From 6746557d05b2b1c207aa5d1a03e5426694c5bf2b Mon Sep 17 00:00:00 2001
From: Mark Harrah <dmharrah@gmail.com>
Date: Mon, 5 Mar 2012 13:40:17 -0500
Subject: [PATCH] addCommandAlias method for defining command aliases in build
 definitions.  fixes #388

---
 main/Defaults.scala                          | 12 ++++++++++++
 sbt/src/sbt-test/actions/add-alias/A.scala   |  3 +++
 sbt/src/sbt-test/actions/add-alias/build.sbt |  2 ++
 sbt/src/sbt-test/actions/add-alias/test      |  2 ++
 4 files changed, 19 insertions(+)
 create mode 100644 sbt/src/sbt-test/actions/add-alias/A.scala
 create mode 100644 sbt/src/sbt-test/actions/add-alias/build.sbt
 create mode 100644 sbt/src/sbt-test/actions/add-alias/test

diff --git a/main/Defaults.scala b/main/Defaults.scala
index fd7e43b73..96cb14550 100644
--- a/main/Defaults.scala
+++ b/main/Defaults.scala
@@ -1139,6 +1139,18 @@ trait BuildExtra extends BuildCommon
 {
 		import Defaults._
 
+	/** Defines an alias given by `name` that expands to `value`.
+	* This alias is defined globally after projects are loaded.
+	* The alias is undefined when projects are unloaded.
+	* Names are restricted to be either alphanumeric or completely symbolic.
+	* As an exception, '-' and '_' are allowed within an alphanumeric name.*/
+	def addCommandAlias(name: String, value: String): Seq[Setting[State => State]] =
+	{
+		val add = (s: State) => BasicCommands.addAlias(s, name, value)
+		val remove = (s: State) => BasicCommands.removeAlias(s, name)
+		def compose(setting: SettingKey[State => State], f: State => State) = setting in Global ~= (_ compose f)
+		Seq( compose(onLoad, add), compose(onUnload, remove) )
+	}
 	def addSbtPlugin(dependency: ModuleID): Setting[Seq[ModuleID]] =
 		libraryDependencies <+= (sbtBinaryVersion in update,scalaBinaryVersion in update) { (sbtV, scalaV) => sbtPluginExtra(dependency, sbtV, scalaV) }
 
diff --git a/sbt/src/sbt-test/actions/add-alias/A.scala b/sbt/src/sbt-test/actions/add-alias/A.scala
new file mode 100644
index 000000000..a5cd1ae25
--- /dev/null
+++ b/sbt/src/sbt-test/actions/add-alias/A.scala
@@ -0,0 +1,3 @@
+object A extends App {
+  if(args(0).toBoolean) () else error("Fail")
+}
diff --git a/sbt/src/sbt-test/actions/add-alias/build.sbt b/sbt/src/sbt-test/actions/add-alias/build.sbt
new file mode 100644
index 000000000..451b72246
--- /dev/null
+++ b/sbt/src/sbt-test/actions/add-alias/build.sbt
@@ -0,0 +1,2 @@
+addCommandAlias("demo-success", "run true") ++
+addCommandAlias("demo-failure", "run false")
diff --git a/sbt/src/sbt-test/actions/add-alias/test b/sbt/src/sbt-test/actions/add-alias/test
new file mode 100644
index 000000000..b82ec3f27
--- /dev/null
+++ b/sbt/src/sbt-test/actions/add-alias/test
@@ -0,0 +1,2 @@
+> demo-success
+-> demo-failure