From 7432a96b48bff92cad8ea298411b32396210cd19 Mon Sep 17 00:00:00 2001
From: Sam Brannen <104798+sbrannen@users.noreply.github.com>
Date: Mon, 11 Dec 2023 13:42:03 +0100
Subject: [PATCH] Polish contribution

See gh-31808
---
 ...aratorsTest.java => ComparatorsTests.java} | 35 +++++++++++++------
 .../comparator/NullSafeComparatorTests.java   | 13 +++++--
 2 files changed, 34 insertions(+), 14 deletions(-)
 rename spring-core/src/test/java/org/springframework/util/comparator/{ComparatorsTest.java => ComparatorsTests.java} (61%)

diff --git a/spring-core/src/test/java/org/springframework/util/comparator/ComparatorsTest.java b/spring-core/src/test/java/org/springframework/util/comparator/ComparatorsTests.java
similarity index 61%
rename from spring-core/src/test/java/org/springframework/util/comparator/ComparatorsTest.java
rename to spring-core/src/test/java/org/springframework/util/comparator/ComparatorsTests.java
index 930f556caa..ca53f68513 100644
--- a/spring-core/src/test/java/org/springframework/util/comparator/ComparatorsTest.java
+++ b/spring-core/src/test/java/org/springframework/util/comparator/ComparatorsTests.java
@@ -21,31 +21,44 @@ import org.junit.jupiter.api.Test;
 import static org.assertj.core.api.Assertions.assertThat;
 
 /**
- * Tests for {@link Comparators}
+ * Tests for {@link Comparators}.
+ *
+ * @since 6.1.2
+ * @author Mathieu Amblard
+ * @author Sam Brannen
  */
-class ComparatorsTest {
+class ComparatorsTests {
 
 	@Test
-	void shouldCompareWithNullsLow() {
-		assertThat(Comparators.nullsLow().compare(null, "boo")).isNegative();
+	void nullsLow() {
+		assertThat(Comparators.nullsLow().compare("boo", "boo")).isZero();
 		assertThat(Comparators.nullsLow().compare(null, null)).isZero();
+		assertThat(Comparators.nullsLow().compare(null, "boo")).isNegative();
+		assertThat(Comparators.nullsLow().compare("boo", null)).isPositive();
 	}
 
 	@Test
-	void shouldCompareWithNullsLowAndComparator() {
-		assertThat(Comparators.nullsLow(String::compareTo).compare(null, "boo")).isNegative();
+	void nullsLowWithExplicitComparator() {
+		assertThat(Comparators.nullsLow(String::compareTo).compare("boo", "boo")).isZero();
 		assertThat(Comparators.nullsLow(String::compareTo).compare(null, null)).isZero();
+		assertThat(Comparators.nullsLow(String::compareTo).compare(null, "boo")).isNegative();
+		assertThat(Comparators.nullsLow(String::compareTo).compare("boo", null)).isPositive();
 	}
 
 	@Test
-	void shouldCompareWithNullsHigh() {
-		assertThat(Comparators.nullsHigh().compare(null, "boo")).isPositive();
+	void nullsHigh() {
+		assertThat(Comparators.nullsHigh().compare("boo", "boo")).isZero();
 		assertThat(Comparators.nullsHigh().compare(null, null)).isZero();
+		assertThat(Comparators.nullsHigh().compare(null, "boo")).isPositive();
+		assertThat(Comparators.nullsHigh().compare("boo", null)).isNegative();
 	}
 
 	@Test
-	void shouldCompareWithNullsHighAndComparator() {
-		assertThat(Comparators.nullsHigh(String::compareTo).compare(null, "boo")).isPositive();
+	void nullsHighWithExplicitComparator() {
+		assertThat(Comparators.nullsHigh(String::compareTo).compare("boo", "boo")).isZero();
 		assertThat(Comparators.nullsHigh(String::compareTo).compare(null, null)).isZero();
+		assertThat(Comparators.nullsHigh(String::compareTo).compare(null, "boo")).isPositive();
+		assertThat(Comparators.nullsHigh(String::compareTo).compare("boo", null)).isNegative();
 	}
-}
\ No newline at end of file
+
+}
diff --git a/spring-core/src/test/java/org/springframework/util/comparator/NullSafeComparatorTests.java b/spring-core/src/test/java/org/springframework/util/comparator/NullSafeComparatorTests.java
index 46ee59fa5b..8b8f45a2cc 100644
--- a/spring-core/src/test/java/org/springframework/util/comparator/NullSafeComparatorTests.java
+++ b/spring-core/src/test/java/org/springframework/util/comparator/NullSafeComparatorTests.java
@@ -36,7 +36,11 @@ class NullSafeComparatorTests {
 	void shouldCompareWithNullsLow() {
 		@SuppressWarnings("deprecation")
 		Comparator<String> c = NullSafeComparator.NULLS_LOW;
-		assertThat(c.compare(null, "boo")).isLessThan(0);
+
+		assertThat(c.compare("boo", "boo")).isZero();
+		assertThat(c.compare(null, null)).isZero();
+		assertThat(c.compare(null, "boo")).isNegative();
+		assertThat(c.compare("boo", null)).isPositive();
 	}
 
 	@Test
@@ -44,8 +48,11 @@ class NullSafeComparatorTests {
 	void shouldCompareWithNullsHigh() {
 		@SuppressWarnings("deprecation")
 		Comparator<String> c = NullSafeComparator.NULLS_HIGH;
-		assertThat(c.compare(null, "boo")).isGreaterThan(0);
-		assertThat(c.compare(null, null)).isEqualTo(0);
+
+		assertThat(c.compare("boo", "boo")).isZero();
+		assertThat(c.compare(null, null)).isZero();
+		assertThat(c.compare(null, "boo")).isPositive();
+		assertThat(c.compare("boo", null)).isNegative();
 	}
 
 }