Quick fix for unused symbol inspection.

idea/src/org/jetbrains/kotlin/idea/inspections/UnusedSymbolInspection.kt

@@ -52,6 +52,12 @@ import org.jetbrains.kotlin.idea.search.usagesSearch.dataClassComponentFunctionN
 import org.jetbrains.kotlin.psi.JetTypeParameter
 import org.jetbrains.kotlin.idea.search.usagesSearch.DefaultSearchHelper
 import com.intellij.util.Processor
+import com.intellij.codeInspection.LocalQuickFix
+import com.intellij.openapi.project.Project
+import com.intellij.codeInspection.ProblemDescriptor
+import com.intellij.codeInsight.daemon.QuickFixBundle
+import com.intellij.codeInsight.FileModificationService
+import com.intellij.refactoring.safeDelete.SafeDeleteHandler
 
 public class UnusedSymbolInspection : AbstractKotlinInspection() {
     private val javaInspection = UnusedDeclarationInspection()
@@ -60,6 +66,19 @@ public class UnusedSymbolInspection : AbstractKotlinInspection() {
 
     override fun buildVisitor(holder: ProblemsHolder, isOnTheFly: Boolean, session: LocalInspectionToolSession): PsiElementVisitor {
         return object : JetVisitorVoid() {
+            private fun createQuickFix(declaration: JetNamedDeclaration): LocalQuickFix {
+                return object : LocalQuickFix {
+                    override fun getName() = QuickFixBundle.message("safe.delete.text", declaration.getName())
+
+                    override fun getFamilyName() = "whatever"
+
+                    override fun applyFix(project: Project, descriptor: ProblemDescriptor?) {
+                        if (!FileModificationService.getInstance().prepareFileForWrite(declaration.getContainingFile())) return
+                        SafeDeleteHandler.invoke(project, array(declaration), false)
+                    }
+                }
+            }
+
             override fun visitClass(klass: JetClass) {
                 if (klass.getName() == null) return
 
@@ -72,8 +91,9 @@ public class UnusedSymbolInspection : AbstractKotlinInspection() {
                 holder.registerProblem(
                         klass.getNameIdentifier(),
                         JetBundle.message("unused.class", klass.getName()),
-                        ProblemHighlightType.LIKE_UNUSED_SYMBOL
+                        ProblemHighlightType.LIKE_UNUSED_SYMBOL,
-                ) // TODO add quick fix to delete it
+                        createQuickFix(klass)
+                )
             }
 
             override fun visitNamedFunction(function: JetNamedFunction) {
@@ -87,8 +107,9 @@ public class UnusedSymbolInspection : AbstractKotlinInspection() {
                 holder.registerProblem(
                         function.getNameIdentifier(),
                         JetBundle.message("unused.function", function.getName()),
-                        ProblemHighlightType.LIKE_UNUSED_SYMBOL
+                        ProblemHighlightType.LIKE_UNUSED_SYMBOL,
-                ) // TODO add quick fix to delete it
+                        createQuickFix(function)
+                )
             }
 
             override fun visitProperty(property: JetProperty) {
@@ -102,8 +123,9 @@ public class UnusedSymbolInspection : AbstractKotlinInspection() {
                 holder.registerProblem(
                         property.getNameIdentifier(),
                         JetBundle.message("unused.property", property.getName()),
-                        ProblemHighlightType.LIKE_UNUSED_SYMBOL
+                        ProblemHighlightType.LIKE_UNUSED_SYMBOL,
-                ) // TODO add quick fix to delete it
+                        createQuickFix(property)
+                )
             }
 
             override fun visitParameter(parameter: JetParameter) {
@@ -120,8 +142,9 @@ public class UnusedSymbolInspection : AbstractKotlinInspection() {
                 holder.registerProblem(
                         parameter.getNameIdentifier(),
                         JetBundle.message("unused.property", parameter.getName()),
-                        ProblemHighlightType.LIKE_UNUSED_SYMBOL
+                        ProblemHighlightType.LIKE_UNUSED_SYMBOL,
-                ) // TODO add quick fix to delete it
+                        createQuickFix(parameter)
+                )
             }
 
