FIR IDE: make unused variable fix a IDE inspection

GitOrigin-RevId: 7908d577d3dc4e9b85781a3250f5090f39ba7c64

plugins/kotlin/fir/src/org/jetbrains/kotlin/idea/fir/applicators/ApplicabilityRanges.kt

@@ -7,11 +7,9 @@ import com.intellij.psi.PsiElement
 import com.intellij.psi.tree.TokenSet
 import org.jetbrains.kotlin.idea.fir.api.applicator.applicabilityRanges
 import org.jetbrains.kotlin.idea.fir.api.applicator.applicabilityTarget
+import org.jetbrains.kotlin.idea.util.nameIdentifierTextRangeInThis
 import org.jetbrains.kotlin.lexer.KtTokens
-import org.jetbrains.kotlin.psi.KtCallableDeclaration
-import org.jetbrains.kotlin.psi.KtLambdaExpression
-import org.jetbrains.kotlin.psi.KtModifierListOwner
-import org.jetbrains.kotlin.psi.KtValueArgument
+import org.jetbrains.kotlin.psi.*
 
 object ApplicabilityRanges {
     val SELF = applicabilityTarget<PsiElement> { it }
@@ -37,4 +35,8 @@ object ApplicabilityRanges {
             listOf(TextRange(0, element.textLength))
         }
     }
+
+    val DECLARATION_NAME = applicabilityTarget<KtNamedDeclaration> {  element ->
+        element.nameIdentifier
+    }
 }

plugins/kotlin/fir/src/org/jetbrains/kotlin/idea/fir/inspections/diagnosticBased/HLUnusedVariableInspection.kt

@@ -0,0 +1,50 @@
+// Copyright 2000-2021 JetBrains s.r.o. and contributors. Use of this source code is governed by the Apache 2.0 license that can be found in the LICENSE file.
+
+package org.jetbrains.kotlin.idea.fir.inspections.diagnosticBased
+
+import org.jetbrains.kotlin.idea.quickfix.RemovePsiElementSimpleFix
+import com.intellij.codeInspection.ProblemHighlightType
+import org.jetbrains.kotlin.analysis.api.fir.diagnostics.KtFirDiagnostic
+import org.jetbrains.kotlin.idea.KotlinBundle
+import org.jetbrains.kotlin.idea.api.applicator.HLApplicator
+import org.jetbrains.kotlin.idea.api.applicator.HLApplicatorInput
+import org.jetbrains.kotlin.idea.api.applicator.applicator
+import org.jetbrains.kotlin.idea.fir.api.AbstractHLDiagnosticBasedInspection
+import org.jetbrains.kotlin.idea.fir.api.HLInputByDiagnosticProvider
+import org.jetbrains.kotlin.idea.fir.api.applicator.HLApplicabilityRange
+import org.jetbrains.kotlin.idea.fir.api.applicator.HLPresentation
+import org.jetbrains.kotlin.idea.fir.api.applicator.presentation
+import org.jetbrains.kotlin.idea.fir.api.inputByDiagnosticProvider
+import org.jetbrains.kotlin.idea.fir.applicators.ApplicabilityRanges
+import org.jetbrains.kotlin.idea.util.isExplicitTypeReferenceNeededForTypeInference
+import org.jetbrains.kotlin.psi.KtNamedDeclaration
+import org.jetbrains.kotlin.psi.KtProperty
+
+class HLUnusedVariableInspection :
+    AbstractHLDiagnosticBasedInspection<KtNamedDeclaration, KtFirDiagnostic.UnusedVariable, HLApplicatorInput.Empty>(
+        elementType = KtNamedDeclaration::class,
+        diagnosticType = KtFirDiagnostic.UnusedVariable::class,
+    ) {
+    override val inputByDiagnosticProvider: HLInputByDiagnosticProvider<KtNamedDeclaration, KtFirDiagnostic.UnusedVariable, HLApplicatorInput.Empty>
+        get() = inputByDiagnosticProvider { diagnostic ->
+            val ktProperty = diagnostic.psi as? KtProperty ?: return@inputByDiagnosticProvider null
+            if (ktProperty.isExplicitTypeReferenceNeededForTypeInference()) return@inputByDiagnosticProvider null
+            HLApplicatorInput.Empty
+        }
+    override val presentation: HLPresentation<KtNamedDeclaration>
+        get() = presentation {
+            highlightType(ProblemHighlightType.LIKE_UNUSED_SYMBOL)
+        }
+    override val applicabilityRange: HLApplicabilityRange<KtNamedDeclaration>
+        get() = ApplicabilityRanges.DECLARATION_NAME
+    override val applicator: HLApplicator<KtNamedDeclaration, HLApplicatorInput.Empty>
+        get() = applicator {
+            familyName(KotlinBundle.message("remove.element"))
+            actionName { psi, _ ->
+                KotlinBundle.message("remove.variable.0", psi.name.toString())
+            }
+            applyTo { psi, _ ->
+                RemovePsiElementSimpleFix.RemoveVariableFactory.removeProperty(psi as KtProperty)
+            }
+        }
+}

