1 files changed, 101 insertions, 0 deletions
diff --git a/src/test/java/com/code_intelligence/jazzer/mutation/mutator/lang/NullableMutatorTest.java b/src/test/java/com/code_intelligence/jazzer/mutation/mutator/lang/NullableMutatorTest.java
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+++ b/src/test/java/com/code_intelligence/jazzer/mutation/mutator/lang/NullableMutatorTest.java
@@ -0,0 +1,101 @@
+/*
+ * Copyright 2023 Code Intelligence GmbH
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.code_intelligence.jazzer.mutation.mutator.lang;
+
+import static com.code_intelligence.jazzer.mutation.support.TestSupport.mockPseudoRandom;
+import static com.google.common.truth.Truth.assertThat;
+
+import com.code_intelligence.jazzer.mutation.annotation.NotNull;
+import com.code_intelligence.jazzer.mutation.api.ChainedMutatorFactory;
+import com.code_intelligence.jazzer.mutation.api.SerializingMutator;
+import com.code_intelligence.jazzer.mutation.support.TestSupport.MockPseudoRandom;
+import com.code_intelligence.jazzer.mutation.support.TypeHolder;
+import java.lang.reflect.AnnotatedType;
+import org.junit.jupiter.api.Test;
+
+@SuppressWarnings("unchecked")
+class NullableMutatorTest {
+  @Test
+  void testNullable() {
+    SerializingMutator<Boolean> mutator =
+        new ChainedMutatorFactory(new NullableMutatorFactory(), new BooleanMutatorFactory())
+            .createOrThrow(Boolean.class);
+    assertThat(mutator.toString()).isEqualTo("Nullable<Boolean>");
+
+    Boolean bool;
+    try (MockPseudoRandom prng = mockPseudoRandom(/* init to null */ true)) {
+      bool = mutator.init(prng);
+    }
+    assertThat(bool).isNull();
+
+    try (MockPseudoRandom prng = mockPseudoRandom(/* init for non-null Boolean */ false)) {
+      bool = mutator.mutate(bool, prng);
+    }
+    assertThat(bool).isFalse();
+
+    try (MockPseudoRandom prng = mockPseudoRandom(/* mutate to non-null Boolean */ false)) {
+      bool = mutator.mutate(bool, prng);
+    }
+    assertThat(bool).isTrue();
+
+    try (MockPseudoRandom prng = mockPseudoRandom(/* mutate to null */ true)) {
+      bool = mutator.mutate(bool, prng);
+    }
+    assertThat(bool).isNull();
+  }
+
+  @Test
+  void testNotNull() {
+    ChainedMutatorFactory factory =
+        new ChainedMutatorFactory(new NullableMutatorFactory(), new BooleanMutatorFactory());
+    AnnotatedType notNullBoolean = new TypeHolder<@NotNull Boolean>() {}.annotatedType();
+    SerializingMutator<Boolean> mutator =
+        (SerializingMutator<Boolean>) factory.createOrThrow(notNullBoolean);
+    assertThat(mutator.toString()).isEqualTo("Boolean");
+  }
+
+  @Test
+  void testPrimitive() {
+    ChainedMutatorFactory factory =
+        new ChainedMutatorFactory(new NullableMutatorFactory(), new BooleanMutatorFactory());
+    SerializingMutator<Boolean> mutator = factory.createOrThrow(boolean.class);
+    assertThat(mutator.toString()).isEqualTo("Boolean");
+  }
+
+  @Test
+  void testCrossOver() {
+    SerializingMutator<Boolean> mutator =
+        new ChainedMutatorFactory(new NullableMutatorFactory(), new BooleanMutatorFactory())
+            .createOrThrow(Boolean.class);
+    try (MockPseudoRandom prng = mockPseudoRandom(true)) {
+      Boolean valueCrossedOver = mutator.crossOver(Boolean.TRUE, Boolean.TRUE, prng);
+      assertThat(valueCrossedOver).isNotNull();
+    }
+    try (MockPseudoRandom prng = mockPseudoRandom()) {
+      Boolean bothNull = mutator.crossOver(null, null, prng);
+      assertThat(bothNull).isNull();
+    }
+    try (MockPseudoRandom prng = mockPseudoRandom(false)) {
+      Boolean oneNotNull = mutator.crossOver(null, Boolean.TRUE, prng);
+      assertThat(oneNotNull).isNotNull();
+    }
+    try (MockPseudoRandom prng = mockPseudoRandom(true)) {
+      Boolean nullFrequency = mutator.crossOver(null, Boolean.TRUE, prng);
+      assertThat(nullFrequency).isNull();
+    }
+  }
+}