Add @UnmappedPropertyValue support

Update @PropertyMapping support to allow single enum values to be marked
as an @UnmappedPropertyValue. This change is primarily so that users can
replace "default" values globally for across all tests.

See gh-6455

spring-boot-test-autoconfigure/src/main/java/org/springframework/boot/test/autoconfigure/properties/AnnotationsPropertySource.java

@@ -17,6 +17,7 @@
 package org.springframework.boot.test.autoconfigure.properties;
 
 import java.lang.annotation.Annotation;
+import java.lang.reflect.Field;
 import java.lang.reflect.Method;
 import java.util.ArrayList;
 import java.util.Collections;
@@ -113,7 +114,9 @@ public class AnnotationsPropertySource extends EnumerablePropertySource<Class<?>
 			String name = getName(typeMapping, attributeMapping, attribute);
 			ReflectionUtils.makeAccessible(attribute);
 			Object value = ReflectionUtils.invokeMethod(attribute, annotation);
-			putProperties(name, value, properties);
+			if (isValueMapped(value)) {
+				putProperties(name, value, properties);
+			}
 		}
 	}
 
@@ -125,6 +128,17 @@ public class AnnotationsPropertySource extends EnumerablePropertySource<Class<?>
 		return (typeMapping != null && typeMapping.map());
 	}
 
+	private boolean isValueMapped(Object value) {
+		if (value != null && value instanceof Enum) {
+			Field field = ReflectionUtils.findField(value.getClass(),
+					((Enum<?>) value).name());
+			if (AnnotatedElementUtils.isAnnotated(field, UnmappedPropertyValue.class)) {
+				return false;
+			}
+		}
+		return true;
+	}
+
 	private String getName(PropertyMapping typeMapping, PropertyMapping attributeMapping,
 			Method attribute) {
 		String prefix = (typeMapping == null ? "" : typeMapping.value());

spring-boot-test-autoconfigure/src/main/java/org/springframework/boot/test/autoconfigure/properties/PropertyMapping.java

@@ -47,6 +47,7 @@ import org.springframework.test.context.TestPropertySource;
  * @author Phillip Webb
  * @since 1.4.0
  * @see AnnotationsPropertySource
+ * @see UnmappedPropertyValue
  * @see TestPropertySource
  */
 @Documented

spring-boot-test-autoconfigure/src/main/java/org/springframework/boot/test/autoconfigure/properties/UnmappedPropertyValue.java

@@ -0,0 +1,36 @@
+/*
+ * Copyright 2012-2016 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
+ *
+ *      http://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.autoconfigure.properties;
+
+import java.lang.annotation.ElementType;
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+import java.lang.annotation.Target;
+
+/**
+ * Indicates that a single value should not be mapped when referenced from a
+ * {@link PropertyMapping @PropertyMapping} annotation.
+ *
+ * @author Phillip Webb
+ * @since 1.4.0
+ * @see PropertyMapping
+ */
+@Retention(RetentionPolicy.RUNTIME)
+@Target({ ElementType.FIELD })
+public @interface UnmappedPropertyValue {
+
+}

spring-boot-test-autoconfigure/src/test/java/org/springframework/boot/test/autoconfigure/properties/AnnotationsPropertySourceTests.java

@@ -185,6 +185,20 @@ public class AnnotationsPropertySourceTests {
 		assertThat(source.getProperty("aliasing.value")).isEqualTo("baz");
 	}
 
+	@Test
+	public void enumValueMapped() throws Exception {
+		AnnotationsPropertySource source = new AnnotationsPropertySource(
+				EnumValueMapped.class);
+		assertThat(source.getProperty("testenum.value")).isEqualTo(EnumItem.TWO);
+	}
+
+	@Test
+	public void enumValueNotMapped() throws Exception {
+		AnnotationsPropertySource source = new AnnotationsPropertySource(
+				EnumValueNotMapped.class);
+		assertThat(source.containsProperty("testenum.value")).isFalse();
+	}
+
 	static class NoAnnotation {
 
 	}
@@ -382,4 +396,32 @@ public class AnnotationsPropertySourceTests {
 
 	}
 
+	@EnumAnnotation(EnumItem.TWO)
+	static class EnumValueMapped {
+
+	}
+
+	@EnumAnnotation(EnumItem.DEFAULT)
+	static class EnumValueNotMapped {
+
+	}
+
+	@Retention(RetentionPolicy.RUNTIME)
+	@PropertyMapping("testenum")
+	static @interface EnumAnnotation {
+
+		EnumItem value();
+
+	}
+
+	enum EnumItem {
+
+		@UnmappedPropertyValue DEFAULT,
+
+		ONE,
+
+		TWO
+
+	}
+
 }