plugins/kotlin/fir/src/org/jetbrains/kotlin/idea/quickfix/MainKtQuickFixRegistrar.kt

@@ -176,10 +176,6 @@ class MainKtQuickFixRegistrar : KtQuickFixRegistrar() {
         registerPsiQuickFixes(KtFirDiagnostic.NonVarargSpread::class, RemovePsiElementSimpleFix.RemoveSpreadFactory)
     }
 
-    private val unused = KtQuickFixesListBuilder.registerPsiQuickFix {
-        registerPsiQuickFixes(KtFirDiagnostic.UnusedVariable::class, RemovePsiElementSimpleFix.RemoveVariableFactory)
-    }
-
     override val list: KtQuickFixesList = KtQuickFixesList.createCombined(
         keywords,
         propertyInitialization,
@@ -191,6 +187,5 @@ class MainKtQuickFixRegistrar : KtQuickFixRegistrar() {
         typeMismatch,
         superKeyword,
         vararg,
-        unused,
     )
 }

plugins/kotlin/fir/test/org/jetbrains/kotlin/idea/fir/inspections/HLLocalInspectionTestGenerated.java

@@ -18,6 +18,64 @@ import org.junit.runner.RunWith;
 @TestDataPath("$CONTENT_ROOT")
 @RunWith(JUnit3RunnerWithInners.class)
 public abstract class HLLocalInspectionTestGenerated extends AbstractHLLocalInspectionTest {
+    @RunWith(JUnit3RunnerWithInners.class)
+    @TestMetadata("../idea/tests/testData/inspectionsLocal/unusedVariable")
+    public static class UnusedVariable extends AbstractHLLocalInspectionTest {
+        private void runTest(String testDataFilePath) throws Exception {
+            KotlinTestUtils.runTest(this::doTest, this, testDataFilePath);
+        }
+
+        @TestMetadata("unusedVariableInDestructuringDeclaration.kt")
+        public void testUnusedVariableInDestructuringDeclaration() throws Exception {
+            runTest("../idea/tests/testData/inspectionsLocal/unusedVariable/unusedVariableInDestructuringDeclaration.kt");
+        }
+
+        @TestMetadata("unusedVariableWithAnonymousFunctionInitialize1.kt")
+        public void testUnusedVariableWithAnonymousFunctionInitialize1() throws Exception {
+            runTest("../idea/tests/testData/inspectionsLocal/unusedVariable/unusedVariableWithAnonymousFunctionInitialize1.kt");
+        }
+
+        @TestMetadata("unusedVariableWithAnonymousFunctionInitialize2.kt")
+        public void testUnusedVariableWithAnonymousFunctionInitialize2() throws Exception {
+            runTest("../idea/tests/testData/inspectionsLocal/unusedVariable/unusedVariableWithAnonymousFunctionInitialize2.kt");
+        }
+
+        @TestMetadata("unusedVariableWithConstantInitializer.kt")
+        public void testUnusedVariableWithConstantInitializer() throws Exception {
+            runTest("../idea/tests/testData/inspectionsLocal/unusedVariable/unusedVariableWithConstantInitializer.kt");
+        }
+
+        @TestMetadata("unusedVariableWithInitializer.kt")
+        public void testUnusedVariableWithInitializer() throws Exception {
+            runTest("../idea/tests/testData/inspectionsLocal/unusedVariable/unusedVariableWithInitializer.kt");
+        }
+
+        @TestMetadata("unusedVariableWithInitializerAndComment.kt")
+        public void testUnusedVariableWithInitializerAndComment() throws Exception {
+            runTest("../idea/tests/testData/inspectionsLocal/unusedVariable/unusedVariableWithInitializerAndComment.kt");
+        }
+
+        @TestMetadata("unusedVariableWithLambdaInitializer1.kt")
+        public void testUnusedVariableWithLambdaInitializer1() throws Exception {
+            runTest("../idea/tests/testData/inspectionsLocal/unusedVariable/unusedVariableWithLambdaInitializer1.kt");
+        }
+
+        @TestMetadata("unusedVariableWithLambdaInitializer2.kt")
+        public void testUnusedVariableWithLambdaInitializer2() throws Exception {
+            runTest("../idea/tests/testData/inspectionsLocal/unusedVariable/unusedVariableWithLambdaInitializer2.kt");
+        }
+
+        @TestMetadata("unusedVariableWithNullInitializer.kt")
+        public void testUnusedVariableWithNullInitializer() throws Exception {
+            runTest("../idea/tests/testData/inspectionsLocal/unusedVariable/unusedVariableWithNullInitializer.kt");
