From 89b2aa162afc9f49c6319929106af28eec8eb34a Mon Sep 17 00:00:00 2001
From: Michael Hunger <github@jexp.de>
Date: Mon, 10 Oct 2011 10:29:49 +0200
Subject: [PATCH] DATACMNS-85 - Extended PersistentPropertyPath with
 getLength() and getParentPath().

---
 .../DefaultPersistentPropertyPath.java        | 16 ++++++++++
 .../context/PersistentPropertyPath.java       | 15 +++++++++
 .../DefaultPersistenPropertyPathUnitTest.java | 31 +++++++++++++++----
 3 files changed, 56 insertions(+), 6 deletions(-)

diff --git a/spring-data-commons-core/src/main/java/org/springframework/data/mapping/context/DefaultPersistentPropertyPath.java b/spring-data-commons-core/src/main/java/org/springframework/data/mapping/context/DefaultPersistentPropertyPath.java
index fd4ce11c3..5e2d225af 100644
--- a/spring-data-commons-core/src/main/java/org/springframework/data/mapping/context/DefaultPersistentPropertyPath.java
+++ b/spring-data-commons-core/src/main/java/org/springframework/data/mapping/context/DefaultPersistentPropertyPath.java
@@ -164,6 +164,13 @@ class DefaultPersistentPropertyPath<T extends PersistentProperty<T>> implements
 		return new DefaultPersistentPropertyPath<T>(properties);
 	}
 
+    public PersistentPropertyPath<T> getParentPath() {
+        int size = properties.size();
+        if (size <= 1) {
+            return this;
+        }
+        return new DefaultPersistentPropertyPath<T>(properties.subList(0,size-1));
+    }
 	/* 
 	 * (non-Javadoc)
 	 * @see java.lang.Iterable#iterator()
@@ -200,4 +207,13 @@ class DefaultPersistentPropertyPath<T extends PersistentProperty<T>> implements
 	public int hashCode() {
 		return properties.hashCode();
 	}
+
+    @Override
+    public String toString() {
+        return toDotPath();
+    }
+
+    public int getLength() {
+        return properties.size();
+    }
 }
diff --git a/spring-data-commons-core/src/main/java/org/springframework/data/mapping/context/PersistentPropertyPath.java b/spring-data-commons-core/src/main/java/org/springframework/data/mapping/context/PersistentPropertyPath.java
index 4cfe13c5c..f9f8acde3 100644
--- a/spring-data-commons-core/src/main/java/org/springframework/data/mapping/context/PersistentPropertyPath.java
+++ b/spring-data-commons-core/src/main/java/org/springframework/data/mapping/context/PersistentPropertyPath.java
@@ -95,4 +95,19 @@ public interface PersistentPropertyPath<T extends PersistentProperty<T>> extends
 	 * @return
 	 */
 	PersistentPropertyPath<T> getExtensionForBaseOf(PersistentPropertyPath<T> base);
+
+	/**
+	 * Returns the parent path of the current {@link PersistentPropertyPath}, i.e. the path without the leaf property. This happens up to the base
+	 * property. So for a direct property reference calling this method will result in returning the property.
+	 * 
+	 * @return
+	 */
+	PersistentPropertyPath<T> getParentPath();
+
+	/**
+	 * Returns the length of the {@link PersistentPropertyPath}.
+	 * 
+	 * @return
+	 */
+	int getLength();
 }
\ No newline at end of file
diff --git a/spring-data-commons-core/src/test/java/org/springframework/data/mapping/context/DefaultPersistenPropertyPathUnitTest.java b/spring-data-commons-core/src/test/java/org/springframework/data/mapping/context/DefaultPersistenPropertyPathUnitTest.java
index 3644d5b20..81088b1c0 100644
--- a/spring-data-commons-core/src/test/java/org/springframework/data/mapping/context/DefaultPersistenPropertyPathUnitTest.java
+++ b/spring-data-commons-core/src/test/java/org/springframework/data/mapping/context/DefaultPersistenPropertyPathUnitTest.java
@@ -21,6 +21,7 @@ import static org.mockito.Matchers.*;
 import static org.mockito.Mockito.*;
 
 import java.util.Arrays;
+import java.util.Collections;
 
 import org.junit.Before;
 import org.junit.Test;
@@ -29,7 +30,6 @@ import org.mockito.Mock;
 import org.mockito.runners.MockitoJUnitRunner;
 import org.springframework.core.convert.converter.Converter;
 import org.springframework.data.mapping.PersistentProperty;
-import org.springframework.data.mapping.context.PersistentPropertyPath;
 
 /**
  * Unit tests for {@link DefaultPersistentPropertyPath}.
@@ -44,13 +44,15 @@ public class DefaultPersistenPropertyPathUnitTest<T extends PersistentProperty<T
 
 	@Mock
 	Converter<T, String> converter;
-	
+
+	PersistentPropertyPath<T> noLeg;
 	PersistentPropertyPath<T> oneLeg;
 	PersistentPropertyPath<T> twoLegs;
-	
+
 	@Before
 	@SuppressWarnings("unchecked")
 	public void setUp() {
+		noLeg = new DefaultPersistentPropertyPath<T>(Collections.<T> emptyList());
 		oneLeg = new DefaultPersistentPropertyPath<T>(Arrays.asList(first));
 		twoLegs = new DefaultPersistentPropertyPath<T>(Arrays.asList(first, second));
 	}
@@ -84,7 +86,7 @@ public class DefaultPersistenPropertyPathUnitTest<T extends PersistentProperty<T
 		assertThat(twoLegs.getLeafProperty(), is(second));
 		assertThat(oneLeg.getLeafProperty(), is(first));
 	}
-	
+
 	@Test
 	public void returnsCorrectBaseProperty() {
 
@@ -98,12 +100,29 @@ public class DefaultPersistenPropertyPathUnitTest<T extends PersistentProperty<T
 		assertThat(oneLeg.isBasePathOf(twoLegs), is(true));
 		assertThat(twoLegs.isBasePathOf(oneLeg), is(false));
 	}
-	
+
 	@Test
 	@SuppressWarnings("unchecked")
 	public void calculatesExtensionCorrectly() {
-		
+
 		PersistentPropertyPath<T> extension = twoLegs.getExtensionForBaseOf(oneLeg);
 		assertThat(extension, is((PersistentPropertyPath<T>) new DefaultPersistentPropertyPath<T>(Arrays.asList(second))));
 	}
+
+	@Test
+	public void returnsTheCorrectParentPath() {
+		assertThat(twoLegs.getParentPath(), is(oneLeg));
+	}
+
+	@Test
+	public void returnsItselfAsParentPathIfSizeOne() {
+		assertThat(oneLeg.getParentPath(), is(oneLeg));
+	}
+
+	@Test
+	public void pathReturnsCorrectSize() {
+		assertThat(noLeg.getLength(), is(0));
+		assertThat(oneLeg.getLength(), is(1));
+		assertThat(twoLegs.getLength(), is(2));
+	}
 }