LiteralAsArgToStringEqualsInspection.java

/*
 * Copyright 2003-2007 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.style;

import com.intellij.codeInspection.ProblemDescriptor;
import com.intellij.openapi.project.Project;
import com.intellij.psi.*;
import com.intellij.util.IncorrectOperationException;
import com.siyeh.HardcodedMethodConstants;
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.ParenthesesUtils;
import com.siyeh.ig.psiutils.TypeUtils;
import org.jetbrains.annotations.NonNls;
import org.jetbrains.annotations.NotNull;

public class LiteralAsArgToStringEqualsInspection
  extends BaseInspection {

  @Override
  @NotNull
  public String getDisplayName() {
    return InspectionGadgetsBundle.message(
      "literal.as.arg.to.string.equals.display.name");
  }

  @Override
  @NotNull
  public String buildErrorString(Object... infos) {
    final String methodName = (String)infos[0];
    return InspectionGadgetsBundle.message(
      "literal.as.arg.to.string.equals.problem.descriptor",
      methodName);
  }

  @Override
  public BaseInspectionVisitor buildVisitor() {
    return new LiteralAsArgToEqualsVisitor();
  }

  @Override
  public InspectionGadgetsFix buildFix(Object... infos) {
    return new SwapEqualsFix();
  }

  private static class SwapEqualsFix extends InspectionGadgetsFix {

    @Override
    @NotNull
    public String getFamilyName() {
      return InspectionGadgetsBundle.message(
        "literal.as.arg.to.string.equals.flip.quickfix");
    }

    @Override
    public void doFix(Project project, ProblemDescriptor descriptor)
      throws IncorrectOperationException {
      final PsiExpression argument =
        (PsiExpression)descriptor.getPsiElement();
      final PsiElement argumentList = argument.getParent();
      final PsiMethodCallExpression expression =
        (PsiMethodCallExpression)argumentList.getParent();
      final PsiReferenceExpression methodExpression =
        expression.getMethodExpression();
      final PsiExpression target =
        methodExpression.getQualifierExpression();
      final String methodName = methodExpression.getReferenceName();
      final PsiExpression strippedTarget =
        ParenthesesUtils.stripParentheses(target);
      if (strippedTarget == null) {
        return;
      }
      final PsiExpression strippedArg =
        ParenthesesUtils.stripParentheses(argument);
      if (strippedArg == null) {
        return;
      }
      final String callString;
      if (ParenthesesUtils.getPrecedence(strippedArg) >
          ParenthesesUtils.METHOD_CALL_PRECEDENCE) {
        callString = '(' + strippedArg.getText() + ")." + methodName +
                     '(' + strippedTarget.getText() + ')';
      }
      else {
        callString = strippedArg.getText() + '.' + methodName + '(' +
                     strippedTarget.getText() + ')';
      }
      PsiReplacementUtil.replaceExpression(expression, callString);
    }
  }

  private static class LiteralAsArgToEqualsVisitor
    extends BaseInspectionVisitor {

    @Override
    public void visitMethodCallExpression(
      @NotNull PsiMethodCallExpression expression) {
      super.visitMethodCallExpression(expression);
      final PsiReferenceExpression methodExpression =
        expression.getMethodExpression();
      @NonNls final String methodName =
        methodExpression.getReferenceName();
      if (!HardcodedMethodConstants.EQUALS.equals(methodName) &&
          !HardcodedMethodConstants.EQUALS_IGNORE_CASE.equals(
            methodName)) {
        return;
      }
      final PsiExpressionList argList = expression.getArgumentList();
      final PsiExpression[] args = argList.getExpressions();
      if (args.length != 1) {
        return;
      }
      final PsiExpression argument = args[0];
      final PsiType argumentType = argument.getType();
      if (argumentType == null) {
        return;
      }
      if (!(argument instanceof PsiLiteralExpression)) {
        return;
      }
      if (!TypeUtils.isJavaLangString(argumentType)) {
        return;
      }
      final PsiExpression target =
        methodExpression.getQualifierExpression();
      if (target instanceof PsiLiteralExpression) {
        return;
      }
      registerError(argument, methodName);
    }
  }
}