+        }
+
+        @TestMetadata("unusedVariableWithoutInitializer.kt")
+        public void testUnusedVariableWithoutInitializer() throws Exception {
+            runTest("../idea/tests/testData/inspectionsLocal/unusedVariable/unusedVariableWithoutInitializer.kt");
+        }
+    }
+
     @RunWith(JUnit3RunnerWithInners.class)
     @TestMetadata("../idea/tests/testData/inspectionsLocal/redundantVisibilityModifier")
     public static class RedundantVisibilityModifier extends AbstractHLLocalInspectionTest {

plugins/kotlin/fir/test/org/jetbrains/kotlin/idea/fir/quickfix/HighLevelQuickFixTestGenerated.java

@@ -1750,64 +1750,6 @@ public abstract class HighLevelQuickFixTestGenerated extends AbstractHighLevelQu
         }
     }
 
-    @RunWith(JUnit3RunnerWithInners.class)
-    @TestMetadata("../idea/tests/testData/quickfix/variables")
-    public static class Variables extends AbstractHighLevelQuickFixTest {
-        private void runTest(String testDataFilePath) throws Exception {
-            KotlinTestUtils.runTest(this::doTest, this, testDataFilePath);
-        }
-
-        @TestMetadata("unusedVariableInDestructuringDeclaration.kt")
-        public void testUnusedVariableInDestructuringDeclaration() throws Exception {
-            runTest("../idea/tests/testData/quickfix/variables/unusedVariableInDestructuringDeclaration.kt");
-        }
-
-        @TestMetadata("unusedVariableWithAnonymousFunctionInitialize1.kt")
-        public void testUnusedVariableWithAnonymousFunctionInitialize1() throws Exception {
-            runTest("../idea/tests/testData/quickfix/variables/unusedVariableWithAnonymousFunctionInitialize1.kt");
-        }
-
-        @TestMetadata("unusedVariableWithAnonymousFunctionInitialize2.kt")
-        public void testUnusedVariableWithAnonymousFunctionInitialize2() throws Exception {
-            runTest("../idea/tests/testData/quickfix/variables/unusedVariableWithAnonymousFunctionInitialize2.kt");
-        }
-
-        @TestMetadata("unusedVariableWithConstantInitializer.kt")
-        public void testUnusedVariableWithConstantInitializer() throws Exception {
-            runTest("../idea/tests/testData/quickfix/variables/unusedVariableWithConstantInitializer.kt");
-        }
-
-        @TestMetadata("unusedVariableWithInitializer.kt")
-        public void testUnusedVariableWithInitializer() throws Exception {
-            runTest("../idea/tests/testData/quickfix/variables/unusedVariableWithInitializer.kt");
-        }
-
-        @TestMetadata("unusedVariableWithInitializerAndComment.kt")
-        public void testUnusedVariableWithInitializerAndComment() throws Exception {
-            runTest("../idea/tests/testData/quickfix/variables/unusedVariableWithInitializerAndComment.kt");
-        }
-
-        @TestMetadata("unusedVariableWithLambdaInitializer1.kt")
-        public void testUnusedVariableWithLambdaInitializer1() throws Exception {
-            runTest("../idea/tests/testData/quickfix/variables/unusedVariableWithLambdaInitializer1.kt");
-        }
-
-        @TestMetadata("unusedVariableWithLambdaInitializer2.kt")
-        public void testUnusedVariableWithLambdaInitializer2() throws Exception {
-            runTest("../idea/tests/testData/quickfix/variables/unusedVariableWithLambdaInitializer2.kt");
-        }
-
-        @TestMetadata("unusedVariableWithNullInitializer.kt")
-        public void testUnusedVariableWithNullInitializer() throws Exception {
-            runTest("../idea/tests/testData/quickfix/variables/unusedVariableWithNullInitializer.kt");
-        }
-
-        @TestMetadata("unusedVariableWithoutInitializer.kt")
-        public void testUnusedVariableWithoutInitializer() throws Exception {
-            runTest("../idea/tests/testData/quickfix/variables/unusedVariableWithoutInitializer.kt");
-        }
-    }
-
     @RunWith(JUnit3RunnerWithInners.class)
     @TestMetadata("../idea/tests/testData/quickfix/variables/changeMutability")
     public static class ChangeMutability extends AbstractHighLevelQuickFixTest {

