1 files changed, 46 insertions, 0 deletions
diff --git a/src/main/java/com/code_intelligence/jazzer/mutation/api/Debuggable.java b/src/main/java/com/code_intelligence/jazzer/mutation/api/Debuggable.java
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+++ b/src/main/java/com/code_intelligence/jazzer/mutation/api/Debuggable.java
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+/*
+ * 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.api;
+
+import static java.util.Collections.newSetFromMap;
+import static java.util.Objects.requireNonNull;
+
+import java.util.IdentityHashMap;
+import java.util.Set;
+import java.util.function.Predicate;
+
+public interface Debuggable {
+  /**
+   * Returns a string representation of the object that is meant to be used to make assertions about
+   * its structure in tests.
+   *
+   * @param isInCycle evaluates to {@code true} if a cycle has been detected during recursive calls
+   *                  of this function. Must be called at most once with {@code this} as the single
+   *                  argument. Implementing classes that know that their current instance can never
+   *                  be contained in recursive substructures need not call this method.
+   */
+  String toDebugString(Predicate<Debuggable> isInCycle);
+
+  /**
+   * Returns a string representation of the given {@link Debuggable} that is meant to be used to
+   * make assertions about its structure in tests.
+   */
+  static String getDebugString(Debuggable debuggable) {
+    Set<Debuggable> seen = newSetFromMap(new IdentityHashMap<>());
+    return debuggable.toDebugString(child -> !seen.add(requireNonNull(child)));
+  }
+}