/*
* Copyright 2003-2014 Dave Griffith, Bas Leijdekkers
*
* 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.siyeh.ig.equality;
import com.intellij.codeInspection.ProblemDescriptor;
import com.intellij.openapi.project.Project;
import com.intellij.psi.*;
import com.intellij.psi.tree.IElementType;
import com.intellij.psi.util.PsiTreeUtil;
import com.intellij.psi.util.PsiUtil;
import com.intellij.psi.util.TypeConversionUtil;
import com.siyeh.InspectionGadgetsBundle;
import com.siyeh.ig.BaseInspection;
import com.siyeh.ig.BaseInspectionVisitor;
import com.siyeh.ig.InspectionGadgetsFix;
import com.siyeh.ig.PsiReplacementUtil;
import com.siyeh.ig.psiutils.ClassUtils;
import com.siyeh.ig.psiutils.ParenthesesUtils;
import org.jetbrains.annotations.Nls;
import org.jetbrains.annotations.NonNls;
import org.jetbrains.annotations.NotNull;
import org.jetbrains.annotations.Nullable;
public class EqualityOperatorComparesObjectsInspection extends BaseInspection {
@Nls
@NotNull
@Override
public String getDisplayName() {
return InspectionGadgetsBundle.message("equality.operator.compares.objects.name");
}
@NotNull
@Override
protected String buildErrorString(Object... infos) {
return InspectionGadgetsBundle.message("equality.operator.compares.objects.descriptor", infos);
}
@Override
public BaseInspectionVisitor buildVisitor() {
return new ObjectEqualityVisitor();
}
@NotNull
@Override
protected InspectionGadgetsFix[] buildFixes(Object... infos) {
return new InspectionGadgetsFix[]{new EqualsFix(infos), new SafeEqualsFix(infos)};
}
private static void doFixImpl(@NotNull PsiElement element) {
final PsiBinaryExpression exp = (PsiBinaryExpression)element;
final PsiExpression lhs = exp.getLOperand();
final PsiExpression rhs = exp.getROperand();
if (rhs == null) {
return;
}
final PsiExpression strippedLhs = ParenthesesUtils.stripParentheses(lhs);
if (strippedLhs == null) {
return;
}
final PsiExpression strippedRhs = ParenthesesUtils.stripParentheses(rhs);
if (strippedRhs == null) {
return;
}
final String lhText = strippedLhs.getText();
final String rhText = strippedRhs.getText();
final String prefix = exp.getOperationTokenType().equals(JavaTokenType.EQEQ) ? "" : "!";
@NonNls final String expString;
if (ParenthesesUtils.getPrecedence(strippedLhs) > ParenthesesUtils.METHOD_CALL_PRECEDENCE) {
expString = prefix + '(' + lhText + ").equals(" + rhText + ')';
}
else {
expString = prefix + lhText + ".equals(" + rhText + ')';
}
PsiReplacementUtil.replaceExpression(exp, expString);
}
private static void doSafeFixImpl(PsiElement element) {
final PsiBinaryExpression exp = (PsiBinaryExpression)element;
final PsiExpression lhs = exp.getLOperand();
final PsiExpression rhs = exp.getROperand();
if (rhs == null) {
return;
}
final PsiExpression strippedLhs =
ParenthesesUtils.stripParentheses(lhs);
if (strippedLhs == null) {
return;
}
final PsiExpression strippedRhs =
ParenthesesUtils.stripParentheses(rhs);
if (strippedRhs == null) {
return;
}
final String lhsText = strippedLhs.getText();
final String rhsText = strippedRhs.getText();
final PsiJavaToken operationSign = exp.getOperationSign();
final IElementType tokenType = operationSign.getTokenType();
final String signText = operationSign.getText();
@NonNls final StringBuilder newExpression = new StringBuilder();
if (PsiUtil.isLanguageLevel7OrHigher(element) && ClassUtils.findClass("java.util.Objects", element) != null) {
if (tokenType.equals(JavaTokenType.NE)) {
newExpression.append('!');
}
