Add filtering of suggested expressions for postfix templates

Do not suggest qualified expression's selector or a part of user type
because they aren't really independent expressions

idea/src/org/jetbrains/kotlin/idea/codeInsight/postfix/KtPostfixTemplateProvider.kt

@@ -106,7 +106,7 @@ internal fun createExpressionSelector(
 private fun PsiElement.isStatement() = parent is KtBlockExpression
 
 private class KtExpressionPostfixTemplateSelector(
-        val filter: PsiElement.() -> Boolean
+        filter: PsiElement.() -> Boolean
 ) : PostfixTemplateExpressionSelectorBase(Condition(filter)) {
     override fun getNonFilteredExpressions(
             context: PsiElement,
@@ -114,7 +114,11 @@ private class KtExpressionPostfixTemplateSelector(
             offset: Int
     ) = context.parentsWithSelf
             .filterIsInstance<KtExpression>()
-            .takeWhile { it !is KtBlockExpression && it !is KtDeclarationWithBody && !it.isEffectivelyDeclaration() }
+            .takeWhile {
+                it !is KtBlockExpression &&
+                it !is KtDeclarationWithBody &&
+                !it.isEffectivelyDeclaration()
+            }.filter { !it.isSelector && it.parent !is KtUserType }
             .toList()
 }
 
@@ -124,3 +128,6 @@ private fun KtElement.isEffectivelyDeclaration() =
         this !is KtFunctionLiteral &&
         // !(fun (a) = 1)
         (this !is KtNamedFunction || this.name == null)
+
+private val KtExpression.isSelector: Boolean
+    get() = parent is KtQualifiedExpression && (parent as KtQualifiedExpression).selectorExpression == this

idea/testData/codeInsight/postfix/parAfterUserType.kt

@@ -0,0 +1,5 @@
+class A
+fun foo(a: Any) {
+    // Do not suggest 'A' as an expression to parenthesize
+    a as A.par<caret>
+}

idea/testData/codeInsight/postfix/parAfterUserType.kt.after

@@ -0,0 +1,5 @@
+class A
+fun foo(a: Any) {
+    // Do not suggest 'A' as an expression to parenthesize
+    (a as A)
+}

idea/testData/codeInsight/postfix/valAfterReceiver.kt

@@ -0,0 +1,6 @@
+class A {
+    fun bar() = 1
+}
+fun foo(a: A) {
+    val x = a.val<caret>.bar()
+}

idea/testData/codeInsight/postfix/valAfterReceiver.kt.after

@@ -0,0 +1,7 @@
+class A {
+    fun bar() = 1
+}
+fun foo(a: A) {
+    val a1 = a
+    val x = a1.bar()
+}

idea/testData/codeInsight/postfix/valAfterSelector.kt

@@ -0,0 +1,6 @@
+class A {
+    fun bar() = 1
+}
+fun foo(a: A) {
+    val x = a.bar().val<caret>
+}

idea/testData/codeInsight/postfix/valAfterSelector.kt.after

@@ -0,0 +1,7 @@
+class A {
+    fun bar() = 1
+}
+fun foo(a: A) {
+    val bar = a.bar()
+    val x = bar
+}

idea/tests/org/jetbrains/kotlin/idea/codeInsight/postfix/PostfixTemplateProviderTestGenerated.java

@@ -95,6 +95,12 @@ public class PostfixTemplateProviderTestGenerated extends AbstractPostfixTemplat
         doTest(fileName);
     }
 
+    @TestMetadata("parAfterUserType.kt")
+    public void testParAfterUserType() throws Exception {
+        String fileName = KotlinTestUtils.navigationMetadata("idea/testData/codeInsight/postfix/parAfterUserType.kt");
+        doTest(fileName);
+    }
+
     @TestMetadata("return.kt")
     public void testReturn() throws Exception {
         String fileName = KotlinTestUtils.navigationMetadata("idea/testData/codeInsight/postfix/return.kt");
@@ -119,6 +125,18 @@ public class PostfixTemplateProviderTestGenerated extends AbstractPostfixTemplat
         doTest(fileName);
     }
 
+    @TestMetadata("valAfterReceiver.kt")
+    public void testValAfterReceiver() throws Exception {
+        String fileName = KotlinTestUtils.navigationMetadata("idea/testData/codeInsight/postfix/valAfterReceiver.kt");
+        doTest(fileName);
+    }
+
+    @TestMetadata("valAfterSelector.kt")
+    public void testValAfterSelector() throws Exception {
+        String fileName = KotlinTestUtils.navigationMetadata("idea/testData/codeInsight/postfix/valAfterSelector.kt");
+        doTest(fileName);
+    }
+
     @TestMetadata("var.kt")
     public void testVar() throws Exception {
         String fileName = KotlinTestUtils.navigationMetadata("idea/testData/codeInsight/postfix/var.kt");