Quick-fix "wrap with safe let call" introduced #KT-11104 Fixed

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

@@ -194,6 +194,10 @@ class QuickFixRegistrar : QuickFixContributor {
         UNSAFE_IMPLICIT_INVOKE_CALL.registerFactory(SurroundWithNullCheckFix)
         UNSAFE_INFIX_CALL.registerFactory(SurroundWithNullCheckFix)
 
+        UNSAFE_CALL.registerFactory(WrapWithSafeLetCallFix)
+        UNSAFE_IMPLICIT_INVOKE_CALL.registerFactory(WrapWithSafeLetCallFix)
+        UNSAFE_INFIX_CALL.registerFactory(WrapWithSafeLetCallFix)
+
         UNSAFE_CALL.registerFactory(AddExclExclCallFix)
         UNNECESSARY_NOT_NULL_ASSERTION.registerFactory(RemoveExclExclCallFix)
         UNSAFE_INFIX_CALL.registerFactory(ReplaceInfixCallFix)

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

@@ -0,0 +1,54 @@
+/*
+ * Copyright 2010-2016 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 org.jetbrains.kotlin.idea.quickfix
+
+import com.intellij.codeInsight.intention.IntentionAction
+import com.intellij.openapi.editor.Editor
+import com.intellij.openapi.project.Project
+import org.jetbrains.kotlin.diagnostics.Diagnostic
+import org.jetbrains.kotlin.psi.*
+import org.jetbrains.kotlin.psi.psiUtil.getParentOfType
+
+class WrapWithSafeLetCallFix(
+        expression: KtExpression,
+        val nullableExpression: KtExpression
+) : KotlinQuickFixAction<KtExpression>(expression) {
+
+    override fun getFamilyName() = text
+
+    override fun getText() = "Wrap with '?.let { ... }' call"
+
+    override fun invoke(project: Project, editor: Editor?, file: KtFile) {
+        val factory = KtPsiFactory(element)
+        val nullableText = nullableExpression.text
+        nullableExpression.replace(factory.createExpression("it"))
+        val wrapped = factory.createExpressionByPattern("$0?.let { $1 }", nullableText, element.text)
+        element.replace(wrapped)
+    }
+
+    companion object : KotlinSingleIntentionActionFactory() {
+        override fun createAction(diagnostic: Diagnostic): IntentionAction? {
+            val element = diagnostic.psiElement
+            val expression = element.getParentOfType<KtExpression>(true) ?: return null
+
+            val parent = element.parent
+            val nullableExpression = (parent as? KtCallExpression)?.calleeExpression ?: return null
+
+            return WrapWithSafeLetCallFix(expression, nullableExpression)
+        }
+    }
+}