New setting and test: space around arrow inside 'when'

idea/src/org/jetbrains/jet/plugin/formatter/JetCodeStyleSettings.java

@@ -34,6 +34,8 @@ public class JetCodeStyleSettings extends CustomCodeStyleSettings {
     public boolean INSERT_WHITESPACES_IN_SIMPLE_ONE_LINE_METHOD = true;
     public boolean ALIGN_IN_COLUMNS_CASE_BRANCH = false;
 
+    public boolean SPACE_AROUND_WHEN_ARROW = true;
+
     public static JetCodeStyleSettings getInstance(Project project) {
         return CodeStyleSettingsManager.getSettings(project).getCustomSettings(JetCodeStyleSettings.class);
     }

idea/src/org/jetbrains/jet/plugin/formatter/JetFormattingModelBuilder.java

@@ -36,11 +36,11 @@ public class JetFormattingModelBuilder implements FormattingModelBuilder {
     public FormattingModel createModel(PsiElement element, CodeStyleSettings settings) {
         PsiFile containingFile = element.getContainingFile().getViewProvider().getPsi(JetLanguage.INSTANCE);
         JetBlock block = new JetBlock(
-            containingFile.getNode(), ASTAlignmentStrategy.getNullStrategy(), Indent.getNoneIndent(), null, settings,
+                containingFile.getNode(), ASTAlignmentStrategy.getNullStrategy(), Indent.getNoneIndent(), null, settings,
-            createSpacingBuilder(settings));
+                createSpacingBuilder(settings));
 
         return FormattingModelProvider.createFormattingModelForPsiFile(
-            element.getContainingFile(), block, settings);
+                element.getContainingFile(), block, settings);
     }
 
     private static SpacingBuilder createSpacingBuilder(CodeStyleSettings settings) {
@@ -106,7 +106,7 @@ public class JetFormattingModelBuilder implements FormattingModelBuilder {
                 .afterInside(COLON, TYPE_PARAMETER).spaceIf(jetSettings.SPACE_AFTER_EXTEND_COLON)
 
                 .between(VALUE_ARGUMENT_LIST, FUNCTION_LITERAL_EXPRESSION).spaces(1)
-                .aroundInside(ARROW, WHEN_ENTRY).spaces(1)
+                .aroundInside(ARROW, WHEN_ENTRY).spaceIf(jetSettings.SPACE_AROUND_WHEN_ARROW)
                 ;
     }
 

idea/src/org/jetbrains/jet/plugin/formatter/JetLanguageCodeStyleSettingsProvider.java

@@ -123,6 +123,9 @@ public class JetLanguageCodeStyleSettingsProvider extends LanguageCodeStyleSetti
                                           "Insert whitespaces in simple one line methods",
                                           CodeStyleSettingsCustomizable.SPACES_OTHER);
 
+                consumer.showCustomOption(JetCodeStyleSettings.class, "SPACE_AROUND_WHEN_ARROW",
+                                          "Surround arrow in \"when\" clause with spaces",
+                                          CodeStyleSettingsCustomizable.SPACES_OTHER);
                 break;
             case WRAPPING_AND_BRACES_SETTINGS:
                 consumer.showStandardOptions(

idea/testData/formatter/WhenArrow.kt

@@ -0,0 +1,8 @@
+fun f(x: Any): Int {
+    return when (x)  {
+        is Int ->1
+        else->0
+    }
+}
+
+// SET_FALSE: SPACE_AROUND_WHEN_ARROW

idea/testData/formatter/WhenArrow_after.kt

@@ -0,0 +1,8 @@
+fun f(x: Any): Int {
+    return when (x) {
+        is Int->1
+        else->0
+    }
+}
+
+// SET_FALSE: SPACE_AROUND_WHEN_ARROW

idea/testData/formatter/WhenArrow_after_inv.kt

@@ -0,0 +1,8 @@
+fun f(x: Any): Int {
+    return when (x) {
+        is Int -> 1
+        else -> 0
+    }
+}
+
+// SET_FALSE: SPACE_AROUND_WHEN_ARROW

idea/tests/org/jetbrains/jet/formatter/JetFormatterTest.java

@@ -131,6 +131,10 @@ public class JetFormatterTest extends AbstractJetFormatterTest {
         doTest();
     }
 
+    public void testWhenArrow() throws Exception {
+        doTestWithInvert();
+    }
+
     @Override
     public void doTest() throws Exception {
         String originalFileText = AbstractJetFormatterTest.loadFile(getTestName(false) + ".kt");