org.sonar.java.checks.design.ClassCouplingCheck Maven / Gradle / Ivy

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/*
 * SonarQube Java
 * Copyright (C) 2012-2024 SonarSource SA
 * mailto:info AT sonarsource DOT com
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the Sonar Source-Available License Version 1, as published by SonarSource SA.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
 * See the Sonar Source-Available License for more details.
 *
 * You should have received a copy of the Sonar Source-Available License
 * along with this program; if not, see https://sonarsource.com/license/ssal/
 */
package org.sonar.java.checks.design;

import java.util.HashSet;
import java.util.Set;
import javax.annotation.Nullable;
import org.sonar.check.Rule;
import org.sonar.check.RuleProperty;
import org.sonar.java.checks.helpers.ExpressionsHelper;
import org.sonar.plugins.java.api.tree.ClassTree;
import org.sonar.plugins.java.api.tree.IdentifierTree;
import org.sonar.plugins.java.api.tree.MemberSelectExpressionTree;
import org.sonar.plugins.java.api.tree.Tree;

@Rule(key = "S1200")
public class ClassCouplingCheck extends AbstractCouplingChecker {

  private static final int DEFAULT_MAX = 20;

  @RuleProperty(
    key = "max",
    description = "Maximum number of classes a single class is allowed to depend upon",
    defaultValue = "" + DEFAULT_MAX)
  public int max = DEFAULT_MAX;

  @Override
  public void visitClass(ClassTree tree) {
    if (tree.is(Tree.Kind.CLASS) && tree.simpleName() != null) {
      nesting.push(types);
      types = new HashSet<>();
    }
    checkTypes(tree.superClass(), types);
    checkTypes(tree.superInterfaces());
    super.visitClass(tree);
    if (tree.is(Tree.Kind.CLASS) && tree.simpleName() != null) {
      if (types.size() > max) {
        context.reportIssue(
          this,
          tree.simpleName(),
          "Split this class into smaller and more specialized ones to reduce its dependencies on other classes from " +
            types.size() + " to the maximum authorized " + max + " or less.");
      }
      types = nesting.pop();
    }
  }

  @Override
  public void checkTypes(@Nullable Tree type, @Nullable Set types) {
    if (type == null || types == null) {
      return;
    }
    if (type.is(Tree.Kind.IDENTIFIER)) {
      types.add(((IdentifierTree) type).name());
    } else if (type.is(Tree.Kind.MEMBER_SELECT)) {
      MemberSelectExpressionTree mse = (MemberSelectExpressionTree) type;
      String concatenated = ExpressionsHelper.concatenate(mse);
      types.add(concatenated);
    }
  }
}