Introduce intention 'expr.unsafeCast<Type>()' <- -> 'expr as Type'

So #KT-16382 Fixed

idea/src/META-INF/plugin.xml

@@ -1539,6 +1539,16 @@
       <category>Kotlin</category>
     </intentionAction>
 
+    <intentionAction>
+      <className>org.jetbrains.kotlin.idea.intentions.ConvertUnsafeCastCallToUnsafeCastIntention</className>
+      <category>Kotlin</category>
+    </intentionAction>
+
+    <intentionAction>
+      <className>org.jetbrains.kotlin.idea.intentions.ConvertUnsafeCastToUnsafeCastCallIntention</className>
+      <category>Kotlin</category>
+    </intentionAction>
+
     <localInspection implementationClass="org.jetbrains.kotlin.idea.intentions.ObjectLiteralToLambdaInspection"
                      displayName="Object literal can be converted to lambda"
                      groupPath="Kotlin"

idea/src/org/jetbrains/kotlin/idea/intentions/ConvertUnsafeCastCallToUnsafeCastIntention.kt

@@ -0,0 +1,41 @@
+/*
+ * Copyright 2000-2018 JetBrains s.r.o. Use of this source code is governed by the Apache 2.0 license
+ * that can be found in the license/LICENSE.txt file.
+ */
+
+package org.jetbrains.kotlin.idea.intentions
+
+import com.intellij.openapi.editor.Editor
+import org.jetbrains.kotlin.idea.caches.resolve.analyze
+import org.jetbrains.kotlin.idea.project.platform
+import org.jetbrains.kotlin.js.resolve.JsPlatform
+import org.jetbrains.kotlin.psi.*
+import org.jetbrains.kotlin.resolve.calls.callUtil.getResolvedCall
+import org.jetbrains.kotlin.resolve.descriptorUtil.fqNameOrNull
+import org.jetbrains.kotlin.resolve.lazy.BodyResolveMode
+
+class ConvertUnsafeCastCallToUnsafeCastIntention : SelfTargetingIntention<KtDotQualifiedExpression>(
+    KtDotQualifiedExpression::class.java, "Convert to unsafe cast"
+) {
+
+    override fun isApplicableTo(element: KtDotQualifiedExpression, caretOffset: Int): Boolean {
+        if (element.platform != JsPlatform) return false
+        if ((element.selectorExpression as? KtCallExpression)?.calleeExpression?.text != "unsafeCast") return false
+
+        val context = element.analyze(BodyResolveMode.PARTIAL)
+        val fqName = element.getResolvedCall(context)?.resultingDescriptor?.fqNameOrNull()?.asString() ?: return false
+        if (fqName != "kotlin.js.unsafeCast") return false
+
+        val type = element.callExpression?.typeArguments?.singleOrNull() ?: return false
+
+        text = "Convert to '${element.receiverExpression.text} as ${type.text}'"
+        return true
+    }
+
+    override fun applyTo(element: KtDotQualifiedExpression, editor: Editor?) {
+        val type = element.callExpression?.typeArguments?.singleOrNull() ?: return
+        val newExpression = KtPsiFactory(element).createExpressionByPattern("$0 as $1", element.receiverExpression, type.text)
+        element.replace(newExpression)
+    }
+
+}

idea/src/org/jetbrains/kotlin/idea/intentions/ConvertUnsafeCastToUnsafeCastCallIntention.kt

@@ -0,0 +1,44 @@
+/*
+ * Copyright 2000-2018 JetBrains s.r.o. Use of this source code is governed by the Apache 2.0 license
+ * that can be found in the license/LICENSE.txt file.
+ */
+
+package org.jetbrains.kotlin.idea.intentions
+
+import com.intellij.openapi.editor.Editor
+import org.jetbrains.kotlin.idea.caches.resolve.analyze
+import org.jetbrains.kotlin.idea.project.platform
+import org.jetbrains.kotlin.js.resolve.JsPlatform
+import org.jetbrains.kotlin.lexer.KtTokens
+import org.jetbrains.kotlin.psi.KtBinaryExpressionWithTypeRHS
+import org.jetbrains.kotlin.psi.KtPsiFactory
+import org.jetbrains.kotlin.psi.createExpressionByPattern
+import org.jetbrains.kotlin.resolve.BindingContext
+import org.jetbrains.kotlin.resolve.lazy.BodyResolveMode
+import org.jetbrains.kotlin.types.TypeUtils
+
+class ConvertUnsafeCastToUnsafeCastCallIntention : SelfTargetingIntention<KtBinaryExpressionWithTypeRHS>(
+    KtBinaryExpressionWithTypeRHS::class.java, "Convert to unsafeCast() call"
+) {
+
+    override fun isApplicableTo(element: KtBinaryExpressionWithTypeRHS, caretOffset: Int): Boolean {
+        if (element.platform != JsPlatform) return false
+
+        if (element.operationReference.getReferencedNameElementType() != KtTokens.AS_KEYWORD) return false
+
+        val right = element.right ?: return false
+        val context = right.analyze(BodyResolveMode.PARTIAL)
+        val type = context[BindingContext.TYPE, right] ?: return false
+        if (TypeUtils.isNullableType(type)) return false
+
+        text = "Convert to '${element.left.text}.unsafeCast<${right.text}>()'"
+        return true
+    }
+
+    override fun applyTo(element: KtBinaryExpressionWithTypeRHS, editor: Editor?) {
+        val right = element.right ?: return
+        val newExpression = KtPsiFactory(element).createExpressionByPattern("$0.unsafeCast<$1>()", element.left, right)
+        element.replace(newExpression)
+    }
+
+}