             override fun visitTypeParameter(parameter: JetTypeParameter) {
@@ -132,8 +155,9 @@ public class UnusedSymbolInspection : AbstractKotlinInspection() {
                 holder.registerProblem(
                         parameter.getNameIdentifier(),
                         JetBundle.message("unused.type.parameter", parameter.getName()),
-                        ProblemHighlightType.LIKE_UNUSED_SYMBOL
+                        ProblemHighlightType.LIKE_UNUSED_SYMBOL,
-                ) // TODO add quick fix to delete it
+                        createQuickFix(parameter)
+                )
             }
         }
     }
@@ -200,4 +224,4 @@ public class UnusedSymbolInspection : AbstractKotlinInspection() {
 
         return !query.forEach(Processor { declaration.isAncestor(it.getElement()) })
     }
-}
+}

idea/testData/quickfix/removeUnused/.inspection

@@ -0,0 +1 @@
+org.jetbrains.kotlin.idea.inspections.UnusedSymbolInspection

idea/testData/quickfix/removeUnused/afterUnusedClass.kt

@@ -0,0 +1,3 @@
+// "Safe delete 'UnusedClass'" "true"
+class DummyClass
+

idea/testData/quickfix/removeUnused/afterUnusedFunction.kt

@@ -0,0 +1,4 @@
+// "Safe delete 'unusedFun'" "true"
+fun dummy() {
+}
+

idea/testData/quickfix/removeUnused/afterUnusedProperty.kt

@@ -0,0 +1,3 @@
+// "Safe delete 'property'" "true"
+class UnusedProperty() {
+}

idea/testData/quickfix/removeUnused/afterUnusedPropertyAsConstructorParameter.kt

@@ -0,0 +1,2 @@
+// "Safe delete 'property'" "true"
+class UnusedPropertyAsConstructorParameter()

idea/testData/quickfix/removeUnused/afterUnusedTypeParameter.kt

@@ -0,0 +1,2 @@
+// "Safe delete 'T'" "true"
+class UnusedTypeParameter<P>(val p: P)

idea/testData/quickfix/removeUnused/beforeUnusedClass.kt

@@ -0,0 +1,4 @@
+// "Safe delete 'UnusedClass'" "true"
+class DummyClass
+
+class <caret>UnusedClass

idea/testData/quickfix/removeUnused/beforeUnusedFunction.kt

@@ -0,0 +1,7 @@
+// "Safe delete 'unusedFun'" "true"
+fun dummy() {
+}
+
+fun <caret>unusedFun() {
+
+}

idea/testData/quickfix/removeUnused/beforeUnusedProperty.kt

@@ -0,0 +1,4 @@
+// "Safe delete 'property'" "true"
+class UnusedProperty() {
+    val <caret>property: String = ":)"
+}

idea/testData/quickfix/removeUnused/beforeUnusedPropertyAsConstructorParameter.kt

@@ -0,0 +1,2 @@
+// "Safe delete 'property'" "true"
+class UnusedPropertyAsConstructorParameter(val <caret>property: String)

idea/testData/quickfix/removeUnused/beforeUnusedTypeParameter.kt

@@ -0,0 +1,2 @@
+// "Safe delete 'T'" "true"
+class UnusedTypeParameter<<caret>T, P>(val p: P)

idea/tests/org/jetbrains/kotlin/idea/quickfix/AbstractQuickFixTest.java

@@ -26,9 +26,11 @@ import com.intellij.openapi.projectRoots.JavaSdk;
 import com.intellij.openapi.projectRoots.Sdk;
 import com.intellij.openapi.startup.StartupManager;
 import com.intellij.openapi.util.Pair;
+import com.intellij.openapi.util.io.FileUtil;
 import com.intellij.psi.PsiElement;
 import org.apache.commons.lang.SystemUtils;
 import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
 import org.jetbrains.kotlin.idea.DirectiveBasedActionUtils;
 import org.jetbrains.kotlin.idea.KotlinLightQuickFixTestCase;
 import org.jetbrains.kotlin.idea.PluginTestCaseBase;
@@ -39,6 +41,7 @@ import org.jetbrains.kotlin.test.TestMetadata;
 import org.junit.Assert;
 
