1 files changed, 47 insertions, 0 deletions
diff --git a/src/main/java/com/code_intelligence/jazzer/mutation/mutator/lang/EnumMutatorFactory.java b/src/main/java/com/code_intelligence/jazzer/mutation/mutator/lang/EnumMutatorFactory.java
new file mode 100644
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+++ b/src/main/java/com/code_intelligence/jazzer/mutation/mutator/lang/EnumMutatorFactory.java
@@ -0,0 +1,47 @@
+/*
+ * 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.combinator.MutatorCombinators.mutateIndices;
+import static com.code_intelligence.jazzer.mutation.combinator.MutatorCombinators.mutateThenMap;
+import static com.code_intelligence.jazzer.mutation.combinator.MutatorCombinators.mutateThenMapToImmutable;
+import static com.code_intelligence.jazzer.mutation.support.Preconditions.require;
+import static com.code_intelligence.jazzer.mutation.support.TypeSupport.asSubclassOrEmpty;
+
+import com.code_intelligence.jazzer.mutation.api.Debuggable;
+import com.code_intelligence.jazzer.mutation.api.MutatorFactory;
+import com.code_intelligence.jazzer.mutation.api.SerializingMutator;
+import java.lang.reflect.AnnotatedType;
+import java.util.Optional;
+import java.util.function.Predicate;
+
+final class EnumMutatorFactory extends MutatorFactory {
+  @Override
+  public Optional<SerializingMutator<?>> tryCreate(AnnotatedType type, MutatorFactory factory) {
+    return asSubclassOrEmpty(type, Enum.class).map(parent -> {
+      require(((Class<Enum<?>>) type.getType()).getEnumConstants().length > 1,
+          String.format(
+              "%s defines less than two enum constants and can't be mutated. Use a constant instead.",
+              parent));
+      Enum<?>[] values = ((Class<Enum<?>>) type.getType()).getEnumConstants();
+      return mutateThenMap(mutateIndices(values.length),
+          (index)
+              -> values[index],
+          Enum::ordinal, (Predicate<Debuggable> inCycle) -> "Enum<" + parent.getSimpleName() + ">");
+    });
+  }
+}