Merge pull request #308 from cvogt/assert-right-build-class

Assert right build class. Fixes #174

4 files changed, 17 insertions, 2 deletions

diff --git a/examples/wartremover-example/build/build.scala b/examples/wartremover-example/build/build.scala
index c715f20..7510f91 100644
--- a/examples/wartremover-example/build/build.scala
+++ b/examples/wartremover-example/build/build.scala
@@ -3,7 +3,7 @@ import cbt._
 import org.wartremover.warts.{ Null, Var }
 import org.wartremover.WartTraverser
 
-class Build(val context: Context) extends BuildBuild with WartRemover {
+class Build(val context: Context) extends BaseBuild with WartRemover {
 
   override def wartremoverErrors: Seq[WartTraverser] = Seq(Var, Null)
 }
diff --git a/stage1/cbt.scala b/stage1/cbt.scala
index bf82556..6aa73f9 100644
--- a/stage1/cbt.scala
+++ b/stage1/cbt.scala
@@ -8,6 +8,7 @@ object `package`{
   implicit class TypeInferenceSafeEquals[T](value: T){
     /** if you don't manually upcast, this will catch comparing different types */
     def ===(other: T) = value == other
+    def =!=(other: T) = value != other // =!= instead of !==, because it has better precedence
   }
 
   val mavenCentral = new URL("https://repo1.maven.org/maven2")
diff --git a/stage2/BasicBuild.scala b/stage2/BasicBuild.scala
index d8d1b8b..3ce9ed1 100644
--- a/stage2/BasicBuild.scala
+++ b/stage2/BasicBuild.scala
@@ -18,8 +18,17 @@ trait BaseBuild extends BuildInterface with DependencyImplementation with Trigge
   def enableConcurrency = false
   final def projectDirectory: File = lib.realpath(context.projectDirectory)
   assert( projectDirectory.exists, "projectDirectory does not exist: " ++ projectDirectory.string )
+  assert(
+    projectDirectory.getName =!= "build" ||
+    {
+      def transitiveInterfaces(cls: Class[_]): Vector[Class[_]] = cls.getInterfaces.toVector.flatMap(i => i +: transitiveInterfaces(i))
+      transitiveInterfaces(this.getClass).contains(classOf[BuildBuildWithoutEssentials])
+    },
+    "You need to extend BuildBuild in: " + projectDirectory + "/build"
+  )
+
   final def usage: String = lib.usage(this.getClass, show)
-  
+
   final def taskNames: String = lib.taskNames(this.getClass).sorted.mkString("\n")
 
   // ========== meta data ==========
diff --git a/stage2/BuildBuild.scala b/stage2/BuildBuild.scala
index 5eb7622..0736e7e 100644
--- a/stage2/BuildBuild.scala
+++ b/stage2/BuildBuild.scala
@@ -6,6 +6,11 @@ trait BuildBuild extends BuildBuildWithoutEssentials{
     super.dependencies :+ plugins.essentials
 }
 trait BuildBuildWithoutEssentials extends BaseBuild{
+  assert(
+    projectDirectory.getName === "build",
+    "You can't extend BuildBuild in: " + projectDirectory + "/build"
+  )
+
   protected final val managedContext = context.copy(
     projectDirectory = managedBuildDirectory,
     parentBuild=Some(this)