DATAREST-995 - Fixed detection of collection append operations for JSON Patch requests.

We previously erroneously looked for a ~ in a JSON Pointer to indicate collection append in e.g. an add operation. We now also support the actually correct - keeping the original behavior for now to not break clients that currently make use of it.

Author: odrotbohm

spring-data-rest-webmvc/src/main/java/org/springframework/data/rest/webmvc/json/patch/PatchOperation.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2014-2016 the original author or authors.
+ * Copyright 2014-2017 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.
@@ -189,7 +189,7 @@ private Integer targetListIndex(String path) {
 		String[] pathNodes = path.split("\\/");
 		String lastNode = pathNodes[pathNodes.length - 1];
 
-		if ("~".equals(lastNode)) {
+		if (APPEND_CHARACTERS.contains(lastNode)) {
 			return -1;
 		}
 

spring-data-rest-webmvc/src/main/java/org/springframework/data/rest/webmvc/json/patch/PathToSpEL.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2014-2016 the original author or authors.
+ * Copyright 2014-2017 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.
@@ -16,6 +16,7 @@
 package org.springframework.data.rest.webmvc.json.patch;
 
 import java.util.Arrays;
+import java.util.List;
 
 import org.springframework.expression.Expression;
 import org.springframework.expression.spel.standard.SpelExpressionParser;
@@ -30,6 +31,7 @@
 public class PathToSpEL {
 
 	private static final SpelExpressionParser SPEL_EXPRESSION_PARSER = new SpelExpressionParser();
+	static final List<String> APPEND_CHARACTERS = Arrays.asList("-", "~");
 
 	/**
 	 * Converts a patch path to an {@link Expression}.
@@ -55,7 +57,7 @@ public static Expression spelToExpression(String spel) {
 	 * Produces an expression targeting the parent of the object that the given path targets.
 	 * 
 	 * @param path the path to find a parent expression for.
-	 * @return an {@link Expression} targeting the parent of the object specifed by path.
+	 * @return an {@link Expression} targeting the parent of the object specified by path.
 	 */
 	public static Expression pathToParentExpression(String path) {
 		return spelToExpression(pathNodesToSpEL(copyOf(path.split("\\/"), path.split("\\/").length - 1)));
@@ -76,7 +78,7 @@ private static String pathNodesToSpEL(String[] pathNodes) {
 				continue;
 			}
 
-			if ("~".equals(pathNode)) {
+			if (APPEND_CHARACTERS.contains(pathNode)) {
 				spelBuilder.append("[size() - 1]");
 				continue;
 			}

spring-data-rest-webmvc/src/test/java/org/springframework/data/rest/webmvc/json/patch/AddOperationTests.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2014-2016 the original author or authors.
+ * Copyright 2014-2017 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.
@@ -15,6 +15,7 @@
  */
 package org.springframework.data.rest.webmvc.json.patch;
 
+import static org.hamcrest.CoreMatchers.*;
 import static org.junit.Assert.*;
 
 import java.util.ArrayList;
@@ -73,4 +74,14 @@ public void addItemToList() throws Exception {
 		assertEquals("C", todos.get(3).getDescription());
 		assertFalse(todos.get(3).isComplete());
 	}
+
+	@Test // DATAREST-995
+	public void addsItemsToNestedList() {
+
+		Todo todo = new Todo(1L, "description", false);
+
+		new AddOperation("/items/-", "Some text.").perform(todo, Todo.class);
+
+		assertThat(todo.getItems().get(0), is("Some text."));
+	}
 }