Conditionally instantiates java.sql.Date

CHANGELOG.md

@@ -13,6 +13,10 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
+### Fixed
+
+- Instantiates `java.sql.Date` only when available, so EqualsVerifier no longer throws `NoClassDefFoundError` when it's not available. ([Issue 746](https://github.com/jqno/equalsverifier/issues/746))
+
 ## [3.17] - 2024-09-24
 
 ### Added

equalsverifier-core/src/main/java/nl/jqno/equalsverifier/internal/reflection/JavaApiPrefabValues.java

@@ -327,23 +327,28 @@ private void addDateTimeClasses() {
     private void addUncommonClasses() {
         addFactory(ThreadLocal.class, simple(a -> ThreadLocal.withInitial(() -> a), null));
 
+        // Constructing java.sql.* classes reflectively, because they reside in a different module
+        // which causes trouble when running EqualsVerifier on the modulepath.
+        ConditionalInstantiator sqlDate = new ConditionalInstantiator("java.sql.Date");
+        ConditionalInstantiator sqlTime = new ConditionalInstantiator("java.sql.Time");
+        ConditionalInstantiator sqlTimestamp = new ConditionalInstantiator("java.sql.Timestamp");
         addValues(
-            java.sql.Date.class,
-            new java.sql.Date(1337),
-            new java.sql.Date(42),
-            new java.sql.Date(1337)
+            sqlDate.resolve(),
+            sqlDate.instantiate(classes(long.class), objects(1337)),
+            sqlDate.instantiate(classes(long.class), objects(42)),
+            sqlDate.instantiate(classes(long.class), objects(1337))
         );
         addValues(
-            java.sql.Time.class,
-            new java.sql.Time(1337),
-            new java.sql.Time(42),
-            new java.sql.Time(1337)
+            sqlTime.resolve(),
+            sqlTime.instantiate(classes(long.class), objects(1337)),
+            sqlTime.instantiate(classes(long.class), objects(42)),
+            sqlTime.instantiate(classes(long.class), objects(1337))
         );
         addValues(
-            java.sql.Timestamp.class,
-            new java.sql.Timestamp(1337),
-            new java.sql.Timestamp(42),
-            new java.sql.Timestamp(1337)
+            sqlTimestamp.resolve(),
+            sqlTimestamp.instantiate(classes(long.class), objects(1337)),
+            sqlTimestamp.instantiate(classes(long.class), objects(42)),
+            sqlTimestamp.instantiate(classes(long.class), objects(1337))
         );
 
         addValues(EventObject.class, new EventObject(1), new EventObject(2), new EventObject(1));