Use exact matching for IN clause with ignore case.

Prior to this change the generated pattern would have matched more entries than it should have. The behavior is now aligned to its counterpart not using the IgnoreCase flag.

Closes #4404
Original pull request: #4412

Author: christophstrobl

spring-data-mongodb/src/main/java/org/springframework/data/mongodb/core/query/MongoRegexCreator.java

@@ -107,7 +107,9 @@ public String toRegularExpression(@Nullable String source, @Nullable MatchMode m
 	 * @param source
 	 * @return
 	 * @since 2.2.14
+	 * @deprecated since 4.0.7
 	 */
+	@Deprecated(since = "4.0.7", forRemoval = true)
 	public Object toCaseInsensitiveMatch(Object source) {
 		return source instanceof String ? new BsonRegularExpression(Pattern.quote((String) source), "i") : source;
 	}

spring-data-mongodb/src/main/java/org/springframework/data/mongodb/repository/query/MongoQueryCreator.java

@@ -25,7 +25,7 @@
 
 import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
-
+import org.bson.BsonRegularExpression;
 import org.springframework.data.domain.Range;
 import org.springframework.data.domain.Range.Bound;
 import org.springframework.data.domain.Sort;
@@ -390,7 +390,18 @@ private java.util.List<?> nextAsList(Iterator<Object> iterator, Part part) {
 
 		Streamable<?> streamable = asStreamable(iterator.next());
 		if (!isSimpleComparisionPossible(part)) {
-			streamable = streamable.map(MongoRegexCreator.INSTANCE::toCaseInsensitiveMatch);
+
+			MatchMode matchMode = toMatchMode(part.getType());
+			String regexOptions = toRegexOptions(part);
+
+			streamable = streamable.map(it -> {
+				if (it instanceof String value) {
+
+					return new BsonRegularExpression(MongoRegexCreator.INSTANCE.toRegularExpression(value, matchMode),
+							regexOptions);
+				}
+				return it;
+			});
 		}
 
 		return streamable.toList();
@@ -482,6 +493,7 @@ private static MatchMode toMatchMode(Type type) {
 				return MatchMode.REGEX;
 			case NEGATING_SIMPLE_PROPERTY:
 			case SIMPLE_PROPERTY:
+			case IN:
 				return MatchMode.EXACT;
 			default:
 				return MatchMode.DEFAULT;

spring-data-mongodb/src/test/java/org/springframework/data/mongodb/repository/AbstractPersonRepositoryIntegrationTests.java

@@ -1451,9 +1451,16 @@ void findByUnwrapped() {
 		assertThat(result.get(0).getId().equals(bart.getId()));
 	}
 
-	@Test // GH-3395
+	@Test // GH-3395, GH-4404
 	void caseInSensitiveInClause() {
+
 		assertThat(repository.findByLastnameIgnoreCaseIn("bEAuFoRd", "maTTheWs")).hasSize(3);
+
+		repository.save(new Person("the-first", "The First"));
+		repository.save(new Person("the-first-one", "The First One"));
+		repository.save(new Person("the-second", "The Second"));
+
+		assertThat(repository.findByLastnameIgnoreCaseIn("tHE fIRsT")).hasSize(1);
 	}
 
 	@Test // GH-3395

spring-data-mongodb/src/test/java/org/springframework/data/mongodb/repository/query/MongoQueryCreatorUnitTests.java

@@ -25,6 +25,7 @@
 import java.util.List;
 import java.util.regex.Pattern;
 
+import org.bson.BsonRegularExpression;
 import org.bson.Document;
 import org.bson.types.ObjectId;
 import org.junit.jupiter.api.BeforeEach;
@@ -273,6 +274,17 @@ void createsQueryWithFindByIgnoreCaseCorrectly() {
 		assertThat(query).isEqualTo(query(where("firstName").regex("^dave$", "i")));
 	}
 
+	@Test // GH-4404
+	void createsQueryWithFindByInClauseHavingIgnoreCaseCorrectly() {
+
+		PartTree tree = new PartTree("findAllByFirstNameInIgnoreCase", Person.class);
+		MongoQueryCreator creator = new MongoQueryCreator(tree, getAccessor(converter, List.of("da've", "carter")), context);
+
+		Query query = creator.createQuery();
+		assertThat(query).isEqualTo(query(where("firstName")
+				.in(List.of(new BsonRegularExpression("^\\Qda've\\E$", "i"), new BsonRegularExpression("^carter$", "i")))));
+	}
+
 	@Test // DATAMONGO-770
 	void createsQueryWithFindByNotIgnoreCaseCorrectly() {