fixed another edge case with call by name params

Author: Daniel Trinh

scalariform/src/main/scala/scalariform/formatter/ExprFormatter.scala

@@ -938,6 +938,8 @@ trait ExprFormatter { self: HasFormattingPreferences with AnnotationFormatter wi
       TextEditProcessor.runEdits(source, edits)
     }
 
+    // TODO: is there a less brittle way of calculating the extra '+ 1' character
+    // spaces besides guessing?
     def calculateLengths: ParamSectionLengths = {
 
       def calculatePrefixLength: Int = {
@@ -976,21 +978,27 @@ trait ExprFormatter { self: HasFormattingPreferences with AnnotationFormatter wi
         // Calculate longest "type" length.
         var typeLength = 0
         for ((_, typeAst) ← paramTypeOpt) {
-          typeAst.tokens.foreach { token ⇒
+          val firstTypeToken :: otherTypeTokens = typeAst.tokens
+
+          // Add one to count, accounting for spaces in call by name params, (ex: => String)
+          if (firstTypeToken.tokenType == ARROW)
+            typeLength += 1
+
+          typeLength += firstTypeToken.length
+
+          otherTypeTokens.foreach { token ⇒
 
             // Add two to count, accounting for spaces between brackets, (ex: Option[ String ])
             if (spacesInsideBrackets && token.tokenType == RBRACKET)
               typeLength += 2
 
             // Add two to count, accounting for spaces in function types, (ex: Int => String)
-            if (token.tokenType == ARROW) {
+            if (token.tokenType == ARROW)
               typeLength += 2
-            }
 
             // Add one to count, accounting for spaces after commas, (ex: Map[Int, String])
-            if (token.tokenType == COMMA) {
+            if (token.tokenType == COMMA)
               typeLength += 1
-            }
 
             typeLength += token.length
           }

scalariform/src/main/scala/scalariform/lexer/Tokens.scala

@@ -114,5 +114,4 @@ object Tokens {
 
   val LITERALS = Set(CHARACTER_LITERAL, INTEGER_LITERAL, FLOATING_POINT_LITERAL, STRING_LITERAL, STRING_PART, SYMBOL_LITERAL, TRUE, FALSE, NULL)
 
-}
-
+}

scalariform/src/test/scala/scalariform/formatter/TemplateFormatterTest.scala

@@ -414,14 +414,22 @@ implicit val formattingPreferences = FormattingPreferences.setPreference(SpacesW
       |  f:             HttpCrawlerClient => T,
       |  port:          Int                    = SpecHelper.port): T"""
 
+    // By name parameters have correct spacing
+    """def a(
+      |  p1: => (SomeLongByNameParam => SomeShorterParam) = Null,
+      |  param2: SomeShorterParam = Null): A""" ==>
+   """def a(
+      |  p1:     => (SomeLongByNameParam => SomeShorterParam) = Null,
+      |  param2: SomeShorterParam                             = Null): A"""
+
     // Formats parameterized types correctly
     """def A(complicatedType: Option[B  ,C,      D[E, F,G]] = None,
       | simpleType: String = ""): B""" ==>
     """def A(complicatedType: Option[B, C, D[E, F, G]] = None,
       |      simpleType:      String                   = ""): B"""
 
 
-  // Param gets placed onto a new line due to current limitations of existing IntertokenFormatInstructions
+    // Param gets placed onto a new line due to current limitations of existing IntertokenFormatInstructions
     """case class Spacing(param: Int = 1,
       |paramTwo: Int = 2,
       |paramThree: String = "3")""" ==>