Fixes scalastyle#16 Custom messages for a rule

Done through the configuration xml, via an element <customMessage>

README.md

@@ -34,7 +34,6 @@ Want to contribute? Great! Look at the wiki for potential rules to implement, or
 6. Create an [Issue](https://github.com/scalastyle/scalastyle/issues) with a link to your branch
 7. Enjoy a coffee and wait
 
-
 Comment filters
 ---------------
 
@@ -49,6 +48,16 @@ You can also switch off checking for a particular rule by specifying the id of t
 	var foobar = 134
 	// scalastyle:on magic.number
 
+Custom messages
+---------------
+
+Messages are defined within the scalastyle_messages.properties. If however, you wish to have a custom error message for a particular rule, then
+you can do so by defining a customMessage element in the configuration, such as:
+
+    <check level="warning" class="org.scalastyle.scalariform.MagicNumberChecker" enabled="true">
+     <customMessage>Please don't use magic numbers</customMessage>
+    </check>
+
 Implemented Rules
 -----------------
 

src/main/scala/org/scalastyle/Checker.scala

@@ -74,7 +74,7 @@ object Checker {
       case None => List[CommentFilter]()
     }
 
-    classes.flatMap(cc => newInstance(cc.className, cc.level, cc.parameters)).map(c => c match {
+    classes.flatMap(cc => newInstance(cc.className, cc.level, cc.parameters, cc.customMessage)).map(c => c match {
       case c: FileChecker => c.verify(file, c.level, lines, lines)
       case c: ScalariformChecker => scalariformAst match {
         case Some(ast) => c.verify(file, c.level, ast.ast, lines)
@@ -93,12 +93,13 @@ object Checker {
     }
   }
 
-  def newInstance(name: String, level: Level, parameters: Map[String, String]): Option[Checker[_]] = {
+  def newInstance(name: String, level: Level, parameters: Map[String, String], customMessage: Option[String]): Option[Checker[_]] = {
     try {
       val clazz = Class.forName(name).asInstanceOf[Class[Checker[_]]]
       val c: Checker[_] = clazz.getConstructor().newInstance().asInstanceOf[Checker[_]]
       c.setParameters(parameters)
       c.setLevel(level)
+      c.setCustomMessage(customMessage)
       Some(c)
     } catch {
       case e: Exception => {
@@ -113,9 +114,11 @@ trait Checker[A] {
   val errorKey: String;
   var parameters = Map[String, String]();
   var level: Level = WarningLevel;
+  var customMessage: Option[String] = None;
 
   def setParameters(parameters: Map[String, String]) = this.parameters = parameters;
   def setLevel(level: Level) = this.level = level;
+  def setCustomMessage(customMessage: Option[String]) = this.customMessage = customMessage
   def getInt(parameter: String, defaultValue: Int) = Integer.parseInt(parameters.getOrElse(parameter, "" + defaultValue))
   def getString(parameter: String, defaultValue: String) = parameters.getOrElse(parameter, defaultValue)
 
@@ -131,10 +134,10 @@ trait Checker[A] {
     }
 
     p2 match {
-      case PositionError(position, args) => StyleError(file, this.getClass(), errorKey, level, args)
-      case FileError(args) => StyleError(file, this.getClass(), errorKey, level, args, None, None)
-      case LineError(line, args) => StyleError(file, this.getClass(), errorKey, level, args, Some(line), None)
-      case ColumnError(line, column, args) => StyleError(file, this.getClass(), errorKey, level, args, Some(line), Some(column))
+      case PositionError(position, args) => StyleError(file, this.getClass(), errorKey, level, args, customMessage = customMessage)
+      case FileError(args) => StyleError(file, this.getClass(), errorKey, level, args, None, None, customMessage)
+      case LineError(line, args) => StyleError(file, this.getClass(), errorKey, level, args, Some(line), None, customMessage)
+      case ColumnError(line, column, args) => StyleError(file, this.getClass(), errorKey, level, args, Some(line), Some(column), customMessage)
     }
   }
 

src/main/scala/org/scalastyle/Message.scala

@@ -63,8 +63,9 @@ case class StartFile[+T <: FileSpec](fileSpec: T) extends Message[T]
 case class EndFile[+T <: FileSpec](fileSpec: T) extends Message[T]
 
