IG: report more cases of object construction inside equals() and hashCode() methods

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

@@ -2157,6 +2157,7 @@ synchronization.on.get.class.display.name=Synchronization on 'getClass()'
 synchronization.on.get.class.problem.descriptor=Synchronization on <code>#ref()</code> #loc
 object.instantiation.inside.equals.or.hashcode.display.name=Object instantiation inside 'equals()' or 'hashCode()'
 object.instantiation.inside.equals.or.hashcode.problem.descriptor=Object instantiation inside ''{0}()'' #loc
+object.instantiation.inside.equals.or.hashcode.problem.descriptor2=Object instantiation inside ''{0}()'' ({1})#loc
 lambda.body.can.be.code.block.name=Lambda body can be code block
 lambda.body.can.be.code.block.quickfix=Expand lambda body to {...}
 lambda.parameter.type.can.be.specified.name=Lambda parameter type can be specified

plugins/InspectionGadgets/src/com/siyeh/ig/performance/ObjectInstantiationInEqualsHashCodeInspection.java

@@ -42,6 +42,9 @@ public class ObjectInstantiationInEqualsHashCodeInspection extends BaseInspectio
   protected String buildErrorString(Object... infos) {
     final PsiMethod method = PsiTreeUtil.getParentOfType((PsiElement)infos[0], PsiMethod.class);
     assert method != null;
+    if (infos.length > 1) {
+      return InspectionGadgetsBundle.message("object.instantiation.inside.equals.or.hashcode.problem.descriptor2", method.getName(), infos[1]);
+    }
     return InspectionGadgetsBundle.message("object.instantiation.inside.equals.or.hashcode.problem.descriptor", method.getName());
   }
 
@@ -50,9 +53,68 @@ public class ObjectInstantiationInEqualsHashCodeInspection extends BaseInspectio
     return new ObjectInstantiationInEqualsHashCodeVisitor();
   }
 
-  // todo check boxing too
   private static class ObjectInstantiationInEqualsHashCodeVisitor extends BaseInspectionVisitor {
 
+    @Override
+    public void visitExpression(PsiExpression expression) {
+      if (!ExpressionUtils.isAutoBoxed(expression)) {
+        return;
+      }
+      registerError(expression, expression, "autoboxing");
+    }
+
+    @Override
+    public void visitForeachStatement(PsiForeachStatement statement) {
+      final PsiExpression iteratedValue = statement.getIteratedValue();
+      if (iteratedValue == null || iteratedValue.getType() instanceof PsiArrayType) {
+        return;
+      }
+      registerError(iteratedValue, iteratedValue, "iterator");
+    }
+
+    @Override
+    public void visitMethodCallExpression(PsiMethodCallExpression expression) {
+      final PsiReferenceExpression methodExpression = expression.getMethodExpression();
+      final PsiMethod method = expression.resolveMethod();
+      if (method == null) {
+        return;
+      }
+      if (method.isVarArgs()) {
+        registerError(expression, expression, "varargs call");
+      }
+      else {
+        final String name = methodExpression.getReferenceName();
+        if (!"valueOf".equals(name)) {
+          return;
+        }
+        final PsiExpressionList argumentList = expression.getArgumentList();
+        final PsiExpression[] expressions = argumentList.getExpressions();
+        if (expressions.length != 1) {
+          return;
+        }
+        final PsiClass aClass = method.getContainingClass();
+        if (aClass == null) {
+          return;
+        }
+        final String qualifiedName = aClass.getQualifiedName();
+        if (!CommonClassNames.JAVA_LANG_SHORT.equals(qualifiedName) && !CommonClassNames.JAVA_LANG_INTEGER.equals(qualifiedName) &&
+            !CommonClassNames.JAVA_LANG_LONG.equals(qualifiedName) && !CommonClassNames.JAVA_LANG_DOUBLE.equals(qualifiedName) &&
+            !CommonClassNames.JAVA_LANG_FLOAT.equals(qualifiedName) && !CommonClassNames.JAVA_LANG_CHARACTER.equals(qualifiedName)) {
+          return;
+        }
+        registerError(expression, expression);
+      }
+    }
+
+    @Override
+    public void visitArrayInitializerExpression(PsiArrayInitializerExpression expression) {
+      if (!(expression.getParent() instanceof PsiVariable)) {
+        // new expressions are already reported.
+        return;
+      }
+      registerError(expression, expression);
+    }
+
     @Override
     public void visitPolyadicExpression(PsiPolyadicExpression expression) {
       super.visitPolyadicExpression(expression);

plugins/InspectionGadgets/src/inspectionDescriptions/ObjectInstantiationInEqualsHashCode.html

