feat: support generic classes in ConstructorBasedBeanMutator

Author: simonresch

src/main/java/com/code_intelligence/jazzer/mutation/mutator/aggregate/CachedConstructorMutatorFactory.java

@@ -18,6 +18,7 @@
 
 import static com.code_intelligence.jazzer.mutation.mutator.aggregate.AggregatesHelper.asInstantiationFunction;
 import static com.code_intelligence.jazzer.mutation.mutator.aggregate.BeanSupport.findConstructorsByParameterCount;
+import static com.code_intelligence.jazzer.mutation.mutator.aggregate.BeanSupport.resolveAnnotatedParameterTypes;
 import static com.code_intelligence.jazzer.mutation.support.StreamSupport.findFirstPresent;
 import static com.code_intelligence.jazzer.mutation.support.TypeSupport.asSubclassOrEmpty;
 
@@ -63,7 +64,7 @@ private static Optional<SerializingMutator<?>> buildMutator(
     return AggregatesHelper.createMutator(
         factory,
         constructor.getDeclaringClass(),
-        constructor.getAnnotatedParameterTypes(),
+        resolveAnnotatedParameterTypes(constructor, initialType),
         fromParametersToObject,
         fromObjectToParameters,
         initialType,

src/test/java/com/code_intelligence/jazzer/mutation/mutator/StressTest.java

@@ -492,6 +492,27 @@ public String toString() {
     }
   }
 
+  public static class GenericOnlyConstructorBean<T> {
+    private final T t;
+
+    GenericOnlyConstructorBean(T t) {
+      this.t = t;
+    }
+
+    @Override
+    public boolean equals(Object o) {
+      if (this == o) return true;
+      if (o == null || getClass() != o.getClass()) return false;
+      GenericOnlyConstructorBean<T> that = (GenericOnlyConstructorBean<T>) o;
+      return Objects.equals(t, that.t);
+    }
+
+    @Override
+    public int hashCode() {
+      return Objects.hash(t);
+    }
+  }
+
   public static class SuperBuilderTarget {
     private final String foo;
 
@@ -971,6 +992,12 @@ void singleParam(int parameter) {}
             false,
             manyDistinctElements(),
             manyDistinctElements()),
+        arguments(
+            new TypeHolder<@NotNull GenericOnlyConstructorBean<String>>() {}.annotatedType(),
+            "[Nullable<String>] -> GenericOnlyConstructorBean",
+            false,
+            manyDistinctElements(),
+            manyDistinctElements()),
         arguments(
             new TypeHolder<@NotNull List<OnlyConstructorBean>>() {}.annotatedType(),
             "List<Nullable<[Nullable<String>, Nullable<List<Nullable<Integer>>>, Boolean] ->"

src/test/java/com/code_intelligence/jazzer/mutation/mutator/aggregate/CachedConstructorMutatorTest.java

@@ -192,4 +192,34 @@ void testEmptyArgsConstructor() throws IOException {
     EmptyArgs read = mutator.readExclusive(new ByteArrayInputStream(new byte[] {}));
     mutator.writeExclusive(read, new ByteArrayOutputStream());
   }
+
+  static class GenericClass<T> {
+    private final T t;
+
+    GenericClass(T t) {
+      this.t = t;
+    }
+
+    @Override
+    public boolean equals(Object o) {
+      if (this == o) return true;
+      if (o == null || getClass() != o.getClass()) return false;
+      GenericClass<T> that = (GenericClass<T>) o;
+      return Objects.equals(t, that.t);
+    }
+
+    @Override
+    public int hashCode() {
+      return Objects.hash(t);
+    }
+  }
+
+  @Test
+  void testGenericClass() {
+    SerializingMutator<GenericClass<String>> mutator =
+        (SerializingMutator<GenericClass<String>>)
+            Mutators.newFactory()
+                .createOrThrow(new TypeHolder<GenericClass<String>>() {}.annotatedType());
+    assertThat(mutator.toString()).startsWith("Nullable<[Nullable<String>] -> GenericClass>");
+  }
 }