 case class StyleError[+T <: FileSpec](fileSpec: T, clazz: Class[_ <: Checker[_]], key: String,
-                                      level: Level, args: List[String], lineNumber: Option[Int] = None, column: Option[Int] = None) extends Message[T] {
-  override def toString() = "StyleError key=" + key + " args=" + args + " lineNumber=" + lineNumber + " column=" + column
+                                      level: Level, args: List[String], lineNumber: Option[Int] = None,
+                                      column: Option[Int] = None, customMessage: Option[String] = None) extends Message[T] {
+  override def toString() = "StyleError key=" + key + " args=" + args + " lineNumber=" + lineNumber + " column=" + column + " customMessage=" + customMessage
 }
 case class StyleException[+T <: FileSpec](fileSpec: T, clazz: Option[Class[_ <: Checker[_]]], message: String,
                                           stacktrace: String, lineNumber: Option[Int] = None, column: Option[Int] = None) extends Message[T]

src/main/scala/org/scalastyle/Output.scala

@@ -17,6 +17,7 @@
 package org.scalastyle
 
 trait Output[T <: FileSpec] {
+  protected[this] val messageHelper = new MessageHelper(this.getClass().getClassLoader())
   private var errors = 0
   private var warnings = 0
   private var files = 0
@@ -31,28 +32,34 @@ trait Output[T <: FileSpec] {
     case EndWork() =>
     case StartFile(file) => files += 1
     case EndFile(file) =>
-    case StyleError(file, clazz, key, level, args, line, column) => level match {
+    case StyleError(file, clazz, key, level, args, line, column, customMessage) => level match {
       case WarningLevel => warnings += 1
       case _ => errors += 1
     }
     case StyleException(file, clazz, message, stacktrace, line, column) => errors += 1
   }
 
+  def findMessage(clazz: Class[_], key: String, args: List[String], customMessage: Option[String]): String = {
+    customMessage match {
+      case Some(s) => s
+      case None => messageHelper.message(clazz.getClassLoader(), key, args)
+    }
+  }
+
   def message(m: Message[T]): Unit
 }
 
 case class OutputResult(files: Int, errors: Int, warnings: Int)
 
 class TextOutput[T <: FileSpec](verbose: Boolean = false, quiet: Boolean = false) extends Output[T] {
-  private val messageHelper = new MessageHelper(getClass().getClassLoader())
   override def message(m: Message[T]) = m match {
     case StartWork() => if (verbose) println("Starting scalastyle")
     case EndWork() =>
     case StartFile(file) => if (verbose) println("start file " + file)
     case EndFile(file) => if (verbose) println("end file " + file)
-    case StyleError(file, clazz, key, level, args, line, column) => {
+    case StyleError(file, clazz, key, level, args, line, column, customMessage) => {
       println(messageHelper.text(level.name) + print("file", file.name) +
-          print("message", messageHelper.message(clazz.getClassLoader(), key, args)) +
+          print("message", findMessage(clazz, key, args, customMessage)) +
           print("line", line) + print("column", column))
     }
     case StyleException(file, clazz, message, stacktrace, line, column) => {

src/main/scala/org/scalastyle/ScalastyleConfiguration.scala

@@ -19,6 +19,7 @@ package org.scalastyle
 import scala.xml.XML
 import scala.xml.Elem;
 import scala.xml.Node;
+import scala.xml.NodeSeq;
 
 object Level {
   def apply(s: String) = s match {
@@ -42,7 +43,7 @@ sealed abstract class ParameterType(val name: String)
 case object IntegerType extends ParameterType("integer")
 case object StringType extends ParameterType("string")
 
-case class ConfigurationChecker(className: String, level: Level, enabled: Boolean, parameters: Map[String, String])
+case class ConfigurationChecker(className: String, level: Level, enabled: Boolean, parameters: Map[String, String], customMessage: Option[String])
 
 object ScalastyleConfiguration {
   def readFromXml(file: String): ScalastyleConfiguration = {
@@ -57,26 +58,37 @@ object ScalastyleConfiguration {
     val className = node.attribute("class").get.text
     val level = Level(node.attribute("level").get.text)
     val enabled = node.attribute("enabled").getOrElse(scala.xml.Text("false")).text.toLowerCase() == "true"
+    val ns = (node \\ "customMessage")
+    val customMessage = if (ns.size == 0) None else (Some(ns(0).text))
 