plugins/kotlin/frontend-independent/resources-en/messages/KotlinBundle.properties

@@ -2257,6 +2257,7 @@ inspection.overriding.deprecated.member.display.name=Overriding deprecated membe
 inspection.unsafe.cast.from.dynamic.display.name=Implicit (unsafe) cast from dynamic type
 inspection.redundant.sam.constructor.display.name=Redundant SAM constructor
 inspection.kotlin.unused.import.display.name=Unused import directive
+inspection.kotlin.unused.variable.display.name=Unused variable
 inspection.unused.receiver.parameter.display.name=Unused receiver parameter
 inspection.unused.symbol.display.name=Unused symbol
 inspection.use.property.access.syntax.display.name=Accessor call that can be replaced with property access syntax

plugins/kotlin/generators/test/org/jetbrains/kotlin/testGenerator/GenerateTests.kt

@@ -182,10 +182,10 @@ import org.jetbrains.kotlin.testGenerator.model.Patterns.KTS
 import org.jetbrains.kotlin.testGenerator.model.Patterns.KT_OR_KTS
 import org.jetbrains.kotlin.testGenerator.model.Patterns.KT_OR_KTS_WITHOUT_DOTS
 import org.jetbrains.kotlin.testGenerator.model.Patterns.KT_WITHOUT_DOTS
+import org.jetbrains.kotlin.testGenerator.model.Patterns.KT_WITHOUT_DOT_AND_FIR_PREFIX
 import org.jetbrains.kotlin.testGenerator.model.Patterns.KT_WITHOUT_FIR_PREFIX
 import org.jetbrains.kotlin.testGenerator.model.Patterns.TEST
 import org.jetbrains.kotlin.testGenerator.model.Patterns.WS_KTS
-import org.jetbrains.kotlin.testGenerator.model.Patterns.KT_WITHOUT_DOT_AND_FIR_PREFIX
 import org.jetbrains.kotlin.tools.projectWizard.cli.AbstractProjectTemplateBuildFileGenerationTest
 import org.jetbrains.kotlin.tools.projectWizard.cli.AbstractYamlBuildFileGenerationTest
 import org.jetbrains.kotlin.tools.projectWizard.wizard.AbstractProjectTemplateNewWizardProjectImportTest
@@ -516,7 +516,11 @@ private fun assembleWorkspace(): TWorkspace = workspace {
         }
 
