From 6a7c4fc17c6acf0cbc4fed2ce8f333a604b5f369 Mon Sep 17 00:00:00 2001
From: Christoph Strobl <christoph.strobl@broadcom.com>
Date: Thu, 7 Dec 2023 09:53:54 +0100
Subject: [PATCH] Add test to verify map keys retain order when mapped.

See: #4577
Original pull request: #4568
---
 .../core/convert/QueryMapperUnitTests.java        | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

diff --git a/spring-data-mongodb/src/test/java/org/springframework/data/mongodb/core/convert/QueryMapperUnitTests.java b/spring-data-mongodb/src/test/java/org/springframework/data/mongodb/core/convert/QueryMapperUnitTests.java
index 88984baa1..b0d72fd06 100755
--- a/spring-data-mongodb/src/test/java/org/springframework/data/mongodb/core/convert/QueryMapperUnitTests.java
+++ b/spring-data-mongodb/src/test/java/org/springframework/data/mongodb/core/convert/QueryMapperUnitTests.java
@@ -28,6 +28,7 @@ import java.util.Collections;
 import java.util.List;
 import java.util.Map;
 import java.util.Optional;
+import java.util.TreeMap;
 
 import org.bson.conversions.Bson;
 import org.bson.types.Code;
@@ -1517,6 +1518,20 @@ public class QueryMapperUnitTests {
 		assertThat(mappedObject).isEqualTo("{ 'field.name.with.dots' : 'A' }");
 	}
 
+	@Test // GH-4577
+	void mappingShouldRetainMapKeyOrder() {
+
+		TreeMap<String, String> sourceMap = new TreeMap<>(Map.of("test1", "123", "test2", "456"));
+
+		org.bson.Document target = mapper.getMappedObject(query(where("simpleMap").is(sourceMap)).getQueryObject(),
+				context.getPersistentEntity(WithSimpleMap.class));
+		assertThat(target.get("simpleMap", Map.class)).containsExactlyEntriesOf(sourceMap);
+	}
+
+	class WithSimpleMap {
+		Map<String, String> simpleMap;
+	}
+
 	class WithDeepArrayNesting {
 
 		List<WithNestedArray> level0;