From f186d50dafbb0a0311103ed5f697e4f70e1a913a Mon Sep 17 00:00:00 2001
From: Mark Harrah <dmharrah@gmail.com>
Date: Thu, 10 Dec 2009 21:04:51 -0500
Subject: [PATCH] Improving launcher error handling...

---
 launch/Boot.scala                | 8 ++++----
 launch/Create.scala              | 6 +++---
 launch/Exceptions.scala          | 6 ++++++
 launch/LaunchConfiguration.scala | 6 +-----
 launch/Pre.scala                 | 4 +++-
 5 files changed, 17 insertions(+), 13 deletions(-)
 create mode 100644 launch/Exceptions.scala

diff --git a/launch/Boot.scala b/launch/Boot.scala
index 2cc17d56b..81bba43d7 100644
--- a/launch/Boot.scala
+++ b/launch/Boot.scala
@@ -15,16 +15,16 @@ object Boot
 		try { Launch(args.toList) }
 		catch
 		{
-			case b: BootException => errorAndExit(b)
+			case b: BootException => errorAndExit(b.toString)
 			case e =>
 				e.printStackTrace
-				errorAndExit(e)
+				errorAndExit(Pre.prefixError(e.toString))
 		}
 		System.exit(0)
 	}
-	private def errorAndExit(e: Throwable)
+	private def errorAndExit(msg: String)
 	{
-		System.out.println("Error during sbt execution: " + e.toString)
+		System.out.println(msg)
 		System.exit(1)
 	}
 }
diff --git a/launch/Create.scala b/launch/Create.scala
index 61ff779c9..20f644818 100644
--- a/launch/Create.scala
+++ b/launch/Create.scala
@@ -10,12 +10,12 @@ object Initialize
 	{
 		SimpleReader.readLine(promptCreate + " (y/N" + (if(enableQuick) "/s" else "") + ") ") match
 		{
-			case None => error("")
+			case None => declined("")
 			case Some(line) =>
 				line.toLowerCase match
 				{
 					case "y" | "yes" => process(file, spec, _.create)
-					case "n" | "no" | "" => error("")
+					case "n" | "no" | "" => declined("")
 					case "s" => process(file, spec, _.quick)
 				}
 		}
@@ -41,7 +41,7 @@ object Initialize
 		{
 			case set: SetProperty => properties.setProperty(name, set.value)
 			case prompt: PromptProperty =>
-				def noValue = error("No value provided for " + prompt.label)
+				def noValue = declined("No value provided for " + prompt.label)
 				SimpleReader.readLine(prompt.label + prompt.default.toList.map(" [" + _ + "]").mkString + ": ") match
 				{
 					case None => noValue
diff --git a/launch/Exceptions.scala b/launch/Exceptions.scala
new file mode 100644
index 000000000..7ceca5d5b
--- /dev/null
+++ b/launch/Exceptions.scala
@@ -0,0 +1,6 @@
+package xsbt.boot
+
+// The exception to use when an error occurs at the launcher level (and not a nested exception).
+// This indicates overrides toString because the exception class name is not needed to understand
+// the error message.
+class BootException(override val toString: String) extends RuntimeException(toString)
diff --git a/launch/LaunchConfiguration.scala b/launch/LaunchConfiguration.scala
index fbfc77297..0b3236048 100644
--- a/launch/LaunchConfiguration.scala
+++ b/launch/LaunchConfiguration.scala
@@ -100,8 +100,4 @@ object LogLevel extends Enumeration
 	def apply(s: String): Logging = new Logging(toValue(s))
 }
 
-final class AppConfiguration(val arguments: Array[String], val baseDirectory: File, val provider: xsbti.AppProvider) extends xsbti.AppConfiguration
-// The exception to use when an error occurs at the launcher level (and not a nested exception).
-// This indicates overrides toString because the exception class name is not needed to understand
-// the error message.
-class BootException(override val toString: String) extends RuntimeException
\ No newline at end of file
+final class AppConfiguration(val arguments: Array[String], val baseDirectory: File, val provider: xsbti.AppProvider) extends xsbti.AppConfiguration
\ No newline at end of file
diff --git a/launch/Pre.scala b/launch/Pre.scala
index 703bf109c..11ca3d856 100644
--- a/launch/Pre.scala
+++ b/launch/Pre.scala
@@ -12,7 +12,9 @@ object Pre
 	def assert(condition: Boolean, msg: => String): Unit = if (!condition) throw new AssertionError(msg)
 	def assert(condition: Boolean): Unit = assert(condition, "Assertion failed")
 	def require(condition: Boolean, msg: => String): Unit = if (!condition) throw new IllegalArgumentException(msg)
-	def error(msg: String): Nothing = throw new BootException(msg)
+	def error(msg: String): Nothing = throw new BootException(prefixError(msg))
+	def declined(msg: String): Nothing = throw new BootException(msg)
+	def prefixError(msg: String): String = "Error during sbt execution: " + msg
 	def toBoolean(s: String) = java.lang.Boolean.parseBoolean(s)
 	def toArray[T](list: List[T]) =
 	{