feat: add set mutator

Author: oetr

selffuzz/src/test/java/com/code_intelligence/selffuzz/mutation/ArgumentsMutatorFuzzTest.java

@@ -42,6 +42,7 @@
 import java.util.Arrays;
 import java.util.List;
 import java.util.Map;
+import java.util.Set;
 import java.util.stream.Collectors;
 
 public class ArgumentsMutatorFuzzTest {
@@ -109,6 +110,13 @@ void fuzzListOfMaps(@WithSize(max = 4) Map<String, Integer> nullableMap) {
     }
   }
 
+  @SelfFuzzTest
+  void fuzzListOfSets(@WithSize(max = 10) @NotNull Set<@NotNull Integer> setWithSize) {
+    if (setWithSize != null) {
+      assertThat(setWithSize.size()).isAtMost(10);
+    }
+  }
+
   @SelfFuzzTest
   void fuzzListOfLists(List<@NotNull List<String>> nullableMap, List<List<Integer>> nullableList) {}
 

src/main/java/com/code_intelligence/jazzer/mutation/annotation/WithSize.java

@@ -26,6 +26,7 @@
 import java.lang.annotation.Target;
 import java.util.List;
 import java.util.Map;
+import java.util.Set;
 
 /**
  * Generates a {@link List} or {@link Map} with the specified size.
@@ -35,7 +36,7 @@
  */
 @Target(TYPE_USE)
 @Retention(RUNTIME)
-@AppliesTo({List.class, Map.class})
+@AppliesTo({List.class, Map.class, Set.class})
 @ValidateContainerDimensions
 @PropertyConstraint
 public @interface WithSize {

src/main/java/com/code_intelligence/jazzer/mutation/mutator/collection/ChunkCrossOvers.java

@@ -22,9 +22,11 @@
 import java.util.Collection;
 import java.util.Iterator;
 import java.util.LinkedHashMap;
+import java.util.LinkedHashSet;
 import java.util.List;
 import java.util.Map;
 import java.util.Map.Entry;
+import java.util.Set;
 
 final class ChunkCrossOvers {
   private ChunkCrossOvers() {}
@@ -98,6 +100,25 @@ static <K, V> void insertChunk(
     }
   }
 
+  static <K> void insertChunk(
+      Set<K> set, Set<K> otherSet, int maxSize, PseudoRandom prng, boolean hasFixedSize) {
+    int originalSize = set.size();
+    int maxChunkSize = Math.min(maxSize - originalSize, otherSet.size());
+    int chunkSize = prng.sizeInClosedRange(1, maxChunkSize, hasFixedSize);
+    int fromChunkOffset = prng.closedRange(0, otherSet.size() - chunkSize);
+    Iterator<K> fromIterator = otherSet.iterator();
+    for (int i = 0; i < fromChunkOffset; i++) {
+      fromIterator.next();
+    }
+    // insertChunk only inserts new entries and does not overwrite existing
+    // ones. As skipping those entries would lead to fewer insertions than
+    // requested, loop over the rest of the set to fill the chunk if possible.
+    while (set.size() < originalSize + chunkSize && fromIterator.hasNext()) {
+      K key = fromIterator.next();
+      set.add(key);
+    }
+  }
+
   static <K, V> void overwriteChunk(
       Map<K, V> map, Map<K, V> otherMap, PseudoRandom prng, boolean hasFixedSize) {
     onCorrespondingChunks(
@@ -117,6 +138,24 @@ static <K, V> void overwriteChunk(
         hasFixedSize);
   }
 
+  static <E> void overwriteChunk(
+      Set<E> set, Set<E> otherSet, PseudoRandom prng, boolean hasFixedSize) {
+    onCorrespondingChunks(
+        set,
+        otherSet,
+        prng,
+        (fromIterator, toIterator, chunkSize) -> {
+          Set<E> elementsToAdd = new LinkedHashSet<>(chunkSize);
+          for (int i = 0; i < chunkSize; i++) {
+            toIterator.next();
+            toIterator.remove();
+            elementsToAdd.add(fromIterator.next());
+          }
+          set.addAll(elementsToAdd);
+        },
+        hasFixedSize);
+  }
+
   static <K, V> void crossOverChunk(
       Map<K, V> map,
       Map<K, V> otherMap,
@@ -130,6 +169,23 @@ static <K, V> void crossOverChunk(
     }
   }
 
+  static <E> void crossOverChunk(
+      Set<E> set, Set<E> otherSet, SerializingMutator<E> mutator, PseudoRandom prng) {
+    onCorrespondingChunks(
+        set,
+        otherSet,
+        prng,
+        (fromIterator, toIterator, chunkSize) -> {
+          Set<E> elementsToAdd = new LinkedHashSet<>(chunkSize);
+          for (int i = 0; i < chunkSize; i++) {
+            elementsToAdd.add(mutator.crossOver(toIterator.next(), fromIterator.next(), prng));
+            toIterator.remove();
+          }
+          set.addAll(elementsToAdd);
+        },
+        mutator.hasFixedSize());
+  }
+
   private static <K, V> void crossOverChunkKeys(
       Map<K, V> map, Map<K, V> otherMap, SerializingMutator<K> keyMutator, PseudoRandom prng) {
     onCorrespondingChunks(
@@ -198,6 +254,11 @@ private interface ChunkMapOperation<K, V> {
     void apply(Iterator<Entry<K, V>> fromIterator, Iterator<Entry<K, V>> toIterator, int chunkSize);
   }
 
