New setting and test: space around arrow in function types

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_FUNCTION_TYPE_ARROW = true;
+
     public boolean SPACE_AROUND_WHEN_ARROW = true;
 
     public static JetCodeStyleSettings getInstance(Project project) {

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

@@ -110,6 +110,8 @@ public class JetFormattingModelBuilder implements FormattingModelBuilder {
                 //when
                 .aroundInside(ARROW, WHEN_ENTRY).spaceIf(jetSettings.SPACE_AROUND_WHEN_ARROW)
                 .beforeInside(LBRACE, WHEN).spacing(1, 1, 0, true, 0)          //omit blank lines before '{' in 'when' statement
+
+                .aroundInside(ARROW, FUNCTION_TYPE).spaceIf(jetSettings.SPACE_AROUND_FUNCTION_TYPE_ARROW)
                 ;
     }
 

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

@@ -123,6 +123,10 @@ public class JetLanguageCodeStyleSettingsProvider extends LanguageCodeStyleSetti
                                           "Insert whitespaces in simple one line methods",
                                           CodeStyleSettingsCustomizable.SPACES_OTHER);
 
+                consumer.showCustomOption(JetCodeStyleSettings.class, "SPACE_AROUND_FUNCTION_TYPE_ARROW",
+                                          "Surround arrow in function types with spaces",
+                                          CodeStyleSettingsCustomizable.SPACES_OTHER);
+
                 consumer.showCustomOption(JetCodeStyleSettings.class, "SPACE_AROUND_WHEN_ARROW",
                                           "Surround arrow in \"when\" clause with spaces",
                                           CodeStyleSettingsCustomizable.SPACES_OTHER);

idea/testData/formatter/FunctionalType.kt

@@ -0,0 +1,4 @@
+fun test(some: ((Int)->Int) ->Int) {
+}
+
+// SET_TRUE: SPACE_AROUND_FUNCTION_TYPE_ARROW

idea/testData/formatter/FunctionalType_after.kt

@@ -0,0 +1,4 @@
+fun test(some: ((Int) -> Int) -> Int) {
+}
+
+// SET_TRUE: SPACE_AROUND_FUNCTION_TYPE_ARROW

idea/testData/formatter/FunctionalType_after_inv.kt

@@ -0,0 +1,4 @@
+fun test(some: ((Int)->Int)->Int) {
+}
+
+// SET_TRUE: SPACE_AROUND_FUNCTION_TYPE_ARROW

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

@@ -139,6 +139,10 @@ public class JetFormatterTest extends AbstractJetFormatterTest {
         doTest();
     }
 
+    public void testFunctionalType() throws Exception {
+        doTestWithInvert();
+    }
+
     @Override
     public void doTest() throws Exception {
         String originalFileText = AbstractJetFormatterTest.loadFile(getTestName(false) + ".kt");