Merge pull request scalastyle#176 from er1c/ignorewhitespacelines

Add an option to ignore reporting on entire lines that are whitespace…
matthewfarwell · Jun 15, 2016 · ebf397d · ebf397d
2 parents 917a06e + 5d2585d
commit ebf397d
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Showing 9 changed files with 88 additions and 27 deletions.
diff --git a/lib/scalastyle_config.xml b/lib/scalastyle_config.xml
@@ -26,7 +26,11 @@
   </parameters>
  </check>
  <check class="org.scalastyle.scalariform.SpacesAfterPlusChecker" level="warning" enabled="true"></check>
- <check class="org.scalastyle.file.WhitespaceEndOfLineChecker" level="warning" enabled="true"></check>
+ <check class="org.scalastyle.file.WhitespaceEndOfLineChecker" level="warning" enabled="true">
+   <parameters>
+    <parameter name="ignoreWhitespaceLines"><![CDATA[false]]></parameter>
+   </parameters>
+ </check>
  <check class="org.scalastyle.scalariform.SpacesBeforePlusChecker" level="warning" enabled="true"></check>
  <check class="org.scalastyle.file.FileLineLengthChecker" level="warning" enabled="true">
   <parameters>

diff --git a/lib/scalastyle_scala_config.xml b/lib/scalastyle_scala_config.xml
@@ -26,7 +26,9 @@
   </parameters>
  </check>
  <check level="warning" class="org.scalastyle.scalariform.SpacesAfterPlusChecker" enabled="false"></check>
- <check level="warning" class="org.scalastyle.file.WhitespaceEndOfLineChecker" enabled="false"></check>
+ <check level="warning" class="org.scalastyle.file.WhitespaceEndOfLineChecker" enabled="false">
+   <parameter name="ignoreWhitespaceLines"><![CDATA[false]]></parameter>
+ </check>
  <check level="warning" class="org.scalastyle.scalariform.SpacesBeforePlusChecker" enabled="false"></check>
  <check level="warning" class="org.scalastyle.file.FileLineLengthChecker" enabled="true">
   <parameters>

diff --git a/src/main/resources/default_config.xml b/src/main/resources/default_config.xml
@@ -26,7 +26,11 @@
   </parameters>
  </check>
  <check level="warning" class="org.scalastyle.scalariform.SpacesAfterPlusChecker" enabled="true"></check>
- <check level="warning" class="org.scalastyle.file.WhitespaceEndOfLineChecker" enabled="true"></check>
+ <check level="warning" class="org.scalastyle.file.WhitespaceEndOfLineChecker" enabled="true">
+   <parameters>
+    <parameter name="ignoreWhitespaceLines"><![CDATA[false]]></parameter>
+   </parameters>
+ </check>
  <check level="warning" class="org.scalastyle.scalariform.SpacesBeforePlusChecker" enabled="true"></check>
  <check level="warning" class="org.scalastyle.file.FileLineLengthChecker" enabled="true">
   <parameters>

diff --git a/src/main/resources/reference.conf b/src/main/resources/reference.conf
@@ -41,6 +41,9 @@ spaces.after.plus.description = "Check that the plus sign is followed by a space
 whitespace.end.of.line.message = "Whitespace at end of line"
 whitespace.end.of.line.label = "Whitespace at end of line"
 whitespace.end.of.line.description = "Check that there is no trailing whitespace at the end of lines"
+whitespace.end.of.line.ignoreWhitespaceLines.label = "Ignore lines with just whitespace"
+whitespace.end.of.line.ignoreWhitespaceLines.description = "Skip a line if the entire contents are whitespace characters"
+
 
 spaces.before.plus.message = "There should be a space before the plus (+) sign"
 spaces.before.plus.label = "Space before plus"

diff --git a/src/main/resources/scalastyle_definition.xml b/src/main/resources/scalastyle_definition.xml
@@ -1,7 +1,7 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <!--  scalastyle definition file. This contains the list of checkers and the parameters & types available -->
 <scalastyle-definition>
-	<checker class="org.scalastyle.file.FileTabChecker" id="line.contains.tab" defaultLevel="warning"/>
+    <checker class="org.scalastyle.file.FileTabChecker" id="line.contains.tab" defaultLevel="warning"/>
     <checker class="org.scalastyle.file.FileLengthChecker" id="file.size.limit" defaultLevel="warning">
         <parameters>
             <parameter name="maxFileLength" type="integer" default="1500"/>
@@ -13,15 +13,19 @@
         </parameters>
     </checker>
     <checker class="org.scalastyle.scalariform.SpacesAfterPlusChecker" id="spaces.after.plus" defaultLevel="warning" />
-    <checker class="org.scalastyle.file.WhitespaceEndOfLineChecker" id="whitespace.end.of.line" defaultLevel="warning" />
+    <checker class="org.scalastyle.file.WhitespaceEndOfLineChecker" id="whitespace.end.of.line" defaultLevel="warning">
+        <parameters>
+            <parameter name="ignoreWhitespaceLines" type="boolean" default="false" />
+        </parameters>
+    </checker>
     <checker class="org.scalastyle.scalariform.SpacesBeforePlusChecker" id="spaces.before.plus" defaultLevel="warning" />
-	<checker class="org.scalastyle.file.FileLineLengthChecker" id="line.size.limit" defaultLevel="warning" >
-		<parameters>
+    <checker class="org.scalastyle.file.FileLineLengthChecker" id="line.size.limit" defaultLevel="warning" >
+        <parameters>
             <parameter name="maxLineLength" type="integer" default="160" />
             <parameter name="tabSize" type="integer" default="4" />
             <parameter name="ignoreImports" type="boolean" default="false" />
-		</parameters>
-	</checker>
+        </parameters>
+    </checker>
     <checker class="org.scalastyle.scalariform.ClassNamesChecker" id="class.name" defaultLevel="warning">
         <parameters>
             <parameter name="regex" type="string" default="^[A-Z][A-Za-z]*$" />

