1 files changed, 103 insertions, 0 deletions
diff --git a/src/test/java/com/code_intelligence/jazzer/mutation/mutator/lang/EnumMutatorTest.java b/src/test/java/com/code_intelligence/jazzer/mutation/mutator/lang/EnumMutatorTest.java
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+++ b/src/test/java/com/code_intelligence/jazzer/mutation/mutator/lang/EnumMutatorTest.java
@@ -0,0 +1,103 @@
+/*
+ * 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 static org.junit.jupiter.api.Assertions.assertThrows;
+
+import com.code_intelligence.jazzer.mutation.annotation.NotNull;
+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.io.ByteArrayInputStream;
+import java.io.ByteArrayOutputStream;
+import java.io.DataInputStream;
+import java.io.DataOutputStream;
+import java.io.IOException;
+import org.junit.jupiter.api.Test;
+
+class EnumMutatorTest {
+  enum TestEnumOne { A }
+
+  enum TestEnum { A, B, C }
+
+  @Test
+  void testBoxed() {
+    SerializingMutator<TestEnum> mutator =
+        (SerializingMutator<TestEnum>) LangMutators.newFactory().createOrThrow(
+            new TypeHolder<@NotNull TestEnum>() {}.annotatedType());
+    assertThat(mutator.toString()).isEqualTo("Enum<TestEnum>");
+    TestEnum cl;
+    try (MockPseudoRandom prng = mockPseudoRandom(0)) {
+      cl = mutator.init(prng);
+    }
+    assertThat(cl).isEqualTo(TestEnum.A);
+
+    try (MockPseudoRandom prng = mockPseudoRandom(1)) {
+      cl = mutator.mutate(cl, prng);
+    }
+    assertThat(cl).isEqualTo(TestEnum.B);
+
+    try (MockPseudoRandom prng = mockPseudoRandom(0)) {
+      cl = mutator.mutate(cl, prng);
+    }
+    assertThat(cl).isEqualTo(TestEnum.A);
+
+    try (MockPseudoRandom prng = mockPseudoRandom(2)) {
+      cl = mutator.mutate(cl, prng);
+    }
+    assertThat(cl).isEqualTo(TestEnum.C);
+
+    try (MockPseudoRandom prng = mockPseudoRandom(1)) {
+      cl = mutator.mutate(cl, prng);
+    }
+    assertThat(cl).isEqualTo(TestEnum.B);
+  }
+
+  @Test
+  void testEnumWithOneElementShouldThrow() {
+    assertThrows(IllegalArgumentException.class, () -> {
+      LangMutators.newFactory().createOrThrow(
+          new TypeHolder<@NotNull TestEnumOne>() {}.annotatedType());
+    }, "When trying to build mutators for Enum with one value, an Exception should be thrown.");
+  }
+
+  @Test
+  void testEnumBasedOnInvalidInput() throws IOException {
+    SerializingMutator<TestEnum> mutator =
+        (SerializingMutator<TestEnum>) LangMutators.newFactory().createOrThrow(
+            new TypeHolder<@NotNull TestEnum>() {}.annotatedType());
+    ByteArrayOutputStream bo = new ByteArrayOutputStream();
+    DataOutputStream os = new DataOutputStream(bo);
+    // Valid values
+    os.writeInt(0);
+    os.writeInt(1);
+    os.writeInt(2);
+    // Too high indices wrap around
+    os.writeInt(3);
+    // Abs. value is used to calculate the index
+    os.writeInt(-3);
+
+    DataInputStream is = new DataInputStream(new ByteArrayInputStream(bo.toByteArray()));
+    assertThat(mutator.read(is)).isEqualTo(TestEnum.A);
+    assertThat(mutator.read(is)).isEqualTo(TestEnum.B);
+    assertThat(mutator.read(is)).isEqualTo(TestEnum.C);
+    assertThat(mutator.read(is)).isEqualTo(TestEnum.A);
+    assertThat(mutator.read(is)).isEqualTo(TestEnum.A);
+  }
+}