IG: fix some "Instantiating object to get Class object" inspection issues (IDEA-141554)

java/testFramework/src/com/siyeh/ig/LightInspectionTestCase.java

@@ -116,6 +116,9 @@ public abstract class LightInspectionTestCase extends LightCodeInsightFixtureTes
       else if (text.startsWith("!")) {
         newText.append("<error descr=\"").append(text.substring(1)).append("\">");
       }
+      else if (text.startsWith(" ")) {
+        newText.append("/*").append(text).append("*/");
+      }
       else {
         newText.append("<warning descr=\"").append(text).append("\">");
       }

plugins/InspectionGadgets/InspectionGadgetsAnalysis/src/com/siyeh/ig/performance/InstantiatingObjectToGetClassObjectInspection.java

@@ -18,6 +18,7 @@ package com.siyeh.ig.performance;
 import com.intellij.codeInspection.ProblemDescriptor;
 import com.intellij.openapi.project.Project;
 import com.intellij.psi.*;
+import com.intellij.psi.util.PsiUtil;
 import com.siyeh.InspectionGadgetsBundle;
 import com.siyeh.ig.BaseInspection;
 import com.siyeh.ig.BaseInspectionVisitor;
@@ -51,6 +52,10 @@ public class InstantiatingObjectToGetClassObjectInspection
 
   @Override
   protected InspectionGadgetsFix buildFix(Object... infos) {
+    final PsiMethodCallExpression methodCallExpression = (PsiMethodCallExpression)infos[0];
+    if (methodCallExpression.getParent() instanceof PsiExpressionStatement) {
+      return null;
+    }
     return new InstantiatingObjectToGetClassObjectFix();
   }
 
@@ -66,12 +71,9 @@ public class InstantiatingObjectToGetClassObjectInspection
 
     @Override
     public void doFix(Project project, ProblemDescriptor descriptor) {
-      final PsiMethodCallExpression expression =
-        (PsiMethodCallExpression)descriptor.getPsiElement();
-      final PsiReferenceExpression methodExpression =
-        expression.getMethodExpression();
-      final PsiExpression qualifier =
-        methodExpression.getQualifierExpression();
+      final PsiMethodCallExpression expression = (PsiMethodCallExpression)descriptor.getPsiElement();
+      final PsiReferenceExpression methodExpression = expression.getMethodExpression();
+      final PsiExpression qualifier = methodExpression.getQualifierExpression();
       if (qualifier == null) {
         return;
       }
@@ -79,21 +81,30 @@ public class InstantiatingObjectToGetClassObjectInspection
       if (type == null) {
         return;
       }
-      PsiReplacementUtil.replaceExpression(expression,
-                                           getTypeText(type, new StringBuilder()) + ".class", new CommentTracker());
+      PsiReplacementUtil.replaceExpression(expression, getTypeText(type, new StringBuilder()) + ".class", new CommentTracker());
     }
 
-    private static StringBuilder getTypeText(PsiType type,
-                                             StringBuilder text) {
+    private static StringBuilder getTypeText(PsiType type, StringBuilder text) {
       if (type instanceof PsiArrayType) {
         text.append("[]");
         final PsiArrayType arrayType = (PsiArrayType)type;
         getTypeText(arrayType.getComponentType(), text);
       }
       else if (type instanceof PsiClassType) {
-        final String canonicalText = type.getCanonicalText();
-        final String typeText = PsiNameHelper.getQualifiedClassName(canonicalText, false);
-        text.insert(0, typeText);
+        PsiClass aClass = ((PsiClassType)type).resolve();
+        if (aClass != null && PsiUtil.isLocalClass(aClass)) {
+          text.insert(0, aClass.getName());
+          aClass = aClass.getContainingClass();
+          while (aClass != null) {
+            text.insert(0, aClass.getName() + '.');
+            aClass = aClass.getContainingClass();
+          }
+        }
+        else {
+          final String canonicalText = type.getCanonicalText();
+          final String typeText = PsiNameHelper.getQualifiedClassName(canonicalText, false);
+          text.insert(0, typeText);
+        }
       }
       else {
         text.insert(0, type.getCanonicalText());
@@ -111,18 +122,14 @@ public class InstantiatingObjectToGetClassObjectInspection
     extends BaseInspectionVisitor {
 