newExpression.append("java.util.Objects.equals(").append(lhsText).append(',').append(rhsText).append(')');
}
else {
newExpression.append(lhsText).append("==null?").append(rhsText).append(signText).append(" null:");
if (tokenType.equals(JavaTokenType.NE)) {
newExpression.append('!');
}
if (ParenthesesUtils.getPrecedence(strippedLhs) > ParenthesesUtils.METHOD_CALL_PRECEDENCE) {
newExpression.append('(').append(lhsText).append(')');
}
else {
newExpression.append(lhsText);
}
newExpression.append(".equals(").append(rhsText).append(')');
}
PsiReplacementUtil.replaceExpressionAndShorten(exp, newExpression.toString());
}
private static class SafeEqualsFix extends InspectionGadgetsFix {
private final Object[] myInfos;
public SafeEqualsFix(Object... infos) {
myInfos = infos;
}
@Nls
@NotNull
@Override
public String getName() {
return InspectionGadgetsBundle.message("equality.operator.compares.objects.safe.quickfix", myInfos);
}
@Nls
@NotNull
@Override
public String getFamilyName() {
return InspectionGadgetsBundle.message("equality.operator.compares.objects.safe.family.quickfix");
}
@Override
protected void doFix(Project project, ProblemDescriptor descriptor) {
doSafeFixImpl(descriptor.getPsiElement());
}
}
private static class EqualsFix extends InspectionGadgetsFix {
private final Object[] myInfos;
public EqualsFix(Object... infos) {
myInfos = infos;
}
@Nls
@NotNull
@Override
public String getName() {
return InspectionGadgetsBundle.message("equality.operator.compares.objects.quickfix", myInfos);
}
@Nls
@NotNull
@Override
public String getFamilyName() {
return InspectionGadgetsBundle.message("equality.operator.compares.objects.family.quickfix");
}
@Override
protected void doFix(Project project, ProblemDescriptor descriptor) {
doFixImpl(descriptor.getPsiElement());
}
}
private static class ObjectEqualityVisitor extends BaseInspectionVisitor {
@Override
public void visitBinaryExpression(PsiBinaryExpression expression) {
super.visitBinaryExpression(expression);
final IElementType tokenType = expression.getOperationTokenType();
if (!tokenType.equals(JavaTokenType.NE) &&
!tokenType.equals(JavaTokenType.EQEQ)) {
return;
}
final PsiExpression lhs = expression.getLOperand();
final PsiType lhsType = lhs.getType();
if (lhsType == null || lhsType instanceof PsiPrimitiveType || TypeConversionUtil.isEnumType(lhsType)) {
return;
}
final PsiExpression rhs = expression.getROperand();
if (rhs == null) {
return;
}
final PsiType rhsType = rhs.getType();
if (rhsType == null || rhsType instanceof PsiPrimitiveType || TypeConversionUtil.isEnumType(rhsType)) {
return;
}
if (lhs instanceof PsiThisExpression || rhs instanceof PsiThisExpression) {
final PsiMethod method = PsiTreeUtil.getParentOfType(expression, PsiMethod.class);
if (method != null && "equals".equals(method.getName()) && method.getParameterList().getParametersCount() == 1) {
final PsiClass containingClass = method.getContainingClass();
if (isThisQualifier(lhs, containingClass) || isThisQualifier(rhs, containingClass)) {
return;
}
}
}
final String operationText = expression.getOperationSign().getText();
final String prefix = tokenType.equals(JavaTokenType.NE) ? "!" : "";
registerError(expression, operationText, prefix);
}
private static boolean isThisQualifier(@Nullable PsiExpression expression, @Nullable PsiClass psiClass) {
if (expression instanceof PsiThisExpression) {
final PsiJavaCodeReferenceElement qualifier = ((PsiThisExpression)expression).getQualifier();
return qualifier == null || psiClass != null && qualifier.isReferenceTo(psiClass);
}
return false;
}
}
}