KT-2242 formatting problems: function literal passed outside the parentheses - option for spaces in single line function literal

#KT-2242 Fixed

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

@@ -143,8 +143,13 @@ public class JetBlock extends AbstractBlock {
         IElementType child1Type = ((ASTBlock) child1).getNode().getElementType();
         IElementType child2Type = ((ASTBlock) child2).getNode().getElementType();
 
+        JetCodeStyleSettings jetSettings = mySettings.getCustomSettings(JetCodeStyleSettings.class);
+        int spacesInSimpleMethod = jetSettings.INSERT_WHITESPACES_IN_SIMPLE_ONE_LINE_METHOD ? 1 : 0;
+
         if (parentType == FUNCTION_LITERAL && child1Type == LBRACE && child2Type == BLOCK) {
-            return Spacing.createDependentLFSpacing(1, 1, this.getTextRange(), mySettings.KEEP_LINE_BREAKS, mySettings.KEEP_BLANK_LINES_IN_CODE);
+            return Spacing.createDependentLFSpacing(
+                    spacesInSimpleMethod, spacesInSimpleMethod, this.getTextRange(),
+                    mySettings.KEEP_LINE_BREAKS, mySettings.KEEP_BLANK_LINES_IN_CODE);
         }
 
         if (parentType == FUNCTION_LITERAL && child1Type == ARROW && child2Type == BLOCK) {
@@ -152,11 +157,14 @@ public class JetBlock extends AbstractBlock {
         }
 
         if (parentType == FUNCTION_LITERAL && child2Type == RBRACE) {
-            return Spacing.createDependentLFSpacing(1, 1, this.getTextRange(), mySettings.KEEP_LINE_BREAKS, mySettings.KEEP_BLANK_LINES_IN_CODE);
+            return Spacing.createDependentLFSpacing(
+                    spacesInSimpleMethod, spacesInSimpleMethod, this.getTextRange(),
+                    mySettings.KEEP_LINE_BREAKS, mySettings.KEEP_BLANK_LINES_IN_CODE);
         }
 
         if (parentType == FUNCTION_LITERAL && child1Type == LBRACE) {
-            return Spacing.createSpacing(1, 1, 0, mySettings.KEEP_LINE_BREAKS, mySettings.KEEP_BLANK_LINES_IN_CODE);
+            return Spacing.createSpacing(spacesInSimpleMethod, spacesInSimpleMethod, 0,
+                                         mySettings.KEEP_LINE_BREAKS, mySettings.KEEP_BLANK_LINES_IN_CODE);
         }
 
         return null;

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

@@ -31,6 +31,8 @@ public class JetCodeStyleSettings extends CustomCodeStyleSettings {
     public boolean SPACE_BEFORE_EXTEND_COLON = false;
     public boolean SPACE_AFTER_EXTEND_COLON = true;
 
+    public boolean INSERT_WHITESPACES_IN_SIMPLE_ONE_LINE_METHOD = true;
+
     public static JetCodeStyleSettings getInstance(Project project) {
         return CodeStyleSettingsManager.getSettings(project).getCustomSettings(JetCodeStyleSettings.class);
     }

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

@@ -52,10 +52,12 @@ public class JetLanguageCodeStyleSettingsProvider extends LanguageCodeStyleSetti
                         "                14\n" +
                         "        )\n" +
                         "    }\n" +
+                        "    private val f = {(a: Int)->a*2}\n" +
                         "}";
             default:
                 return
                         "class Some {\n" +
+                        "  private val f = {(a: Int)->a*2}\n" +
                         "  fun foo() : Int {\n" +
                         "    val test : Int = 12\n" +
                         "    return test\n" +
@@ -104,6 +106,11 @@ public class JetLanguageCodeStyleSettingsProvider extends LanguageCodeStyleSetti
                 consumer.showCustomOption(JetCodeStyleSettings.class, "SPACE_BEFORE_EXTEND_COLON",
                                           "Space before colon in new type definition",
                                           CodeStyleSettingsCustomizable.SPACES_OTHER);
+
+                consumer.showCustomOption(JetCodeStyleSettings.class, "INSERT_WHITESPACES_IN_SIMPLE_ONE_LINE_METHOD",
+                                          "Insert whitespaces in simple one line methods",
+                                          CodeStyleSettingsCustomizable.SPACES_OTHER);
+
                 break;
             case WRAPPING_AND_BRACES_SETTINGS:
                 consumer.showStandardOptions(

idea/testData/formatter/MultilineFunctionLiteralWithParams.kt

@@ -1,4 +1,6 @@
 fun test(some: (Int) -> Int) {
 }
 
-fun foo() = test() {a -> if (true) { a } else { 1 }}
+fun foo() = test() {a -> if (true) { a } else { 1 }}
+
+// SET_TRUE: INSERT_WHITESPACES_IN_SIMPLE_ONE_LINE_METHOD

idea/testData/formatter/MultilineFunctionLiteralWithParams_after.kt

@@ -7,4 +7,6 @@ fun foo() = test() { a ->
     } else {
         1
     }
-}
+}
+
+// SET_TRUE: INSERT_WHITESPACES_IN_SIMPLE_ONE_LINE_METHOD

idea/testData/formatter/MultilineFunctionLiteralWithParams_after_inv.kt

@@ -0,0 +1,12 @@
+fun test(some: (Int) -> Int) {
+}
+
+fun foo() = test() {a ->
+    if (true) {
+        a
+    } else {
+        1
+    }
+}
+
+// SET_TRUE: INSERT_WHITESPACES_IN_SIMPLE_ONE_LINE_METHOD

idea/testData/formatter/SingleLineFunctionLiteral.kt

@@ -1,4 +1,6 @@
 fun test(some: (Int) -> Int) {
 }
 
-fun foo() = test() { it }
+fun foo() = test() { it }
+
+// SET_TRUE: INSERT_WHITESPACES_IN_SIMPLE_ONE_LINE_METHOD

idea/testData/formatter/SingleLineFunctionLiteral_after.kt

@@ -1,4 +1,6 @@
 fun test(some: (Int) -> Int) {
 }
 
-fun foo() = test() { it }
+fun foo() = test() { it }
+
+// SET_TRUE: INSERT_WHITESPACES_IN_SIMPLE_ONE_LINE_METHOD

idea/testData/formatter/SingleLineFunctionLiteral_after_inv.kt

@@ -0,0 +1,6 @@
+fun test(some: (Int) -> Int) {
+}
+
+fun foo() = test() {it}
+
+// SET_TRUE: INSERT_WHITESPACES_IN_SIMPLE_ONE_LINE_METHOD

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

@@ -73,7 +73,7 @@ public class JetFormatterTest extends AbstractJetFormatterTest {
     }
 
     public void testMultilineFunctionLiteralWithParams() throws Exception {
-        doTest();
+        doTestWithInvert();
     }
 
     public void testParameters() throws Exception {
@@ -93,7 +93,7 @@ public class JetFormatterTest extends AbstractJetFormatterTest {
     }
 
     public void testSingleLineFunctionLiteral() throws Exception {
-        doTest();
+        doTestWithInvert();
     }
 
     public void testSpaceAroundExtendColon() throws Exception {