Add ReflectionRemapper#withClassNamePreprocessor

src/main/java/xyz/jpenilla/reflectionremapper/ClassNamePreprocessingReflectionRemapper.java

@@ -0,0 +1,51 @@
+/*
+ * reflection-remapper
+ *
+ * Copyright (c) 2021-2023 Jason Penilla
+ *
+ * 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 xyz.jpenilla.reflectionremapper;
+
+import java.util.function.UnaryOperator;
+import org.checkerframework.checker.nullness.qual.NonNull;
+import org.checkerframework.framework.qual.DefaultQualifier;
+
+@DefaultQualifier(NonNull.class)
+final class ClassNamePreprocessingReflectionRemapper implements ReflectionRemapper {
+  private final ReflectionRemapper delegate;
+  private final UnaryOperator<String> processor;
+
+  ClassNamePreprocessingReflectionRemapper(
+    final ReflectionRemapper delegate,
+    final UnaryOperator<String> processor
+  ) {
+    this.delegate = delegate;
+    this.processor = processor;
+  }
+
+  @Override
+  public String remapClassName(final String className) {
+    return this.delegate.remapClassName(this.processor.apply(className));
+  }
+
+  @Override
+  public String remapFieldName(final Class<?> holdingClass, final String fieldName) {
+    return this.delegate.remapFieldName(holdingClass, fieldName);
+  }
+
+  @Override
+  public String remapMethodName(final Class<?> holdingClass, final String methodName, final Class<?>... paramTypes) {
+    return this.delegate.remapMethodName(holdingClass, methodName, paramTypes);
+  }
+}

src/main/java/xyz/jpenilla/reflectionremapper/ReflectionRemapper.java

@@ -27,6 +27,7 @@
 import java.util.ArrayList;
 import java.util.Collections;
 import java.util.Objects;
+import java.util.function.UnaryOperator;
 import net.fabricmc.mappingio.MappingReader;
 import net.fabricmc.mappingio.tree.MemoryMappingTree;
 import org.checkerframework.checker.nullness.qual.NonNull;
@@ -108,6 +109,19 @@ default String remapClassOrArrayName(final String name) {
     return this.remapClassName(name);
   }
 
+  /**
+   * Creates a new reflection remapper that processes class names using the provided
+   * operator before remapping them with this remapper.
+   *
+   * <p>This may be useful when class names must be mangled to avoid relocation.</p>
+   *
+   * @param preprocessor class name preprocessor
+   * @return delegating reflection remapper
+   */
+  default ReflectionRemapper withClassNamePreprocessor(final UnaryOperator<String> preprocessor) {
+    return new ClassNamePreprocessingReflectionRemapper(this, preprocessor);
+  }
+
   /**
    * Returns a noop {@link ReflectionRemapper} instance which simply passes through the given
    * names without remapping.