 import java.io.File;
+import java.io.IOException;
 import java.util.HashSet;
 import java.util.List;
 import java.util.Set;
@@ -50,6 +53,19 @@ public abstract class AbstractQuickFixTest extends KotlinLightQuickFixTestCase {
         ((StartupManagerImpl) StartupManager.getInstance(getProject())).runPostStartupActivities();
     }
 
+    @Nullable
+    private static File findInspectionFile(@NotNull File startDir) {
+        File currentDir = startDir;
+        while (currentDir != null) {
+            File inspectionFile = new File(currentDir, ".inspection");
+            if (inspectionFile.exists()) {
+                return inspectionFile;
+            }
+            currentDir = currentDir.getParentFile();
+        }
+        return null;
+    }
+
     protected void doTest(@NotNull String beforeFileName) throws Exception {
         boolean isWithRuntime = beforeFileName.endsWith("Runtime.kt");
 
@@ -58,6 +74,8 @@ public abstract class AbstractQuickFixTest extends KotlinLightQuickFixTestCase {
                 ConfigLibraryUtil.configureKotlinRuntime(getModule(), getFullJavaJDK());
             }
 
+            enableInspections(beforeFileName);
+
             doSingleTest(getTestName(false) + ".kt");
             checkForUnexpectedActions();
             checkForUnexpectedErrors();
@@ -69,6 +87,15 @@ public abstract class AbstractQuickFixTest extends KotlinLightQuickFixTestCase {
         }
     }
 
+    private void enableInspections(String beforeFileName) throws IOException, ClassNotFoundException {
+        File inspectionFile = findInspectionFile(new File(beforeFileName).getParentFile());
+        if (inspectionFile != null) {
+            String className = FileUtil.loadFile(inspectionFile).trim();
+            Class<?> inspectionClass = Class.forName(className);
+            enableInspectionTools(inspectionClass);
+        }
+    }
+
     private void checkForUnexpectedActions() throws ClassNotFoundException {
         String text = getEditor().getDocument().getText();
         Pair<String, Boolean> pair = parseActionHintImpl(getFile(), text);