diff --git a/src/main/resources/scalastyle_documentation.xml b/src/main/resources/scalastyle_documentation.xml
@@ -733,7 +733,11 @@ To bring consistency with how comments should be formatted, leave a space right
  </justification>
  <example-configuration>
  <![CDATA[
-    <check level="warning" class="org.scalastyle.file.WhitespaceEndOfLineChecker" enabled="true" />
+    <check level="warning" class="org.scalastyle.file.WhitespaceEndOfLineChecker" enabled="true">
+     <parameters>
+      <parameter name="ignoreWhitespaceLines" type="boolean" default="false" />
+     </parameters>
+    </check>
  ]]>
  </example-configuration>
  </check>

diff --git a/src/main/scala/org/scalastyle/file/WhitespaceEndOfLineChecker.scala b/src/main/scala/org/scalastyle/file/WhitespaceEndOfLineChecker.scala
@@ -25,33 +25,38 @@ import org.scalastyle.ScalastyleError
 
 class WhitespaceEndOfLineChecker extends FileChecker {
   val errorKey = "whitespace.end.of.line"
+  lazy val ignoreWhitespaceLines = getBoolean("ignoreWhitespaceLines", false)
 
   private val whitespaces = Set(' ', '\t')
   private val endOfLines = Set('\n', '\r')
 
-  private def endsWithWhitespace(s: String) = {
+  private def endsWithWhitespace(s: String): (Boolean, Int) = {
     val sb = s.reverse
 
-    var endOfLinesIndex = 0;
-    while (endOfLinesIndex < sb.length() && endOfLines(sb(endOfLinesIndex))) {
-      endOfLinesIndex += 1
-    }
-
-    var whitespaceIndex = endOfLinesIndex;
-    while (whitespaceIndex < sb.length() && whitespaces(sb(whitespaceIndex))) {
-      whitespaceIndex += 1
-    }
-
-    (whitespaceIndex != endOfLinesIndex, s.length() - whitespaceIndex)
+    (for {
+      withoutEndOfLines <- Some(sb.zipWithIndex.dropWhile{ case (c: Char, idx: Int) => endOfLines.contains(c) })
+      (nextChar, eolIndex) <- withoutEndOfLines.headOption
+      if (whitespaces.contains(nextChar))
+    } yield {
+      withoutEndOfLines.dropWhile{ case (c: Char, idx: Int) =>
+        whitespaces.contains(c)
+      }.headOption.map{ case (c: Char, idx: Int) =>
+        (true, s.length() - idx)
+      }.getOrElse {
+        if (ignoreWhitespaceLines) (false, 0)
+        else (true, 0)
+      }
+    } ).getOrElse( (false, 0) )
   }
 
   def verify(lines: Lines): List[ScalastyleError] = {
     val errors = for {
-      line <- lines.lines.zipWithIndex;
-      whitespace = endsWithWhitespace(line._1.text)
-      if (whitespace._1)
+      (line, lineIndex) <- lines.lines.zipWithIndex
+      (hasWhitespace, whitespaceIndex) = endsWithWhitespace(line.text)
+      if (hasWhitespace)
+      if (!ignoreWhitespaceLines || line.text.trim.size > 0)
     } yield {
-      ColumnError(line._2 + 1, whitespace._2)
+      ColumnError(lineIndex + 1, whitespaceIndex)
     }
 
     errors.toList

diff --git a/src/test/resources/config/scalastyle_config.xml b/src/test/resources/config/scalastyle_config.xml
@@ -26,7 +26,11 @@
   </parameters>
  </check>
  <check level="warning" class="org.scalastyle.scalariform.SpacesAfterPlusChecker" enabled="true"></check>
- <check level="warning" class="org.scalastyle.file.WhitespaceEndOfLineChecker" enabled="true"></check>
+ <check level="warning" class="org.scalastyle.file.WhitespaceEndOfLineChecker" enabled="true">
+   <parameters>
+    <parameter name="ignoreWhitespaceLines"><![CDATA[false]]></parameter>
+   </parameters>
+ </check>
  <check level="warning" class="org.scalastyle.scalariform.SpacesBeforePlusChecker" enabled="true"></check>
  <check level="warning" class="org.scalastyle.file.FileLineLengthChecker" enabled="true">
   <parameters>

diff --git a/src/test/scala/org/scalastyle/file/WhitespaceEndOfLineCheckerTest.scala b/src/test/scala/org/scalastyle/file/WhitespaceEndOfLineCheckerTest.scala
@@ -65,4 +65,35 @@ object Foobar {
 
     assertErrors(List(columnError(2, 14), columnError(3, 13)), source)
   }
+
+  @Test def testThree(): Unit = {
+    val source = s"""
+package foobar
+
+  object Foobar {
+    val foo = "foo"
+~~
+    val bar = "bar"
+##
+  }
+""".replaceAll("~", " ").replaceAll("#", "\t");
+
+    assertErrors(List(), source, Map("ignoreWhitespaceLines" -> "true"))
+  }
+
+  @Test def testFour(): Unit = {
+    val source =
+      s"""
+package foobar
+
+  object Foobar {
+    val foo = "foo"
+~~
+    val bar = "bar"
+##
+  }
+""".replaceAll("~", " ").replaceAll("#", "\t");
+
+    assertErrors(List(columnError(6, 0), columnError(8, 0)), source, Map("ignoreWhitespaceLines" -> "false"))
+  }
 }