         testClass<AbstractLocalInspectionTest> {
-            model("inspectionsLocal", pattern = Patterns.forRegex("^([\\w\\-_]+)\\.(kt|kts)$"))
+            model(
+                "inspectionsLocal", pattern = Patterns.forRegex("^([\\w\\-_]+)\\.(kt|kts)$"),
+                // In FE1.0, this is a quickfix rather than a local inspection
+                excludedDirectories = listOf("unusedVariable")
+            )
         }
 
         testClass<AbstractViewOfflineInspectionTest> {
@@ -1079,7 +1083,6 @@ private fun assembleWorkspace(): TWorkspace = workspace {
             model("quickfix/replaceWithDotCall", pattern = pattern)
             model("quickfix/replaceWithSafeCall", pattern = pattern)
             model("quickfix/supercalls", pattern = pattern)
-            model("quickfix/variables", pattern = pattern, isRecursive = false)
             model("quickfix/variables/changeMutability", pattern = pattern, isRecursive = false)
             model("quickfix/variables/removeValVarFromParameter", pattern = pattern)
             model("quickfix/when", pattern = pattern)
@@ -1133,6 +1136,7 @@ private fun assembleWorkspace(): TWorkspace = workspace {
     /*testGroup("fir", testDataPath = "..") {
         testClass<AbstractHLLocalInspectionTest> {
             val pattern = Patterns.forRegex("^([\\w\\-_]+)\\.(kt|kts)$")
+            model("idea/tests/testData/inspectionsLocal/unusedVariable", pattern = pattern)
             model("idea/tests/testData/inspectionsLocal/redundantVisibilityModifier", pattern = pattern)
             model("fir/testData/inspectionsLocal", pattern = pattern)
         }

plugins/kotlin/idea/resources-en/inspectionDescriptions/HLUnusedVariable.html

@@ -0,0 +1,5 @@
+<html>
+<body>
+This inspection reports variables that are not used.
+</body>
+</html>

plugins/kotlin/idea/tests/testData/inspectionsLocal/unusedVariable/.firInspection

@@ -0,0 +1 @@
+org.jetbrains.kotlin.idea.fir.inspections.diagnosticBased.HLUnusedVariableInspection

plugins/kotlin/idea/tests/testData/inspectionsLocal/unusedVariable/unusedVariableInDestructuringDeclaration.kt

@@ -0,0 +1,11 @@
+// PROBLEM: none
+fun test(condition: Boolean, foo: Foo) {
+    val v = if (condition) {
+        val (<caret>one, two) = foo
+        two
+    } else {
+        null
+    }
+}
+
+data class Foo(val one: String, val two: String)

plugins/kotlin/idea/tests/testData/inspectionsLocal/unusedVariable/unusedVariableWithAnonymousFunctionInitialize1.kt

@@ -0,0 +1,4 @@
+// PROBLEM: none
+fun test() {
+    val <caret>a: (String) -> Unit = fun(s) { s + s }
+}

plugins/kotlin/idea/tests/testData/inspectionsLocal/unusedVariable/unusedVariableWithAnonymousFunctionInitialize2.kt

@@ -0,0 +1,4 @@
+// "Remove variable 'a'" "true"
+fun test() {
+    val <caret>a: (String) -> Unit = fun(s: String) { s + s }
+}

plugins/kotlin/idea/tests/testData/inspectionsLocal/unusedVariable/unusedVariableWithAnonymousFunctionInitialize2.kt.after

@@ -0,0 +1,4 @@
+// "Remove variable 'a'" "true"
+fun test() {
+    fun(s: String) { s + s }
+}

plugins/kotlin/idea/tests/testData/inspectionsLocal/unusedVariable/unusedVariableWithConstantInitializer.kt

@@ -0,0 +1,5 @@
+// "Remove variable 'flag'" "true"
+
+fun foo() {
+    val <caret>flag = true
+}

plugins/kotlin/idea/tests/testData/inspectionsLocal/unusedVariable/unusedVariableWithConstantInitializer.kt.after

