"Nested lambda has shadowed implicit parameter": Do not report if 'it' paramerter is not used #KT-26268 Fixed

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

@@ -15,20 +15,22 @@ import com.intellij.psi.PsiElementVisitor
 import org.jetbrains.kotlin.idea.caches.resolve.analyze
 import org.jetbrains.kotlin.idea.refactoring.rename.KotlinVariableInplaceRenameHandler
 import org.jetbrains.kotlin.psi.*
-import org.jetbrains.kotlin.psi.psiUtil.getOrCreateParameterList
-import org.jetbrains.kotlin.psi.psiUtil.getParentOfTypesAndPredicate
-import org.jetbrains.kotlin.psi.psiUtil.getStrictParentOfType
-import org.jetbrains.kotlin.psi.psiUtil.startOffset
+import org.jetbrains.kotlin.psi.psiUtil.*
 import org.jetbrains.kotlin.resolve.BindingContext
+import org.jetbrains.kotlin.resolve.calls.callUtil.getResolvedCall
 import org.jetbrains.kotlin.resolve.lazy.BodyResolveMode
 
 class NestedLambdaShadowedImplicitParameterInspection : AbstractKotlinInspection() {
 
     override fun buildVisitor(holder: ProblemsHolder, isOnTheFly: Boolean): PsiElementVisitor {
         return lambdaExpressionVisitor(fun(lambda: KtLambdaExpression) {
-            val context: BindingContext by lazy { lambda.analyze(BodyResolveMode.PARTIAL) }
-            if (lambda.valueParameters.isNotEmpty() || lambda.functionDescriptor(context)?.valueParameters?.size != 1) return
+            if (lambda.valueParameters.isNotEmpty()) return
+            val context = lambda.analyze(BodyResolveMode.PARTIAL)
+            val implicitParameter = lambda.functionDescriptor(context)?.valueParameters?.singleOrNull() ?: return
             if (lambda.getParentImplicitParameterLambda(context) == null) return
+            if (lambda.findDescendantOfType<KtNameReferenceExpression> {
+                    it.text == "it" && it.getResolvedCall(context)?.resultingDescriptor == implicitParameter
+                } == null) return
             val callee = lambda.getStrictParentOfType<KtCallExpression>()?.calleeExpression ?: return
             holder.registerProblem(
                 callee,

idea/testData/inspectionsLocal/nestedLambdaShadowedImplicitParameter/implicit.kt

@@ -1,8 +1,10 @@
 fun foo(f: (String) -> Unit) {}
+fun bar(s: String) {}
 
 fun test() {
     foo {
         <caret>foo {
+            bar(it)
         }
     }
 }

idea/testData/inspectionsLocal/nestedLambdaShadowedImplicitParameter/implicit.kt.after

@@ -1,8 +1,10 @@
 fun foo(f: (String) -> Unit) {}
+fun bar(s: String) {}
 
 fun test() {
     foo { it ->
         foo {
+            bar(it)
         }
     }
 }

idea/testData/inspectionsLocal/nestedLambdaShadowedImplicitParameter/implicitGrandParent.kt

@@ -1,9 +1,11 @@
 fun foo(f: (String) -> Unit) {}
+fun bar(s: String) {}
 
 fun test() {
     foo {
         foo { s ->
             <caret>foo {
+                bar(it)
             }
         }
     }

idea/testData/inspectionsLocal/nestedLambdaShadowedImplicitParameter/implicitGrandParent.kt.after

@@ -1,9 +1,11 @@
 fun foo(f: (String) -> Unit) {}
+fun bar(s: String) {}
 
 fun test() {
     foo { it ->
         foo { s ->
             foo {
+                bar(it)
             }
         }
     }

idea/testData/inspectionsLocal/nestedLambdaShadowedImplicitParameter/notUseParameter.kt

@@ -0,0 +1,10 @@
+// PROBLEM: none
+
+fun foo(f: (String) -> Unit) {}
+
+fun test() {
+    foo {
+        <caret>foo {
+        }
+    }
+}

idea/tests/org/jetbrains/kotlin/idea/inspections/LocalInspectionTestGenerated.java

@@ -3471,6 +3471,11 @@ public class LocalInspectionTestGenerated extends AbstractLocalInspectionTest {
             runTest("idea/testData/inspectionsLocal/nestedLambdaShadowedImplicitParameter/implicitGrandParent.kt");
         }
 
+        @TestMetadata("notUseParameter.kt")
+        public void testNotUseParameter() throws Exception {
+            runTest("idea/testData/inspectionsLocal/nestedLambdaShadowedImplicitParameter/notUseParameter.kt");
+        }
+
         @TestMetadata("receiver.kt")
         public void testReceiver() throws Exception {
             runTest("idea/testData/inspectionsLocal/nestedLambdaShadowedImplicitParameter/receiver.kt");