Add tests for RandomGenerator-s of factory methods.

Bug: 323464259
Bug: 323463671
Bug: 323464364

Test: CtsLibcoreTestCases
Change-Id: I6f7f30be15250d9b5c4de166ef67397de97fc203

1 files changed, 12 insertions, 0 deletions

diff --git a/luni/src/test/java/libcore/java/util/random/RandomGeneratorTest.java b/luni/src/test/java/libcore/java/util/random/RandomGeneratorTest.java
index fb6828093d0..999522f1a7d 100644
--- a/luni/src/test/java/libcore/java/util/random/RandomGeneratorTest.java
+++ b/luni/src/test/java/libcore/java/util/random/RandomGeneratorTest.java
@@ -54,4 +54,16 @@ public class RandomGeneratorTest {
             .forEach(RandomGenerator::isDeprecated);
     }
 
+    @Test
+    public void of_factoryMethod_throwsNPE() {
+        assertThrows(NullPointerException.class,
+            () -> RandomGenerator.ArbitrarilyJumpableGenerator.of(null));
+
+        assertThrows(NullPointerException.class,
+            () -> RandomGenerator.JumpableGenerator.of(null));
+
+        assertThrows(NullPointerException.class,
+            () -> RandomGenerator.StreamableGenerator.of(null));
+    }
+
 }