idea/tests/org/jetbrains/kotlin/idea/quickfix/QuickFixTestGenerated.java

@@ -30,7 +30,7 @@ import java.util.regex.Pattern;
 @SuppressWarnings("all")
 @TestMetadata("idea/testData/quickfix")
 @TestDataPath("$PROJECT_ROOT")
-@InnerTestClasses({QuickFixTestGenerated.Abstract.class, QuickFixTestGenerated.AddStarProjections.class, QuickFixTestGenerated.AutoImports.class, QuickFixTestGenerated.ChangeSignature.class, QuickFixTestGenerated.CheckArguments.class, QuickFixTestGenerated.ConflictingImports.class, QuickFixTestGenerated.CreateFromUsage.class, QuickFixTestGenerated.Expressions.class, QuickFixTestGenerated.Migration.class, QuickFixTestGenerated.Modifiers.class, QuickFixTestGenerated.Nullables.class, QuickFixTestGenerated.Override.class, QuickFixTestGenerated.PlatformClasses.class, QuickFixTestGenerated.Supercalls.class, QuickFixTestGenerated.SupertypeInitialization.class, QuickFixTestGenerated.Suppress.class, QuickFixTestGenerated.TypeAddition.class, QuickFixTestGenerated.TypeImports.class, QuickFixTestGenerated.TypeMismatch.class, QuickFixTestGenerated.TypeProjection.class, QuickFixTestGenerated.Variables.class, QuickFixTestGenerated.When.class})
+@InnerTestClasses({QuickFixTestGenerated.Abstract.class, QuickFixTestGenerated.AddStarProjections.class, QuickFixTestGenerated.AutoImports.class, QuickFixTestGenerated.ChangeSignature.class, QuickFixTestGenerated.CheckArguments.class, QuickFixTestGenerated.ConflictingImports.class, QuickFixTestGenerated.CreateFromUsage.class, QuickFixTestGenerated.Expressions.class, QuickFixTestGenerated.Migration.class, QuickFixTestGenerated.Modifiers.class, QuickFixTestGenerated.Nullables.class, QuickFixTestGenerated.Override.class, QuickFixTestGenerated.PlatformClasses.class, QuickFixTestGenerated.RemoveUnused.class, QuickFixTestGenerated.Supercalls.class, QuickFixTestGenerated.SupertypeInitialization.class, QuickFixTestGenerated.Suppress.class, QuickFixTestGenerated.TypeAddition.class, QuickFixTestGenerated.TypeImports.class, QuickFixTestGenerated.TypeMismatch.class, QuickFixTestGenerated.TypeProjection.class, QuickFixTestGenerated.Variables.class, QuickFixTestGenerated.When.class})
 @RunWith(JUnit3RunnerWithInners.class)
 public class QuickFixTestGenerated extends AbstractQuickFixTest {
     public void testAllFilesPresentInQuickfix() throws Exception {
@@ -3423,6 +3423,45 @@ public class QuickFixTestGenerated extends AbstractQuickFixTest {
         }
     }
 
+    @TestMetadata("idea/testData/quickfix/removeUnused")
+    @TestDataPath("$PROJECT_ROOT")
+    @RunWith(JUnit3RunnerWithInners.class)
+    public static class RemoveUnused extends AbstractQuickFixTest {
+        public void testAllFilesPresentInRemoveUnused() throws Exception {
+            JetTestUtils.assertAllTestsPresentByMetadata(this.getClass(), new File("idea/testData/quickfix/removeUnused"), Pattern.compile("^before(\\w+)\\.kt$"), true);
+        }
+
+        @TestMetadata("beforeUnusedClass.kt")
+        public void testUnusedClass() throws Exception {
+            String fileName = JetTestUtils.navigationMetadata("idea/testData/quickfix/removeUnused/beforeUnusedClass.kt");
+            doTest(fileName);
+        }
+
+        @TestMetadata("beforeUnusedFunction.kt")
+        public void testUnusedFunction() throws Exception {
+            String fileName = JetTestUtils.navigationMetadata("idea/testData/quickfix/removeUnused/beforeUnusedFunction.kt");
+            doTest(fileName);
+        }
+
+        @TestMetadata("beforeUnusedProperty.kt")
+        public void testUnusedProperty() throws Exception {
+            String fileName = JetTestUtils.navigationMetadata("idea/testData/quickfix/removeUnused/beforeUnusedProperty.kt");
+            doTest(fileName);
+        }
+
+        @TestMetadata("beforeUnusedPropertyAsConstructorParameter.kt")
+        public void testUnusedPropertyAsConstructorParameter() throws Exception {
+            String fileName = JetTestUtils.navigationMetadata("idea/testData/quickfix/removeUnused/beforeUnusedPropertyAsConstructorParameter.kt");
+            doTest(fileName);
+        }
+
+        @TestMetadata("beforeUnusedTypeParameter.kt")
+        public void testUnusedTypeParameter() throws Exception {
+            String fileName = JetTestUtils.navigationMetadata("idea/testData/quickfix/removeUnused/beforeUnusedTypeParameter.kt");
+            doTest(fileName);
+        }
+    }
+
     @TestMetadata("idea/testData/quickfix/supercalls")
     @TestDataPath("$PROJECT_ROOT")
     @RunWith(JUnit3RunnerWithInners.class)