IDEA-94922 (Report negatively named boolean variables and suggest to perform 'Invert Boolean' for them)

plugins/InspectionGadgets/InspectionGadgetsAnalysis/src/META-INF/InspectionGadgets.xml

@@ -760,6 +760,10 @@
     <localInspection language="JAVA" shortName="LawOfDemeter" bundle="com.siyeh.InspectionGadgetsBundle" key="law.of.demeter.display.name"
                      groupBundle="messages.InspectionsBundle" groupKey="group.names.data.flow.issues" enabledByDefault="false"
                      level="WARNING" implementationClass="com.siyeh.ig.dataflow.LawOfDemeterInspection"/>
+    <localInspection language="JAVA" shortName="NegativelyNamedBooleanVariable" bundle="com.siyeh.InspectionGadgetsBundle"
+                     key="negatively.named.boolean.variable.display.name" groupBundle="messages.InspectionsBundle"
+                     groupKey="group.names.data.flow.issues" enabledByDefault="false" level="WARNING"
+                     implementationClass="com.siyeh.ig.dataflow.NegativelyNamedBooleanVariableInspection"/>
     <localInspection language="JAVA" shortName="OrredNotEqualExpression" bundle="com.siyeh.InspectionGadgetsBundle"
                      key="orred.not.equal.expression.display.name" groupBundle="messages.InspectionsBundle"
                      groupKey="group.names.data.flow.issues" enabledByDefault="true" level="WARNING"

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

@@ -2059,6 +2059,8 @@ problematic.whitespace.spaces.problem.descriptor=File ''{0}'' uses spaces for in
 problematic.whitespace.show.whitespaces.quickfix=Toggle show whitespace in the editor
 problematic.varargs.method.display.name=Non-varargs method overrides varargs method
 problematic.varargs.method.override.problem.descriptor=Non-varargs method <code>#ref()</code> overrides varargs method #loc
+negatively.named.boolean.variable.problem.descriptor=Boolean variable <code>#ref</code> is negatively named #loc
+negatively.named.boolean.variable.display.name=Negatively named boolean variable
 invert.quickfix.family.name=Invert boolean
 invert.method.quickfix=Invert method
 invert.quickfix=Invert ''{0}''

plugins/InspectionGadgets/InspectionGadgetsAnalysis/src/com/siyeh/ig/dataflow/NegativelyNamedBooleanVariableInspectionBase.java

@@ -0,0 +1,72 @@
+/*
+ * Copyright 2000-2013 JetBrains s.r.o.
+ *
+ * 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.dataflow;
+
+import com.intellij.psi.PsiType;
+import com.intellij.psi.PsiVariable;
+import com.siyeh.InspectionGadgetsBundle;
+import com.siyeh.ig.BaseInspection;
+import com.siyeh.ig.BaseInspectionVisitor;
+import org.jetbrains.annotations.Nls;
+import org.jetbrains.annotations.NonNls;
+import org.jetbrains.annotations.NotNull;
+
+/**
+ * @author Bas Leijdekkers
+ */
+public class NegativelyNamedBooleanVariableInspectionBase extends BaseInspection {
+
+  @NonNls
+  private static final String[] NEGATIVE_NAMES = {"not", "isNot", "shouldNot", "shallNot", "willNot", "cannot", "cant", "hasNot",
+    "couldNot", "hidden", "isHidden", "disabled", "isDisabled"};
+
+  @Nls
+  @NotNull
+  @Override
+  public String getDisplayName() {
+    return InspectionGadgetsBundle.message("negatively.named.boolean.variable.display.name");
+  }
+
+  @NotNull
+  @Override
+  protected String buildErrorString(Object... infos) {
+    return InspectionGadgetsBundle.message("negatively.named.boolean.variable.problem.descriptor");
+  }
+
+  @Override
+  public BaseInspectionVisitor buildVisitor() {
+    return new NegativelyNamedBooleanVariableVisitor();
+  }
+
+  private static class NegativelyNamedBooleanVariableVisitor extends BaseInspectionVisitor {
+
+    @Override
+    public void visitVariable(PsiVariable variable) {
+      super.visitVariable(variable);
+      if (!PsiType.BOOLEAN.equals(variable.getType())) {
+        return;
+      }
+      final String name = variable.getName();
+      for (final String negativeName : NEGATIVE_NAMES) {
+        if (name.startsWith(negativeName) &&
+            (name.length() == negativeName.length() || Character.isUpperCase(name.charAt(negativeName.length())))) {
+          registerVariableError(variable, variable);
+          break;
+        }
+      }
+    }
+  }
+}

plugins/InspectionGadgets/src/com/siyeh/ig/dataflow/NegativelyNamedBooleanVariableInspection.java

@@ -0,0 +1,35 @@
+/*
+ * Copyright 2000-2013 JetBrains s.r.o.
+ *
+ * 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.dataflow;
+
+import com.intellij.psi.PsiVariable;
+import com.siyeh.InspectionGadgetsBundle;
+import com.siyeh.ig.InspectionGadgetsFix;
+import com.siyeh.ig.fixes.InvertBooleanFix;
+import org.jetbrains.annotations.Nullable;
+
+/**
+ * @author Bas Leijdekkers
+ */
+public class NegativelyNamedBooleanVariableInspection extends NegativelyNamedBooleanVariableInspectionBase {
+
+  @Nullable
+  @Override
+  protected InspectionGadgetsFix buildFix(Object... infos) {
+    final PsiVariable variable = (PsiVariable)infos[0];
+    return new InvertBooleanFix(InspectionGadgetsBundle.message("invert.quickfix", variable.getName()));
+  }
+}

plugins/InspectionGadgets/src/inspectionDescriptions/NegativelyNamedBooleanVariable.html

@@ -0,0 +1,9 @@
+<html>
+<body>
+Reports negatively named variables, for example 'disabled', 'hidden', 'isNotChanged'.
+It is usually more clear to invert the <b>boolean</b> value and remove the negation from the name.
+<!-- tooltip end -->
+<p>
+<small>New in 13</small>
+</body>
+</html>

plugins/InspectionGadgets/testsrc/com/siyeh/ig/dataflow/NegativelyNamedBooleanVariableInspectionTest.java

@@ -0,0 +1,38 @@
+/*
+ * Copyright 2000-2013 JetBrains s.r.o.
+ *
+ * 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.dataflow;
+
+import com.intellij.codeInspection.InspectionProfileEntry;
+import com.siyeh.ig.LightInspectionTestCase;
+
+/**
+ * @author Bas Leijdekkers
+ */
+public class NegativelyNamedBooleanVariableInspectionTest extends LightInspectionTestCase {
+
+  public void testTree() {
+    doTest("class X {" +
+           "  boolean /*Boolean variable 'hidden' is negatively named*/hidden/**/ = false;" +
+           "  boolean /*Boolean variable 'disabled' is negatively named*/disabled/**/ = false;" +
+           "  boolean /*Boolean variable 'isNotChanged' is negatively named*/isNotChanged/**/ = false;" +
+           "}");
+  }
+
+  @Override
+  protected InspectionProfileEntry getInspection() {
+    return new NegativelyNamedBooleanVariableInspection();
+  }
+}