     ConfigurationChecker(className, level, enabled, (node \\ "parameters" \\ "parameter").map(e => {
       val attributeValue = e.attribute("value")
       val value = if (attributeValue.isDefined) attributeValue.get.text else e.text
       (e.attribute("name").head.text -> value)
-    }).toMap)
+    }).toMap, customMessage)
   }
 
+  private[this] def toCDATA(s: String) = scala.xml.Unparsed("<![CDATA[" + s + "]]>")
+
   def toXml(scalastyleConfiguration: ScalastyleConfiguration): scala.xml.Elem = {
     val elements = scalastyleConfiguration.checks.map(c => {
       val parameters = if (c.parameters.size > 0) {
         val ps = c.parameters.map( p => {
-          val text = scala.xml.Unparsed("<![CDATA[" + p._2 + "]]>")
+          val text = toCDATA(p._2)
           <parameter name={p._1}>{text}</parameter>
         })
         <parameters>{ps}</parameters>
       } else {
         scala.xml.Null
       }
-      <check class={c.className} level={c.level.name} enabled={if (c.enabled) "true" else "false"}>{parameters}</check>
+      val customMessage = c.customMessage match {
+        case Some(s) => {
+          val text = toCDATA(s)
+          <customMessage>{text}</customMessage>
+        }
+        case None => scala.xml.Null
+      }
+      <check class={c.className} level={c.level.name} enabled={if (c.enabled) "true" else "false"}>{customMessage}{parameters}</check>
     })
 
     <scalastyle><name>{scalastyleConfiguration.name}</name>{elements}</scalastyle>

src/test/scala/org/scalastyle/CustomMessageTest.scala

@@ -0,0 +1,47 @@
+// Copyright (C) 2011-2012 the original author or authors.
+// See the LICENCE.txt file distributed with this work for additional
+// information regarding copyright ownership.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package org.scalastyle
+
+// scalastyle:off magic.number
+
+import org.scalatest.junit.AssertionsForJUnit
+import org.junit.Assert.assertEquals
+import org.junit.Assert.assertTrue
+import org.junit.Test
+import _root_.scalariform.lexer.HiddenTokenInfo
+import _root_.scalariform.lexer.Tokens._
+import org.scalastyle.file.CheckerTest
+import org.scalastyle.file.FileLengthChecker
+
+class CustomMessageTest extends CheckerTest {
+  val key = "file.size.limit"
+  val classUnderTest = classOf[FileLengthChecker]
+  val message = Some("custom")
+
+  @Test def testOne() = {
+    val source = """
+package foobar
+
+  object Foobar {
+}
+  object Barbar {
+}
+""";
+
+    assertErrors(List(fileError(List("5"), message)), source, Map("maxFileLength" -> "5"), message)
+  }
+}

src/test/scala/org/scalastyle/file/CheckerTest.scala

@@ -34,11 +34,14 @@ trait CheckerTest {
     def name() = ""
   }
 
-  protected def assertErrors[T <: FileSpec](list: List[Message[T]], source: String, params: Map[String, String] = Map()) = {
-    assertEquals(list, Checker.verifySource(List(ConfigurationChecker(classUnderTest.getName(), WarningLevel, true, params)), NullFileSpec, source))
+  protected def assertErrors[T <: FileSpec](list: List[Message[T]], source: String, params: Map[String, String] = Map(),
+                                            customMessage: Option[String] = None) = {
+    assertEquals(list, Checker.verifySource(List(ConfigurationChecker(classUnderTest.getName(), WarningLevel,
+                                            true, params, customMessage)), NullFileSpec, source))
   }
 
-  protected def fileError(args: List[String] = List()) = StyleError(NullFileSpec, classUnderTest, key, WarningLevel, args, None, None)
+  protected def fileError(args: List[String] = List(), customMessage: Option[String] = None) =
+          StyleError(NullFileSpec, classUnderTest, key, WarningLevel, args, None, None, customMessage)
   protected def lineError(line: Int, args: List[String] = List()) = StyleError(NullFileSpec, classUnderTest, key, WarningLevel, args, Some(line), None)
   protected def columnError(line: Int, column: Int, args: List[String] = List()) =
                 StyleError(NullFileSpec, classUnderTest, key, WarningLevel, args, Some(line), Some(column))