@@ -0,0 +1,4 @@
+// "Remove variable 'flag'" "true"
+
+fun foo() {
+}

plugins/kotlin/idea/tests/testData/inspectionsLocal/unusedVariable/unusedVariableWithInitializer.kt

@@ -0,0 +1,6 @@
+// "Remove variable 'a'" "true"
+var cnt = 5
+fun getCnt() = cnt++
+fun f() {
+    var <caret>a = getCnt()
+}

plugins/kotlin/idea/tests/testData/inspectionsLocal/unusedVariable/unusedVariableWithInitializer.kt.after

@@ -0,0 +1,6 @@
+// "Remove variable 'a'" "true"
+var cnt = 5
+fun getCnt() = cnt++
+fun f() {
+    getCnt()
+}

plugins/kotlin/idea/tests/testData/inspectionsLocal/unusedVariable/unusedVariableWithInitializerAndComment.kt

@@ -0,0 +1,6 @@
+// "Remove variable 'a'" "true"
+var cnt = 5
+fun getCnt() = cnt++
+fun f() {
+    var <caret>a = getCnt() // comment
+}

plugins/kotlin/idea/tests/testData/inspectionsLocal/unusedVariable/unusedVariableWithInitializerAndComment.kt.after

@@ -0,0 +1,6 @@
+// "Remove variable 'a'" "true"
+var cnt = 5
+fun getCnt() = cnt++
+fun f() {
+    getCnt() // comment
+}

plugins/kotlin/idea/tests/testData/inspectionsLocal/unusedVariable/unusedVariableWithLambdaInitializer1.kt

@@ -0,0 +1,4 @@
+// PROBLEM: none
+fun test() {
+    val <caret>a: (String) -> Unit = { s -> s + s }
+}

plugins/kotlin/idea/tests/testData/inspectionsLocal/unusedVariable/unusedVariableWithLambdaInitializer2.kt

@@ -0,0 +1,4 @@
+// "Remove variable 'a'" "true"
+fun test() {
+    val <caret>a: (String) -> Unit = { s: String -> s + s }
+}

plugins/kotlin/idea/tests/testData/inspectionsLocal/unusedVariable/unusedVariableWithLambdaInitializer2.kt.after

@@ -0,0 +1,4 @@
+// "Remove variable 'a'" "true"
+fun test() {
+    { s: String -> s + s }
+}

plugins/kotlin/idea/tests/testData/inspectionsLocal/unusedVariable/unusedVariableWithNullInitializer.kt

@@ -0,0 +1,5 @@
+// "Remove variable 'i'" "true"
+
+fun foo() {
+    val <caret>i: Int? = null
+}

plugins/kotlin/idea/tests/testData/inspectionsLocal/unusedVariable/unusedVariableWithNullInitializer.kt.after

@@ -0,0 +1,4 @@
+// "Remove variable 'i'" "true"
+
+fun foo() {
+}

plugins/kotlin/idea/tests/testData/inspectionsLocal/unusedVariable/unusedVariableWithoutInitializer.kt

@@ -0,0 +1,4 @@
+// "Remove variable 'test'" "true"
+fun f() {
+    val <caret>test: Int
+}

plugins/kotlin/idea/tests/testData/inspectionsLocal/unusedVariable/unusedVariableWithoutInitializer.kt.after

@@ -0,0 +1,3 @@
+// "Remove variable 'test'" "true"
+fun f() {
+}

plugins/kotlin/resources-fir/resources/META-INF/firInspections.xml

@@ -26,5 +26,14 @@
                      level="WARNING"
                      language="kotlin"
                      key="inspection.kotlin.unused.import.display.name" bundle="messages.KotlinBundle"/>
+
+    <localInspection implementationClass="org.jetbrains.kotlin.idea.fir.inspections.diagnosticBased.HLUnusedVariableInspection"
+                     groupPath="Kotlin"
+                     groupName="Redundant constructs"
+                     enabledByDefault="true"
+                     cleanupTool="true"
+                     level="WARNING"
+                     language="kotlin"
+                     key="inspection.kotlin.unused.variable.display.name" bundle="messages.KotlinBundle"/>
   </extensions>
 </idea-plugin>