+		void ofExplicitWhenValueIsArrayOfWrongTypeThrowsException() {
+			assertThatExceptionOfType(AnnotationConfigurationException.class)
+				.isThrownBy(() -> RepeatableContainers.of(ExplicitRepeatable.class, InvalidWrongArrayType.class))
+				.withMessage("Container type [%s] must declare a 'value' attribute for an array of type [%s]",
+					InvalidWrongArrayType.class.getName(), ExplicitRepeatable.class.getName());
+		}
+
+		@Test
+		void ofExplicitWhenAnnotationIsNullThrowsException() {
+			assertThatIllegalArgumentException()
+				.isThrownBy(() -> RepeatableContainers.of(null, null))
+				.withMessage("Repeatable must not be null");
+		}
+
+		@Test
+		void ofExplicitWhenContainerIsNullAndNotRepeatableThrowsException() {
+			assertThatIllegalArgumentException()
+				.isThrownBy(() -> RepeatableContainers.of(ExplicitRepeatable.class, null))
+				.withMessage("Annotation type must be a repeatable annotation: failed to resolve container type for %s",
+					ExplicitRepeatable.class.getName());
+		}
 
-	@Test
-	void ofExplicitWhenContainerIsNullAndNotRepeatableThrowsException() {
-		assertThatIllegalArgumentException().isThrownBy(() ->
-				RepeatableContainers.of(ExplicitRepeatable.class, null))
-			.withMessage("Annotation type must be a repeatable annotation: " +
-						"failed to resolve container type for " +
-						ExplicitRepeatable.class.getName());
 	}
 
 	@Test
 	void standardAndExplicitReturnsRepeats() {
-		RepeatableContainers repeatableContainers = RepeatableContainers.standardRepeatables().and(
-				ExplicitContainer.class, ExplicitRepeatable.class);
-		assertThat(findRepeatedAnnotationValues(repeatableContainers,
-				WithStandardRepeatables.class, StandardContainer.class)).containsExactly(
-						"a", "b");
-		assertThat(findRepeatedAnnotationValues(repeatableContainers,
-				WithExplicitRepeatables.class, ExplicitContainer.class)).containsExactly(
-						"a", "b");
+		RepeatableContainers repeatableContainers = RepeatableContainers.standardRepeatables()
+			.and(ExplicitContainer.class, ExplicitRepeatable.class);
+		assertThat(findRepeatedAnnotationValues(repeatableContainers, StandardRepeatablesTestCase.class, StandardContainer.class))
+			.containsExactly("a", "b");
+		assertThat(findRepeatedAnnotationValues(repeatableContainers, ExplicitRepeatablesTestCase.class, ExplicitContainer.class))
+			.containsExactly("a", "b");
 	}
 
 	@Test
 	void noneAlwaysReturnsNull() {
-		Object[] values = findRepeatedAnnotationValues(
-				RepeatableContainers.none(), WithStandardRepeatables.class,
-				StandardContainer.class);
+		Object[] values = findRepeatedAnnotationValues(RepeatableContainers.none(), StandardRepeatablesTestCase.class,
+			StandardContainer.class);
 		assertThat(values).isNull();
 	}
 
 	@Test
 	void equalsAndHashcode() {
-		RepeatableContainers c1 = RepeatableContainers.of(ExplicitRepeatable.class,
-				ExplicitContainer.class);
-		RepeatableContainers c2 = RepeatableContainers.of(ExplicitRepeatable.class,
-				ExplicitContainer.class);
+		RepeatableContainers c1 = RepeatableContainers.of(ExplicitRepeatable.class, ExplicitContainer.class);
+		RepeatableContainers c2 = RepeatableContainers.of(ExplicitRepeatable.class, ExplicitContainer.class);
 		RepeatableContainers c3 = RepeatableContainers.standardRepeatables();
-		RepeatableContainers c4 = RepeatableContainers.standardRepeatables().and(
-				ExplicitContainer.class, ExplicitRepeatable.class);
-		assertThat(c1.hashCode()).isEqualTo(c2.hashCode());
+		RepeatableContainers c4 = RepeatableContainers.standardRepeatables().and(ExplicitContainer.class, ExplicitRepeatable.class);
+		assertThat(c1).hasSameHashCodeAs(c2);
 		assertThat(c1).isEqualTo(c1).isEqualTo(c2);
 		assertThat(c1).isNotEqualTo(c3).isNotEqualTo(c4);
 	}
 
-	private Object[] findRepeatedAnnotationValues(RepeatableContainers containers,
+
+	private static Object[] findRepeatedAnnotationValues(RepeatableContainers containers,
 			Class<?> element, Class<? extends Annotation> annotationType) {
-		Annotation[] annotations = containers.findRepeatedAnnotations(
-				element.getAnnotation(annotationType));
+		Annotation[] annotations = containers.findRepeatedAnnotations(element.getAnnotation(annotationType));
 		return extractValues(annotations);
 	}
 
-	private Object[] extractValues(Annotation[] annotations) {
-		try {
-			if (annotations == null) {
-				return null;
-			}
-			Object[] result = new String[annotations.length];
-			for (int i = 0; i < annotations.length; i++) {
-				result[i] = annotations[i].annotationType().getMethod("value").invoke(
-						annotations[i]);
-			}
-			return result;
-		}
-		catch (Exception ex) {
-			throw new RuntimeException(ex);
+	private static Object[] extractValues(Annotation[] annotations) {
+		if (annotations == null) {
+			return null;
 		}
+		return Arrays.stream(annotations).map(AnnotationUtils::getValue).toArray(Object[]::new);
 	}
 
-	@Retention(RetentionPolicy.RUNTIME)
-	@interface NonRepeatable {
-
-		String value() default "";
-	}
 
 	@Retention(RetentionPolicy.RUNTIME)
-	@Repeatable(StandardContainer.class)
-	@interface StandardRepeatable {
+	@interface NonRepeatable {
 
 		String value() default "";
 	}
@@ -225,7 +200,8 @@ class RepeatableContainersTests {
 	}
 
 	@Retention(RetentionPolicy.RUNTIME)
-	@interface ExplicitRepeatable {
+	@Repeatable(StandardContainer.class)
+	@interface StandardRepeatable {
 
 		String value() default "";
 	}
@@ -236,6 +212,12 @@ class RepeatableContainersTests {
 		ExplicitRepeatable[] value();
 	}
 
+	@Retention(RetentionPolicy.RUNTIME)
+	@interface ExplicitRepeatable {
+
+		String value() default "";
+	}
+
 	@Retention(RetentionPolicy.RUNTIME)
 	@interface InvalidNoValue {
 	}
@@ -253,20 +235,20 @@ class RepeatableContainersTests {
 	}
 
 	@NonRepeatable("a")
-	static class WithNonRepeatable {
+	static class NonRepeatableTestCase {
 	}
 
 	@StandardRepeatable("a")
-	static class WithSingleStandardRepeatable {
+	static class SingleStandardRepeatableTestCase {
 	}
 
 	@StandardRepeatable("a")
 	@StandardRepeatable("b")
-	static class WithStandardRepeatables {
+	static class StandardRepeatablesTestCase {
 	}
 
 	@ExplicitContainer({ @ExplicitRepeatable("a"), @ExplicitRepeatable("b") })
-	static class WithExplicitRepeatables {
+	static class ExplicitRepeatablesTestCase {
 	}
 
 }