IDEA-67522 (array equals inspection misses == operator on two arrays)

Added "Array comparison using '==', instead of 'Arrays.equals()'" inspection

plugins/InspectionGadgets/src/com/siyeh/InspectionGadgetsBundle.properties

@@ -1867,3 +1867,6 @@ html.tag.can.be.javadoc.tag.quickfix=Replace with '{@code ...}'
 try.finally.can.be.try.with.resources.display.name='try finally' replaceable with 'try' with resources
 try.finally.can.be.try.with.resources.problem.descriptor=<code>#ref</code> can use automatic resource management
 try.finally.can.be.try.with.resources.quickfix=Replace with 'try' with resources
+array.comparison.display.name=Array comparison using '==', instead of 'Arrays.equals()'
+array.comparison.problem.descriptor=Array objects are compared using <code>#ref</code>, not 'Arrays.equals()' #loc
+array.comparison.quickfix=Replace with 'Arrays.equals()'

plugins/InspectionGadgets/src/com/siyeh/ig/InspectionGadgetsPlugin.java

@@ -516,6 +516,7 @@ public class InspectionGadgetsPlugin implements ApplicationComponent,
 
     private void registerBugInspections() {
         m_inspectionClasses.add(ArchaicSystemPropertyAccessInspection.class);
+        m_inspectionClasses.add(ArrayEqualityInspection.class);
         m_inspectionClasses.add(ArrayEqualsInspection.class);
         m_inspectionClasses.add(AssertWithSideEffectsInspection.class);
         m_inspectionClasses.add(ConstantAssertConditionInspection.class);

plugins/InspectionGadgets/src/com/siyeh/ig/bugs/ArrayEqualityInspection.java

@@ -0,0 +1,131 @@
+/*
+ * Copyright 2003-2011 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.bugs;
+
+import com.intellij.codeInspection.ProblemDescriptor;
+import com.intellij.openapi.project.Project;
+import com.intellij.psi.*;
+import com.intellij.psi.tree.IElementType;
+import com.intellij.util.IncorrectOperationException;
+import com.siyeh.InspectionGadgetsBundle;
+import com.siyeh.ig.BaseInspection;
+import com.siyeh.ig.BaseInspectionVisitor;
+import com.siyeh.ig.InspectionGadgetsFix;
+import com.siyeh.ig.psiutils.ComparisonUtils;
+import org.jetbrains.annotations.NonNls;
+import org.jetbrains.annotations.NotNull;
+
+public class ArrayEqualityInspection extends BaseInspection {
+
+    @Override
+    @NotNull
+    public String getDisplayName() {
+        return InspectionGadgetsBundle.message(
+                "array.comparison.display.name");
+    }
+
+    @Override
+    @NotNull
+    public String buildErrorString(Object... infos) {
+        return InspectionGadgetsBundle.message(
+                "array.comparison.problem.descriptor");
+    }
+
+    @Override
+    public InspectionGadgetsFix buildFix(Object... infos) {
+        return new ArrayEqualityFix();
+    }
+
+    private static class ArrayEqualityFix extends InspectionGadgetsFix {
+        
+        @NotNull
+        @Override
+        public String getName() {
+            return InspectionGadgetsBundle.message("array.comparison.quickfix");
+        }
+
+        @Override
+        protected void doFix(Project project, ProblemDescriptor descriptor)
+                throws IncorrectOperationException {
+            final PsiElement element = descriptor.getPsiElement();
+            final PsiElement parent = element.getParent();
+            if (!(parent instanceof PsiBinaryExpression)) {
+                return;
+            }
+            final PsiBinaryExpression binaryExpression =
+                    (PsiBinaryExpression) parent;
+            final IElementType tokenType =
+                    binaryExpression.getOperationTokenType();
+            @NonNls final StringBuilder newExpressionText = new StringBuilder();
+            if (JavaTokenType.NE.equals(tokenType)) {
+                newExpressionText.append('!');
+            } else if (!JavaTokenType.EQEQ.equals(tokenType)) {
+                return;
+            }
+            newExpressionText.append("java.util.Arrays.equals(");
+            newExpressionText.append(binaryExpression.getLOperand().getText());
+            newExpressionText.append(',');
+            final PsiExpression rhs = binaryExpression.getROperand();
+            if (rhs == null) {
+                return;
+            }
+            newExpressionText.append(rhs.getText());
+            newExpressionText.append(')');
+            replaceExpressionAndShorten(binaryExpression,
+                    newExpressionText.toString());
+        }
+    }
+
+    @Override
+    public BaseInspectionVisitor buildVisitor() {
+        return new ArrayEqualityVisitor();
+    }
+
+    private static class ArrayEqualityVisitor extends BaseInspectionVisitor {
+
+        @Override public void visitBinaryExpression(
+                @NotNull PsiBinaryExpression expression) {
+            super.visitBinaryExpression(expression);
+            if(!(expression.getROperand() != null)){
+                return;
+            }
+            if (!ComparisonUtils.isEqualityComparison(expression)) {
+                return;
+            }
+            final PsiExpression lhs = expression.getLOperand();
+            if (!(lhs.getType() instanceof PsiArrayType)) {
+                return;
+            }
+            final PsiExpression rhs = expression.getROperand();
+            if (rhs == null) {
+                return;
+            }
+            if (!(rhs.getType() instanceof PsiArrayType)) {
+                return;
+            }
+            final String lhsText = lhs.getText();
+            if (PsiKeyword.NULL.equals(lhsText)) {
+                return;
+            }
+            final String rhsText = rhs.getText();
+            if (PsiKeyword.NULL.equals(rhsText)) {
+                return;
+            }
+            final PsiJavaToken sign = expression.getOperationSign();
+            registerError(sign);
+        }
+    }
+}

plugins/InspectionGadgets/src/com/siyeh/ig/bugs/NumberEqualityInspection.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2003-2010 Dave Griffith, Bas Leijdekkers
+ * Copyright 2003-2011 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.
@@ -48,7 +48,7 @@ public class NumberEqualityInspection extends BaseInspection {
 
     @Override
     public BaseInspectionVisitor buildVisitor() {
-        return new ObjectEqualityVisitor();
+        return new NumberEqualityVisitor();
     }
 
     @Override
@@ -56,7 +56,7 @@ public class NumberEqualityInspection extends BaseInspection {
         return new EqualityToEqualsFix();
     }
 
-    private static class ObjectEqualityVisitor extends BaseInspectionVisitor {
+    private static class NumberEqualityVisitor extends BaseInspectionVisitor {
 
         @Override public void visitBinaryExpression(
                 @NotNull PsiBinaryExpression expression) {
@@ -90,8 +90,8 @@ public class NumberEqualityInspection extends BaseInspection {
             registerError(sign);
         }
 
-        private static boolean hasNumberType(PsiExpression lhs) {
-            return TypeUtils.expressionHasTypeOrSubtype(lhs,
+        private static boolean hasNumberType(PsiExpression expression) {
+            return TypeUtils.expressionHasTypeOrSubtype(expression,
                     CommonClassNames.JAVA_LANG_NUMBER);
         }
     }

plugins/InspectionGadgets/src/inspectionDescriptions/ArrayEquality.html

@@ -0,0 +1,8 @@
+<html>
+<body>
+This inspection reports any use of <b>==</b> to test for Array equality,
+rather than the <b>"java.util.Arrays.equals()"</b> method.
+<p>
+<small>New in 10.5, Powered by InspectionGadgets</small>
+</body>
+</html>