Format spaces in cast expression (KT-12035)

#KT-12035 Fixed

ChangeLog.md

@@ -42,6 +42,7 @@ Issues fixed:
 - [KT-11512](https://youtrack.jetbrains.com/issue/KT-11512) Allow choosing any source root in "Move file to directory" intention
 - [KT-10950](https://youtrack.jetbrains.com/issue/KT-10950) Keep original file package name when moving top-level declarations to separate file (provided it's not ambiguous)
 - [KT-10174](https://youtrack.jetbrains.com/issue/KT-10174) Optimize imports after applying "Move declaration to separate file" intention
+- [KT-12035](https://youtrack.jetbrains.com/issue/KT-12035) Auto-format cast expressions
 
 #### Debugger
 

idea/formatter/src/org/jetbrains/kotlin/idea/formatter/kotlinSpacingRules.kt

@@ -164,6 +164,8 @@ fun createSpacingBuilder(settings: CodeStyleSettings, builderUtil: KotlinSpacing
             betweenInside(DOT, IDENTIFIER, FUN).spacing(0, 0, 0, false, 0)
             afterInside(IDENTIFIER, FUN).spacing(0, 0, 0, false, 0)
 
+            around(AS_KEYWORD).spaces(1)
+
             // before LPAR in constructor(): this() {}
             after(CONSTRUCTOR_DELEGATION_REFERENCE).spacing(0, 0, 0, false, 0)
 

idea/testData/formatter/Cast.after.kt

@@ -0,0 +1,3 @@
+fun foo() {
+    val a = 1 as Int
+}

idea/testData/formatter/Cast.kt

@@ -0,0 +1,3 @@
+fun foo() {
+    val a = 1  as  Int
+}

idea/tests/org/jetbrains/kotlin/formatter/FormatterTestGenerated.java

@@ -91,6 +91,12 @@ public class FormatterTestGenerated extends AbstractFormatterTest {
             doTest(fileName);
         }
 
+        @TestMetadata("Cast.after.kt")
+        public void testCast() throws Exception {
+            String fileName = KotlinTestUtils.navigationMetadata("idea/testData/formatter/Cast.after.kt");
+            doTest(fileName);
+        }
+
         @TestMetadata("CatchFinallyOnNewLine.after.kt")
         public void testCatchFinallyOnNewLine() throws Exception {
             String fileName = KotlinTestUtils.navigationMetadata("idea/testData/formatter/CatchFinallyOnNewLine.after.kt");