Wrap with let: apply to unsafe qualified expression

#KT-18125 Fixed

idea/src/org/jetbrains/kotlin/idea/quickfix/WrapWithSafeLetCallFix.kt

@@ -31,10 +31,9 @@ import org.jetbrains.kotlin.idea.core.NewDeclarationNameValidator
 import org.jetbrains.kotlin.idea.references.mainReference
 import org.jetbrains.kotlin.idea.search.usagesSearch.descriptor
 import org.jetbrains.kotlin.psi.*
-import org.jetbrains.kotlin.psi.psiUtil.createSmartPointer
-import org.jetbrains.kotlin.psi.psiUtil.getLastParentOfTypeInRow
-import org.jetbrains.kotlin.psi.psiUtil.getParentOfType
-import org.jetbrains.kotlin.psi.psiUtil.getQualifiedExpressionForSelector
+import org.jetbrains.kotlin.psi.psiUtil.*
+import org.jetbrains.kotlin.resolve.calls.callUtil.getParameterForArgument
+import org.jetbrains.kotlin.types.isNullable
 import org.jetbrains.kotlin.types.typeUtil.isNullabilityMismatch
 
 class WrapWithSafeLetCallFix(
@@ -83,18 +82,23 @@ class WrapWithSafeLetCallFix(
     object UnsafeFactory : KotlinSingleIntentionActionFactory() {
         override fun createAction(diagnostic: Diagnostic): IntentionAction? {
             val element = diagnostic.psiElement
-
             if (element is KtNameReferenceExpression) {
                 val resolvedCall = element.resolveToCall()
                 if (resolvedCall?.call?.callType != Call.CallType.INVOKE) return null
             }
-
-            val expression = element.getParentOfType<KtExpression>(true) ?: return null
-
-            val parent = element.parent
-            val nullableExpression = (parent as? KtCallExpression)?.calleeExpression ?: return null
-
-            return WrapWithSafeLetCallFix(expression, nullableExpression)
+            val expression = element.getStrictParentOfType<KtExpression>() ?: return null
+            val (targetExpression, nullableExpression) = if (expression is KtQualifiedExpression) {
+                val argument = expression.parent as? KtValueArgument ?: return null
+                val call = argument.getStrictParentOfType<KtCallExpression>() ?: return null
+                val parameter = call.resolveToCall()?.getParameterForArgument(argument) ?: return null
+                if (parameter.type.isNullable()) return null
+                val targetExpression = call.getLastParentOfTypeInRow<KtQualifiedExpression>() ?: call
+                targetExpression to expression.receiverExpression
+            } else {
+                val nullableExpression = (element.parent as? KtCallExpression)?.calleeExpression ?: return null
+                expression to nullableExpression
+            }
+            return WrapWithSafeLetCallFix(targetExpression, nullableExpression)
         }
     }
 

idea/testData/quickfix/wrapWithSafeLetCall/unsafe.kt

@@ -0,0 +1,7 @@
+// "Wrap with '?.let { ... }' call" "true"
+// WITH_RUNTIME
+fun foo(s: String) {}
+
+fun bar(s: String?) {
+    foo(s<caret>.substring(1))
+}

idea/testData/quickfix/wrapWithSafeLetCall/unsafe.kt.after

@@ -0,0 +1,7 @@
+// "Wrap with '?.let { ... }' call" "true"
+// WITH_RUNTIME
+fun foo(s: String) {}
+
+fun bar(s: String?) {
+    s?.let { foo(it.substring(1)) }
+}

idea/testData/quickfix/wrapWithSafeLetCall/unsafe2.kt

@@ -0,0 +1,13 @@
+// "Wrap with '?.let { ... }' call" "true"
+// WITH_RUNTIME
+class A(val b: B)
+class B {
+    fun c(s: String) {}
+}
+
+class X(val y: Y)
+class Y(val z: String)
+
+fun test(a: A, x: X?) {
+    a.b.c(x?.y<caret>.z)
+}

idea/testData/quickfix/wrapWithSafeLetCall/unsafe2.kt.after

@@ -0,0 +1,13 @@
+// "Wrap with '?.let { ... }' call" "true"
+// WITH_RUNTIME
+class A(val b: B)
+class B {
+    fun c(s: String) {}
+}
+
+class X(val y: Y)
+class Y(val z: String)
+
+fun test(a: A, x: X?) {
+    x?.y?.let { a.b.c(it.z) }
+}

idea/testData/quickfix/wrapWithSafeLetCall/unsafeForNullableParameter.kt

@@ -0,0 +1,12 @@
+// "Wrap with '?.let { ... }' call" "false"
+// ACTION: Add 's =' to argument
+// ACTION: Add non-null asserted (!!) call
+// ACTION: Replace with safe (?.) call
+// ACTION: Surround with null check
+// DISABLE-ERRORS
+// WITH_RUNTIME
+fun foo(s: String?) {}
+
+fun bar(s: String?) {
+    foo(s<caret>.substring(1))
+}

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

@@ -15529,6 +15529,21 @@ public class QuickFixTestGenerated extends AbstractQuickFixTest {
             runTest("idea/testData/quickfix/wrapWithSafeLetCall/objectQualifier.kt");
         }
 
+        @TestMetadata("unsafe.kt")
+        public void testUnsafe() throws Exception {
+            runTest("idea/testData/quickfix/wrapWithSafeLetCall/unsafe.kt");
+        }
+
+        @TestMetadata("unsafe2.kt")
+        public void testUnsafe2() throws Exception {
+            runTest("idea/testData/quickfix/wrapWithSafeLetCall/unsafe2.kt");
+        }
+
+        @TestMetadata("unsafeForNullableParameter.kt")
+        public void testUnsafeForNullableParameter() throws Exception {
+            runTest("idea/testData/quickfix/wrapWithSafeLetCall/unsafeForNullableParameter.kt");
+        }
+
         @TestMetadata("unstableValue.kt")
         public void testUnstableValue() throws Exception {
             runTest("idea/testData/quickfix/wrapWithSafeLetCall/unstableValue.kt");