org.sonar.java.checks.JunitMethodDeclarationCheck.java Source code

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Here is the source code for org.sonar.java.checks.JunitMethodDeclarationCheck.java

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/*
 * SonarQube Java
 * Copyright (C) 2012-2017 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 GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 3 of the License, or (at your option) any later version.
 *
 * 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 GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License
 * along with this program; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
 */
package org.sonar.java.checks;

import com.google.common.annotations.VisibleForTesting;
import com.google.common.collect.ImmutableList;
import org.apache.commons.lang.StringUtils;
import org.sonar.check.Rule;
import org.sonar.plugins.java.api.IssuableSubscriptionVisitor;
import org.sonar.plugins.java.api.semantic.Symbol;
import org.sonar.plugins.java.api.tree.ClassTree;
import org.sonar.plugins.java.api.tree.MethodTree;
import org.sonar.plugins.java.api.tree.Tree;
import org.sonar.plugins.java.api.tree.TypeTree;

import java.util.List;

@Rule(key = "S2391")
public class JunitMethodDeclarationCheck extends IssuableSubscriptionVisitor {

    private static final String JUNIT_SETUP = "setUp";
    private static final String JUNIT_TEARDOWN = "tearDown";
    private static final String JUNIT_SUITE = "suite";
    private static final int MAX_STRING_DISTANCE = 3;

    @Override
    public List<Tree.Kind> nodesToVisit() {
        return ImmutableList.of(Tree.Kind.CLASS);
    }

    @Override
    public void visitNode(Tree tree) {
        if (isJunit3Class((ClassTree) tree)) {
            for (Tree member : ((ClassTree) tree).members()) {
                if (member.is(Tree.Kind.METHOD)) {
                    visitMethod((MethodTree) member);
                }
            }
        }
    }

    private void visitMethod(MethodTree methodTree) {
        String name = methodTree.simpleName().name();
        TypeTree returnType = methodTree.returnType();
        if (JUNIT_SETUP.equals(name) || JUNIT_TEARDOWN.equals(name)) {
            checkSetupTearDownSignature(methodTree);
        } else if (JUNIT_SUITE.equals(name)) {
            checkSuiteSignature(methodTree);
        } else if ((returnType != null && returnType.symbolType().isSubtypeOf("junit.framework.Test"))
                || areVerySimilarStrings(JUNIT_SUITE, name)) {
            addIssueForMethodBadName(methodTree, JUNIT_SUITE, name);
        } else if (areVerySimilarStrings(JUNIT_SETUP, name)) {
            addIssueForMethodBadName(methodTree, JUNIT_SETUP, name);
        } else if (areVerySimilarStrings(JUNIT_TEARDOWN, name)) {
            addIssueForMethodBadName(methodTree, JUNIT_TEARDOWN, name);
        }
    }

    @VisibleForTesting
    protected boolean areVerySimilarStrings(String expected, String actual) {
        // cut complexity when the strings length difference is bigger than the accepted threshold
        return (Math.abs(expected.length() - actual.length()) <= MAX_STRING_DISTANCE)
                && StringUtils.getLevenshteinDistance(expected, actual) < MAX_STRING_DISTANCE;
    }

    private void checkSuiteSignature(MethodTree methodTree) {
        Symbol.MethodSymbol symbol = methodTree.symbol();
        if (!symbol.isPublic()) {
            reportIssue(methodTree, "Make this method \"public\".");
        } else if (!symbol.isStatic()) {
            reportIssue(methodTree, "Make this method \"static\".");
        } else if (!methodTree.parameters().isEmpty()) {
            reportIssue(methodTree, "This method does not accept parameters.");
        } else {
            TypeTree returnType = methodTree.returnType();
            if (returnType != null && !returnType.symbolType().isSubtypeOf("junit.framework.Test")) {
                reportIssue(methodTree,
                        "This method should return either a \"junit.framework.Test\" or a \"junit.framework.TestSuite\".");
            }
        }
    }

    private void checkSetupTearDownSignature(MethodTree methodTree) {
        Symbol.MethodSymbol symbol = methodTree.symbol();
        if (!symbol.isPublic() && !symbol.isProtected()) {
            reportIssue(methodTree, "Make this method \"public\".");
        } else if (!methodTree.parameters().isEmpty()) {
            reportIssue(methodTree, "This method does not accept parameters.");
        } else {
            TypeTree returnType = methodTree.returnType();
            if (returnType != null && !returnType.symbolType().isVoid()) {
                reportIssue(methodTree, "Make this method return \"void\".");
            }
        }
    }

    private void addIssueForMethodBadName(MethodTree methodTree, String expected, String actual) {
        reportIssue(methodTree, "This method should be named \"" + expected + "\" not \"" + actual + "\".");
    }

    private void reportIssue(MethodTree methodTree, String message) {
        reportIssue(methodTree.simpleName(), message);
    }

    private static boolean isJunit3Class(ClassTree classTree) {
        return classTree.symbol().type().isSubtypeOf("junit.framework.TestCase");
    }

}