+  @FunctionalInterface
+  private interface ChunkSetOperation<E> {
+    void apply(Iterator<E> fromIterator, Iterator<E> toIterator, int chunkSize);
+  }
+
   static <K, V> void onCorrespondingChunks(
       Map<K, V> map,
       Map<K, V> otherMap,
@@ -219,6 +280,32 @@ static <K, V> void onCorrespondingChunks(
     operation.apply(fromIterator, toIterator, chunkSize);
   }
 
+  static <K> void onCorrespondingChunks(
+      Set<K> set,
+      Set<K> otherSet,
+      PseudoRandom prng,
+      ChunkSetOperation<K> operation,
+      boolean hasFixedSize) {
+
+    if (set.isEmpty() || otherSet.isEmpty()) {
+      return;
+    }
+
+    int maxChunkSize = Math.min(set.size(), otherSet.size());
+    int chunkSize = prng.sizeInClosedRange(1, maxChunkSize, hasFixedSize);
+    int fromChunkOffset = prng.closedRange(0, otherSet.size() - chunkSize);
+    int toChunkOffset = prng.closedRange(0, set.size() - chunkSize);
+    Iterator<K> fromIterator = otherSet.iterator();
+    for (int i = 0; i < fromChunkOffset; i++) {
+      fromIterator.next();
+    }
+    Iterator<K> toIterator = set.iterator();
+    for (int i = 0; i < toChunkOffset; i++) {
+      toIterator.next();
+    }
+    operation.apply(fromIterator, toIterator, chunkSize);
+  }
+
   public enum CrossOverAction {
     INSERT_CHUNK,
     OVERWRITE_CHUNK,

src/main/java/com/code_intelligence/jazzer/mutation/mutator/collection/ChunkMutations.java

@@ -16,10 +16,11 @@
 
 package com.code_intelligence.jazzer.mutation.mutator.collection;
 
+import static com.code_intelligence.jazzer.mutation.support.Preconditions.require;
+
 import com.code_intelligence.jazzer.mutation.api.PseudoRandom;
 import com.code_intelligence.jazzer.mutation.api.SerializingMutator;
 import com.code_intelligence.jazzer.mutation.api.ValueMutator;
-import com.code_intelligence.jazzer.mutation.support.Preconditions;
 import java.util.AbstractList;
 import java.util.ArrayDeque;
 import java.util.ArrayList;
@@ -162,6 +163,52 @@ static <K, V, KW, VW> boolean mutateRandomKeysChunk(
     return grownBy > 0;
   }
 
+  static <E> boolean mutateRandomChunk(
+      Set<E> set, SerializingMutator<E> elementMutator, PseudoRandom prng) {
+    int originalSize = set.size();
+    require(originalSize > 0, "mutateRandomSetChunk requires set size > 0");
+    int chunkSize = prng.sizeInClosedRange(1, originalSize, elementMutator.hasFixedSize());
+    int chunkOffset = prng.closedRange(0, originalSize - chunkSize);
+
+    Iterator<E> iterator = set.iterator();
+
+    // Skip to chunk offset
+    for (int i = 0; i < chunkOffset; i++) {
+      iterator.next();
+    }
+
+    // Collect elements to mutate and remove
+    List<E> originalElements = new ArrayList<>(chunkSize);
+    List<E> elementsToMutate = new ArrayList<>(chunkSize);
+    for (int i = 0; i < chunkSize; i++) {
+      E element = iterator.next();
+      originalElements.add(element);
+      elementsToMutate.add(elementMutator.detach(element));
+    }
+
+    // Try mutating each chunk element into a yet-not-present element in the set.
+    // Abort after MAX_FAILED_INSERTION_ATTEMPTS failed mutations in total.
+    int successCount = 0;
+    int failedAttemptsCount = 0;
+    for (E element : elementsToMutate) {
+      while (failedAttemptsCount < MAX_FAILED_INSERTION_ATTEMPTS) {
+        // Each element keeps getting mutated until we get a completely novel element.
+        element = elementMutator.mutate(element, prng);
+        if (set.add(element)) {
+          successCount++;
+          break;
+        } else {
+          failedAttemptsCount++;
+        }
+      }
+    }
+
+    for (int i = 0; i < successCount; i++) {
+      set.remove(originalElements.get(i));
+    }
+    return successCount > 0;
+  }
+
   public static <K, V> void mutateRandomValuesChunk(
       Map<K, V> map, ValueMutator<V> valueMutator, PseudoRandom prng) {
     Collection<Map.Entry<K, V>> collection = map.entrySet();
@@ -182,7 +229,7 @@ public static <K, V> void mutateRandomValuesChunk(
   static <T> boolean growBy(
       Set<T> set, Consumer<T> addIfNew, int delta, Supplier<T> candidateSupplier) {
     int oldSize = set.size();
-    Preconditions.require(delta >= 0);
+    require(delta >= 0);
 
     final int targetSize = oldSize + delta;
     int remainingAttempts = MAX_FAILED_INSERTION_ATTEMPTS;

src/main/java/com/code_intelligence/jazzer/mutation/mutator/collection/CollectionMutators.java

@@ -23,6 +23,10 @@ public final class CollectionMutators {
   private CollectionMutators() {}
 
   public static Stream<MutatorFactory> newFactories() {
-    return Stream.of(new ListMutatorFactory(), new MapMutatorFactory(), new ArrayMutatorFactory());
+    return Stream.of(
+        new ListMutatorFactory(),
+        new MapMutatorFactory(),
+        new SetMutatorFactory(),
+        new ArrayMutatorFactory());
   }
 }