Do not include partest and it's dependencies in generated pom.

Define custom Ivy configuration that contains all dependencies of
partest (and partest itself) and make sure that this configuration
is not considered when pom is generated.

Remove the comment about significance of dependency order declaration.
Given the fact that we excluded conflicting, transitive dependencies
and all partest dependencies are isolated from regular dependencies
the situation is much better.

Author: gkossakowski

build.sbt

@@ -83,12 +83,39 @@ TestKeys.includeTestDependencies := true
 
 libraryDependencies ++= Seq("junit" % "junit" % "4.11" % "test", "com.novocode" % "junit-interface" % "0.10" % "test")
 
+// Define custom Ivy configuration called "partest". Ivy configuration is analogous to Maven scope
+// and allows to group dependencies together, see:
+// http://www.scala-sbt.org/release/docs/Detailed-Topics/Library-Management#configurations
+// We define custom configuration so we can resolve partest through Ivy from Maven repository.
+// However, by putting partest dependency in custom configuration we can make sure that
+// it doesn't interfere with any other dependencies. Also, we can make sure that dependencies
+// resolved in partest configuration NOT included in generated pom. See makePomConfiguration
+// setting we define below.
+val partestConfiguration = config("partest")
+
+// Define configuration to be used to assemble the classpath for compiling and running
+// tests. We define it as an union of default test configuration (scope in Maven's speak)
+// and partest configuration.
+val testWithPartestConfiguration = Configurations.Test.extend(partestConfiguration)
+
+// register both configurations we defined so they are processed by `update` command
+ivyConfigurations ++= Seq(partestConfiguration, testWithPartestConfiguration)
+
+// override configuration used to assemble classpath for tests
+configuration in Test := testWithPartestConfiguration
+
+// Define configurations (scopes in Maven's speak) that are taken into account when
+// generating pom. By default sbt sets MakePomConfiguration.configurations to None which is
+// interpreted as "include dependencies in all configurations". That would include
+// dependencies in partest configuration which is not what we want: see comment above
+// where we define the partest configuration.
+makePomConfiguration := makePomConfiguration.value.copy(configurations = Some(Configurations.default))
+
 // default
 TestKeys.partestVersion := "1.0.0-RC6"
 
 // the actual partest the interface calls into -- must be binary version close enough to ours
 // so that it can link to the compiler/lib we're using (testing)
-// NOTE: not sure why, but the order matters (maybe due to the binary version conflicts for xml/parser combinators pulled in for scaladoc?)
 libraryDependencies ++= (
   if (TestKeys.includeTestDependencies.value) {
     /**
@@ -111,8 +138,8 @@ libraryDependencies ++= (
       dep.exclude("org.scala-lang.modules", "scala-xml_2.11.0-M5").
       exclude("org.scala-lang.modules", "scala-xml_2.11.0-M4").
       exclude("org.scalacheck", "scalacheck_2.11.0-M5")
-    Seq("org.scala-lang.modules" % "scala-partest-interface_2.11.0-M5" % "0.2"                         % "test",
-        "org.scala-lang.modules" % "scala-partest_2.11.0-M5"           % TestKeys.partestVersion.value % "test").
+    Seq("org.scala-lang.modules" % "scala-partest-interface_2.11.0-M5" % "0.2"                         % "partest",
+        "org.scala-lang.modules" % "scala-partest_2.11.0-M5"           % TestKeys.partestVersion.value % "partest").
       map(excludeScalaXml)
   }
   else Seq.empty