APIDifferenceStrategy.java

/*
 *  Copyright (c) 2001-2024, Jean Tessier
 *  All rights reserved.
 *  
 *  Redistribution and use in source and binary forms, with or without
 *  modification, are permitted provided that the following conditions
 *  are met:
 *  
 *      * Redistributions of source code must retain the above copyright
 *        notice, this list of conditions and the following disclaimer.
 *  
 *      * Redistributions in binary form must reproduce the above copyright
 *        notice, this list of conditions and the following disclaimer in the
 *        documentation and/or other materials provided with the distribution.
 *  
 *      * Neither the name of Jean Tessier nor the names of his contributors
 *        may be used to endorse or promote products derived from this software
 *        without specific prior written permission.
 *  
 *  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 *  "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 *  LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 *  A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR
 *  CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
 *  EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
 *  PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
 *  PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
 *  LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
 *  NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 *  SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

package com.jeantessier.diff;

import java.util.*;
import java.util.stream.Stream;

import com.jeantessier.classreader.*;

public class APIDifferenceStrategy extends DifferenceStrategyDecorator {
    public APIDifferenceStrategy(DifferenceStrategy delegate) {
        super(delegate);
    }

    public boolean isClassDifferent(Classfile oldClass, Classfile newClass) {
        return isRemoved(oldClass, newClass) ||
               isNew(oldClass, newClass) ||
               isClassModified(oldClass, newClass);
    }

    protected boolean isClassModified(Classfile oldClass, Classfile newClass) {
        return isDeclarationModified(oldClass, newClass) ||
               isDeprecationModified(oldClass, newClass) ||
               checkForDifferentFeatures(oldClass, newClass);
    }

    public boolean isDeclarationModified(Classfile oldClass, Classfile newClass) {
        return !oldClass.getDeclaration().equals(newClass.getDeclaration());
    }

    private boolean checkForDifferentFeatures(Classfile oldClass, Classfile newClass) {
        return checkForDifferentFields(oldClass, newClass) ||
               checkForDifferentMethods(oldClass, newClass);
    }

    private boolean checkForDifferentFields(Classfile oldClass, Classfile newClass) {
        return Stream.concat(
                oldClass.getAllFields().stream(),
                newClass.getAllFields().stream())
                .map(Feature_info::getName)
                .distinct()
                .anyMatch(name -> isFieldDifferent(
                        oldClass.getField(field -> field.getName().equals(name)),
                        newClass.getField(field -> field.getName().equals(name))));
    }

    private boolean checkForDifferentMethods(Classfile oldClass, Classfile newClass) {
        return Stream.concat(
                oldClass.getAllMethods().stream(),
                newClass.getAllMethods().stream())
                .map(Feature_info::getSignature)
                .distinct()
                .anyMatch(signature -> isMethodDifferent(
                        oldClass.getMethod(method -> method.getSignature().equals(signature)),
                        newClass.getMethod(method -> method.getSignature().equals(signature))));
    }

    public boolean isFieldDifferent(Field_info oldField, Field_info newField) {
        return isRemoved(oldField, newField) ||
               isNew(oldField, newField) ||
               isDeprecationModified(oldField, newField) ||
               isDeclarationModified(oldField, newField) ||
               isConstantValueDifferent(oldField.getConstantValue(), newField.getConstantValue());
    }

    public boolean isMethodDifferent(Method_info oldMethod, Method_info newMethod) {
        return isRemoved(oldMethod, newMethod) ||
               isNew(oldMethod, newMethod) ||
               isDeprecationModified(oldMethod, newMethod) ||
               isDeclarationModified(oldMethod, newMethod) ||
               isCodeDifferent(oldMethod.getCode(), newMethod.getCode());
    }

    protected boolean isRemoved(Object oldElement, Object newElement) {
        return oldElement != null && newElement == null;
    }

    protected boolean isDeprecationModified(Deprecatable oldItem, Deprecatable newItem) {
        return oldItem.isDeprecated() != newItem.isDeprecated();
    }

    private boolean isDeclarationModified(Feature_info oldFeature, Feature_info newFeature) {
        return !oldFeature.getDeclaration().equals(newFeature.getDeclaration());
    }

    protected boolean isNew(Object oldElement, Object newElement) {
        return oldElement == null && newElement != null;
    }

    public boolean isPackageDifferent(Map<String, Classfile> oldPackage, Map<String, Classfile> newPackage) {
        return isPackageRemoved(oldPackage, newPackage) ||
               isPackageNew(oldPackage, newPackage) ||
               isPackageModified(oldPackage, newPackage);
    }

    protected boolean isPackageRemoved(Map<String, Classfile> oldPackage, Map<String, Classfile> newPackage) {
        return !oldPackage.isEmpty() && newPackage.isEmpty();
    }

    protected boolean isPackageNew(Map<String, Classfile> oldPackage, Map<String, Classfile> newPackage) {
        return oldPackage.isEmpty() && !newPackage.isEmpty();
    }

    protected boolean isPackageModified(Map<String, Classfile> oldPackage, Map<String, Classfile> newPackage) {
        return oldPackage.size() != newPackage.size() ||
               checkForDifferentClasses(oldPackage, newPackage);
    }

    private boolean checkForDifferentClasses(Map<String, Classfile> oldPackage, Map<String, Classfile> newPackage) {
        return Stream.concat(
                oldPackage.keySet().stream(),
                newPackage.keySet().stream())
                .distinct()
                .anyMatch(name -> isClassDifferent(oldPackage.get(name), newPackage.get(name)));
    }
}