False positive removed in replace single line let intention #KT-14791 Fixed

idea/testData/intentions/replaceSingleLineLetIntention/assignment.kt

@@ -0,0 +1,8 @@
+// IS_APPLICABLE: false
+// WITH_RUNTIME
+
+fun withAssign(arg: String?): String {
+    var result: String = ""
+    arg?.let<caret> { result = it }
+    return result
+}

idea/testData/intentions/replaceSingleLineLetIntention/comparisons.kt

@@ -0,0 +1,4 @@
+// IS_APPLICABLE: false
+// WITH_RUNTIME
+
+fun isAlphaOrBeta(str: String) = str.let<caret> { it == "Alpha" || it == "Beta" }

idea/testData/intentions/replaceSingleLineLetIntention/plusNullable.kt

@@ -0,0 +1,4 @@
+// IS_APPLICABLE: false
+// WITH_RUNTIME
+
+fun plusNullable(arg: String?) = arg?.let<caret> { it + "#" } ?: ""

idea/testData/intentions/replaceSingleLineLetIntention/smartCastInBody.kt

@@ -0,0 +1,15 @@
+// IS_APPLICABLE: false
+// WITH_RUNTIME
+
+interface A
+
+interface B : A {
+    val bar: Any?
+}
+
+class Foo {
+    private val a: A = object : A {}
+
+    val isB: Boolean
+        get() = a.let<caret> { it is B && it.bar != null }
+}

idea/testData/intentions/replaceSingleLineLetIntention/typeChecks.kt

@@ -0,0 +1,9 @@
+// IS_APPLICABLE: false
+// WITH_RUNTIME
+
+interface Base
+
+class A : Base
+class B : Base
+
+fun isAB(arg: Base) = arg.let<caret> { it is A || it is B }