add example showing how to use scalafix to produce cross builds

4 files changed, 83 insertions, 0 deletions

diff --git a/examples/cross-rewrite-example/Readme.md b/examples/cross-rewrite-example/Readme.md
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+++ b/examples/cross-rewrite-example/Readme.md
@@ -0,0 +1,5 @@
+This is an example of how to use scalafix rewrite rules to produce multiple
+variants of the same code base for different scala versions, e.g. 2.11.8 and
+2.12.1 and against different comparable libraries, e.g. cats and scalaz.
+
+To package the jars for all combinations run `cbt cross.package`.
diff --git a/examples/cross-rewrite-example/build/build.scala b/examples/cross-rewrite-example/build/build.scala
new file mode 100644
index 0000000..6d2ffac
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+++ b/examples/cross-rewrite-example/build/build.scala
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+package cbt_examples_build.cross_rewrite
+import cbt._
+import java.io.File
+import scala.meta._
+import scalafix.util._
+import scalafix.util.TreePatch._
+import scalafix.util.TokenPatch._
+
+class Build(val context: Context) extends BaseBuild{ outer =>
+  override def defaultScalaVersion = "2.11.8"
+
+  def versions = Seq[(String, Seq[Patch])](
+    scalaVersion -> Seq(),
+    "2.12.1" -> Seq(
+      RemoveGlobalImport(
+        importer"scala.concurrent.Future"
+      ),
+      AddGlobalImport(
+        importer"scala.util.Try"
+      )
+    )
+  )
+  def libs = Seq[(String, MavenDependency, Seq[Patch])](
+    (
+      "scalaz",
+      ScalaDependency( "org.scalaz", "scalaz-core", "7.2.2" ),
+      Seq(
+      )
+    ),
+    (
+      "cats",
+      ScalaDependency( "org.typelevel", "cats", "0.9.0" ),
+      Seq(
+      )
+    )
+  )
+
+  def cross = versions.flatMap{ case ( v, version_rewrites ) =>
+    libs.map{
+      case ( label, dep, lib_rewrites ) =>
+        val d = outer.target / "rewrites" / label ++ "-" ++ v
+        d.mkdirs
+        new Build(context) with Scalafix with PackageJars{
+          override def groupId = "org.cvogt"
+          override def artifactId = "cbt-examples-cross-rewrite-" + label
+          override def version = "0.1"
+          override def defaultScalaVersion = v
+          override def dependencies = super.dependencies ++ Resolver( mavenCentral ).bind( dep )
+          override def projectDirectory = d
+          override def scaladoc = None
+          override def sources = {
+            val fromTo = lib.autoRelative( outer.sources ).collect{
+              case (location, relative) if location.isFile
+                => location -> projectDirectory / "src" / relative
+            }
+
+            val to = fromTo.map(_._2)
+            assert( ( to diff to.distinct ).isEmpty )
+
+            Scalafix.apply(lib).config(
+              outer.classpath,
+              files = fromTo,
+              patches = lib_rewrites ++ version_rewrites,
+              allowEmpty = true
+            ).apply
+
+            to
+          }
+        }
+    }
+  }
+}
diff --git a/examples/cross-rewrite-example/build/build/build.scala b/examples/cross-rewrite-example/build/build/build.scala
new file mode 100644
index 0000000..404356f
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+++ b/examples/cross-rewrite-example/build/build/build.scala
@@ -0,0 +1,5 @@
+import cbt._
+
+class Build(val context: Context) extends BuildBuild {
+  override def dependencies = super.dependencies :+ plugins.scalafix
+}
diff --git a/examples/cross-rewrite-example/src/Main.scala b/examples/cross-rewrite-example/src/Main.scala
new file mode 100644
index 0000000..27ea3ff
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+++ b/examples/cross-rewrite-example/src/Main.scala
@@ -0,0 +1 @@
+import scala.concurrent.Future