@@ -2,7 +2,8 @@
 <body>
 Reports construction of (temporary) new objects inside an <b>equals()</b>, <b>hashCode()</b>, <b>compareTo</b> or
 <b>Comparator.compare()</b> method.
-This can cause significant performance problems when for example objects of classes with such constructs are added to a <b>Set</b> or <b>Map</b>,
+Besides constructor invocations, new objects can also be created by autoboxing or iterator creation inside a foreach statement.
+This can cause performance problems for example when objects are added to a <b>Set</b> or <b>Map</b>,
 where these methods will be called often.
 This inspection will not warn when the objects are created in a <b>throw</b> or <b>assert</b> statement.
 <!-- tooltip end -->

plugins/InspectionGadgets/test/com/siyeh/igtest/performance/object_instantiation_in_equals_hash_code/ObjectInstantiationInEqualsHashCode.java

@@ -8,7 +8,7 @@ class ObjectInstantiationInEqualsHashCode {
 
   public boolean equals(Object o) {
     ObjectInstantiationInEqualsHashCode other = (ObjectInstantiationInEqualsHashCode)o;
-    return Arrays.equals(new <warning descr="Object instantiation inside 'equals()'">Object</warning>[] {a, b}, new <warning descr="Object instantiation inside 'equals()'">Object</warning>[] {other.a, other.b});
+    return Arrays.equals(new <warning descr="Object instantiation inside 'equals()'">Object</warning>[] {a, <warning descr="Object instantiation inside 'equals()' (autoboxing)">b</warning>}, new <warning descr="Object instantiation inside 'equals()'">Object</warning>[] {other.a, <warning descr="Object instantiation inside 'equals()' (autoboxing)">other.b</warning>});
   }
 
   public int hashCode() {
@@ -38,4 +38,31 @@ class X implements Comparable<X>, Comparator<String> {
     new <warning descr="Object instantiation inside 'compare()'">Object</warning>();
     return 0;
   }
+}
+class Y {
+
+  public java.util.List<Object> fooList = new java.util.ArrayList<>();
+
+  @Override
+  public int hashCode() {
+    Integer i = <warning descr="Object instantiation inside 'hashCode()' (autoboxing)">1</warning>;
+    <warning descr="Object instantiation inside 'hashCode()'">Short.valueOf((short) 1)</warning>;
+    Byte.valueOf((byte) 1); // nope
+    <warning descr="Object instantiation inside 'hashCode()'">Long.valueOf(1)</warning>;
+    Boolean.valueOf(true); // nope
+    <warning descr="Object instantiation inside 'hashCode()'">Character.valueOf('a')</warning>;
+    <warning descr="Object instantiation inside 'hashCode()'">Float.valueOf((float) 1.0)</warning>;
+    <warning descr="Object instantiation inside 'hashCode()'">Double.valueOf(1.0)</warning>;
+    <warning descr="Object instantiation inside 'hashCode()' (autoboxing)">i</warning>++;
+    int j = 1;
+    j++;
+    int[] is = <warning descr="Object instantiation inside 'hashCode()'">{j}</warning>;
+    int hashCode = 7;
+    <warning descr="Object instantiation inside 'hashCode()' (varargs call)">java.util.Arrays.asList()</warning>;
+    for (Object fooElement : <warning descr="Object instantiation inside 'hashCode()' (iterator)">fooList</warning>) {
+      hashCode = 31 * hashCode + (fooElement == null ? 0 : fooElement.hashCode());
+    }
+    return hashCode;
+  }
+
 }