From 9ef30997113b571f02816dc4e0fd87dd024c4d63 Mon Sep 17 00:00:00 2001
From: Dan Nawrocki <dnawrocki@athenasciences.com>
Date: Mon, 2 Mar 2020 11:59:37 +0100
Subject: [PATCH] DATACMNS-658 - Add IgnoreCase ordering option to
 SortHandlerMethodArgumentResolver.

We now pick up case-insensitive sorting flags by parsing it up from a sort query string argument.

To enable ignore case for one or more properties, we expect "ignorecase" as last element in a sort spec. Sort order and case-sensitivity options are parsed case-insensitive for a greater flexibility:

http://localhost/?sort=firstname,IgnoreCase or http://localhost/?sort=firstname,ASC,ignorecase

Original pull request: #172.
---
 ...tHandlerMethodArgumentResolverSupport.java |  6 +++--
 ...andlerMethodArgumentResolverUnitTests.java | 23 +++++++++++++++++++
 2 files changed, 27 insertions(+), 2 deletions(-)

diff --git a/src/main/java/org/springframework/data/web/SortHandlerMethodArgumentResolverSupport.java b/src/main/java/org/springframework/data/web/SortHandlerMethodArgumentResolverSupport.java
index 422bb297e..3c5ecb237 100644
--- a/src/main/java/org/springframework/data/web/SortHandlerMethodArgumentResolverSupport.java
+++ b/src/main/java/org/springframework/data/web/SortHandlerMethodArgumentResolverSupport.java
@@ -187,8 +187,10 @@ public abstract class SortHandlerMethodArgumentResolverSupport {
 
 	/**
 	 * Parses the given sort expressions into a {@link Sort} instance. The implementation expects the sources to be a
-	 * concatenation of Strings using the given delimiter. If the last element can be parsed into a {@link Direction} it's
-	 * considered a {@link Direction} and a simple property otherwise.
+	 * concatenation of Strings using the given delimiter. If the last element is equal to "ignorecase" (when using a
+	 * case-insensitive comparison), the sort order will be performed without respect to case. If the last element (or the
+	 * penultimate element if the last is "ignorecase") can be parsed into a {@link Direction} it's considered a
+	 * {@link Direction} and a simple property otherwise.
 	 *
 	 * @param source will never be {@literal null}.
 	 * @param delimiter the delimiter to be used to split up the source elements, will never be {@literal null}.
diff --git a/src/test/java/org/springframework/data/web/SortHandlerMethodArgumentResolverUnitTests.java b/src/test/java/org/springframework/data/web/SortHandlerMethodArgumentResolverUnitTests.java
index dc29316ce..1bd12455a 100755
--- a/src/test/java/org/springframework/data/web/SortHandlerMethodArgumentResolverUnitTests.java
+++ b/src/test/java/org/springframework/data/web/SortHandlerMethodArgumentResolverUnitTests.java
@@ -18,6 +18,7 @@ package org.springframework.data.web;
 import static org.assertj.core.api.Assertions.*;
 import static org.springframework.data.domain.Sort.Direction.*;
 
+import java.util.Arrays;
 import java.util.stream.Stream;
 
 import javax.servlet.http.HttpServletRequest;
@@ -74,6 +75,28 @@ public class SortHandlerMethodArgumentResolverUnitTests extends SortDefaultUnitT
 		assertThat(sort.isSorted()).isFalse();
 	}
 
+	@Test
+	public void sortParamHandlesSortOrderAndIgnoreCase() throws Exception {
+
+		MockHttpServletRequest request = new MockHttpServletRequest();
+		request.addParameter("sort", "property,DESC,IgnoreCase");
+		request.addParameter("sort", "");
+
+		assertThat(resolveSort(request, PARAMETER))
+				.isEqualTo(Sort.by(Arrays.asList(new Order(DESC, "property").ignoreCase())));
+	}
+
+	@Test
+	public void sortParamHandlesIgnoreCase() throws Exception {
+
+		MockHttpServletRequest request = new MockHttpServletRequest();
+		request.addParameter("sort", "property,IgnoreCase");
+		request.addParameter("sort", "");
+
+		assertThat(resolveSort(request, PARAMETER))
+				.isEqualTo(Sort.by(Arrays.asList(new Order(ASC, "property").ignoreCase())));
+	}
+
 	@Test
 	public void discoversSimpleSortFromRequest() {