Throw exception when json-patch append adds primitive to collection o…

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

@@ -64,7 +64,13 @@ protected Object evaluateValueFromTarget(Object targetObject, Class<?> entityTyp
 	}
 
 	protected final Object evaluate(Class<?> type) {
-		return value instanceof LateObjectEvaluator ? ((LateObjectEvaluator) value).evaluate(type) : value;
+		if (value instanceof LateObjectEvaluator) {
+			return ((LateObjectEvaluator) value).evaluate(type);
+		}
+		if (value.getClass() != type) {
+			throw new PatchException(String.format("Could not read %s into %s", value, type));
+		}
+		return value;
 	}
 
 	/**

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

@@ -155,6 +155,25 @@ void manipulatesNestedCollectionProperly() {
 		assertThat(outer.todoList.getTodos()).containsExactly(todos.get(0), todos.get(1), newTodo);
 	}
 
+
+	@Test
+	void failPrimitiveInNestedObjectCollection() {
+		List<Todo> todos = new ArrayList<>();
+		todos.add(new Todo(1L, "A", false));
+		todos.add(new Todo(2L, "B", false));
+
+		TodoList todoList = new TodoList();
+		todoList.setTodos(todos);
+
+		assertThatExceptionOfType(PatchException.class)
+				.isThrownBy(() -> AddOperation.of("/todos/-", "Primitive").perform(todoList, TodoList.class, TestPropertyPathContext.INSTANCE))
+				.withMessageContaining("Could not read")
+				.withMessageContaining("into class");
+	}
+
+	@Data
+	@AllArgsConstructor
+	@NoArgsConstructor
 	public static class TodoListWrapper {
 		public TodoList todoList;