     @Override
-    public void visitMethodCallExpression(
-      @NotNull PsiMethodCallExpression expression) {
+    public void visitMethodCallExpression(@NotNull PsiMethodCallExpression expression) {
       super.visitMethodCallExpression(expression);
-      final PsiReferenceExpression methodExpression =
-        expression.getMethodExpression();
-      @NonNls final String methodName =
-        methodExpression.getReferenceName();
+      final PsiReferenceExpression methodExpression = expression.getMethodExpression();
+      @NonNls final String methodName = methodExpression.getReferenceName();
       if (!"getClass".equals(methodName) || !expression.getArgumentList().isEmpty()) {
         return;
       }
-      final PsiExpression qualifier =
-        methodExpression.getQualifierExpression();
+      final PsiExpression qualifier = PsiUtil.skipParenthesizedExprDown(methodExpression.getQualifierExpression());
       if (!(qualifier instanceof PsiNewExpression)) {
         return;
       }
@@ -130,7 +137,7 @@ public class InstantiatingObjectToGetClassObjectInspection
       if (newExpression.getAnonymousClass() != null) {
         return;
       }
-      registerError(expression);
+      registerError(expression, expression);
     }
   }
 }

plugins/InspectionGadgets/testsrc/com/siyeh/ig/performance/InstantiatingObjectToGetClassObjectInspectionTest.java

@@ -0,0 +1,90 @@
+// Copyright 2000-2018 JetBrains s.r.o. Use of this source code is governed by the Apache 2.0 license that can be found in the LICENSE file.
+package com.siyeh.ig.performance;
+
+import com.intellij.codeInspection.InspectionProfileEntry;
+import com.siyeh.InspectionGadgetsBundle;
+import com.siyeh.ig.LightInspectionTestCase;
+import org.jetbrains.annotations.Nullable;
+
+/**
+ * @author Bas Leijdekkers
+ */
+@SuppressWarnings("ALL")
+public class InstantiatingObjectToGetClassObjectInspectionTest extends LightInspectionTestCase {
+
+  public void testComplicated() {
+    doTest("import java.util.*;" +
+           "class X {" +
+           "  void m() {" +
+           "    Class<? extends ArrayList> aClass = /*Instantiating object to get Class object*/(new ArrayList</* 1*/String>())/*_*/./* 2*/getClass()/**/;" +
+           "  }" +
+           "}");
+    checkQuickFix(InspectionGadgetsBundle.message("instantiating.object.to.get.class.object.replace.quickfix"),
+                  "import java.util.*;" +
+                  "class X {" +
+                  "  void m() {" +
+                  "    /* 1*/" +
+                  "    /* 2*/ Class<? extends ArrayList> aClass = ArrayList.class;" +
+                  "  }" +
+                  "}");
+  }
+
+  public void testTopLevelExpresion() {
+    doTest("class X {" +
+           "  void m() {" +
+           "    /*Instantiating object to get Class object*/new /*_*/String().getClass()/**/;" +
+           "  }" +
+           "}");
+    assertQuickFixNotAvailable(InspectionGadgetsBundle.message("instantiating.object.to.get.class.object.replace.quickfix"));
+  }
+
+  public void testAnonymousClass() {
+    doTest("class X {" +
+           "  void m() {" +
+           "    new Object() {}.getClass();" +
+           "  }" +
+           "}");
+  }
+
+  public void testArray() {
+    doTest("class X {" +
+           "  void m() {" +
+           "    Class<? extends String[]> aClass = /*Instantiating object to get Class object*/new String[]/*_*/ {}.getClass()/**/;" +
+           "  }" +
+           "}");
+    checkQuickFix(InspectionGadgetsBundle.message("instantiating.object.to.get.class.object.replace.quickfix"),
+                  "class X {" +
+                  "  void m() {" +
+                  "    Class<? extends String[]> aClass = String[].class;" +
+                  "  }" +
+                  "}");
+  }
+
+  public void testLocalClasses() {
+    doTest("class X {" +
+           "  void m() {" +
+           "    class A {" +
+           "      class B {" +
+           "      }" +
+           "    }" +
+           "    Class<?> clazz = /*Instantiating object to get Class object*/new A()/*_*/.new B().getClass()/**/;" +
+           "  }" +
+           "}");
+    checkQuickFix(InspectionGadgetsBundle.message("instantiating.object.to.get.class.object.replace.quickfix"),
+                  "class X {" +
+                  "  void m() {" +
+                  "    class A {" +
+                  "      class B {" +
+                  "      }" +
+                  "    }" +
+                  "    Class<?> clazz = A.B.class;" +
+                  "  }" +
+                  "}");
+  }
+
+  @Nullable
+  @Override
+  protected InspectionProfileEntry getInspection() {
+    return new InstantiatingObjectToGetClassObjectInspection();
+  }
+}