Move all the source generation logic into a `shared.sc` file to avoid duplication

DRY it up internally

Move the Bridge downloading logic into `shared.sc` as well, and swap the subprocesses for in-memory processing using scalaj-http and ZipInputStream

1 files changed, 18 insertions, 129 deletions

diff --git a/build.sbt b/build.sbt
index 0907cddd..a15acc5a 100644
--- a/build.sbt
+++ b/build.sbt
@@ -12,124 +12,28 @@ val sharedSettings = Seq(
   resolvers += Resolver.sonatypeRepo("releases"),
   scalacOptions += "-P:acyclic:force",
   autoCompilerPlugins := true,
-  addCompilerPlugin("com.lihaoyi" %% "acyclic" % "0.1.7"),
-  libraryDependencies += "com.lihaoyi" % "ammonite" % "1.0.3-20-75e58ac" % "test" cross CrossVersion.full,
-
-  sourceGenerators in Test += Def.task {
-    val file = (sourceManaged in Test).value / "amm.scala"
-    IO.write(file, """object amm extends App { ammonite.Main().run() }""")
-    Seq(file)
-  }.taskValue
+  addCompilerPlugin("com.lihaoyi" %% "acyclic" % "0.1.7")
 )
 
 val coreSettings = Seq(
   sourceGenerators in Compile += Def.task {
-    object CodeGenerator {
-      private def generateLetters(n: Int) = {
-        val base = 'A'.toInt
-        (0 until n).map(i => (i + base).toChar)
-      }
-
-      def generateApplyer(dir: File) = {
-        def generate(n: Int) = {
-          val uppercases = generateLetters(n)
-          val lowercases = uppercases.map(Character.toLowerCase)
-          val typeArgs   = uppercases.mkString(", ")
-          val zipArgs    = lowercases.mkString(", ")
-          val parameters = lowercases.zip(uppercases).map { case (lower, upper) => s"$lower: TT[$upper]" }.mkString(", ")
-
-          val body   = s"mapCtx(zip($zipArgs)) { case (($zipArgs), z) => cb($zipArgs, z) }"
-          val zipmap = s"def zipMap[$typeArgs, Res]($parameters)(cb: ($typeArgs, Ctx) => Z[Res]) = $body"
-          val zip    = s"def zip[$typeArgs]($parameters): TT[($typeArgs)]"
-
-          if (n < 22) List(zipmap, zip).mkString(System.lineSeparator) else zip
-        }
-        val output = List(
-            "package mill.define",
-            "import scala.language.higherKinds",
-            "trait ApplyerGenerated[TT[_], Z[_], Ctx] {",
-            "def mapCtx[A, B](a: TT[A])(f: (A, Ctx) => Z[B]): TT[B]",
-            (2 to 22).map(generate).mkString(System.lineSeparator),
-            "}").mkString(System.lineSeparator)
-
-        val file = dir / "ApplicativeGenerated.scala"
-        IO.write(file, output)
-        file
-      }
-
-      def generateTarget(dir: File) = {
-        def generate(n: Int) = {
-          val uppercases = generateLetters(n)
-          val lowercases = uppercases.map(Character.toLowerCase)
-          val typeArgs   = uppercases.mkString(", ")
-          val args       = lowercases.mkString(", ")
-          val parameters = lowercases.zip(uppercases).map { case (lower, upper) => s"$lower: TT[$upper]" }.mkString(", ")
-          val body       = uppercases.zipWithIndex.map { case (t, i) => s"args[$t]($i)" }.mkString(", ")
-
-          s"def zip[$typeArgs]($parameters) = makeT[($typeArgs)](Seq($args), (args: Ctx) => ($body))"
-        }
-
-        val output = List(
-          "package mill.define",
-          "import scala.language.higherKinds",
-          "import mill.eval.Result",
-          "import mill.util.Ctx",
-          "trait TargetGenerated {",
-          "type TT[+X]",
-          "def makeT[X](inputs: Seq[TT[_]], evaluate: Ctx => Result[X]): TT[X]",
-          (3 to 22).map(generate).mkString(System.lineSeparator),
-          "}").mkString(System.lineSeparator)
-
-        val file = dir / "TaskGenerated.scala"
-        IO.write(file, output)
-        file
-      }
-
-      def generateSources(dir: File) = {
-        Seq(generateApplyer(dir), generateTarget(dir))
-      }
-    }
+    import sys.process._
     val dir = (sourceManaged in Compile).value
-    CodeGenerator.generateSources(dir)
+    if (!dir.exists()) {
+      IO.createDirectory(dir)
+      Seq("amm", "shared.sc", "generateSources", dir.toString).!
+    }
+    IO.listFiles(dir).toSeq
   }.taskValue,
 
   sourceGenerators in Test += Def.task {
-    object CodeGenerator {
-      private def generateLetters(n: Int) = {
-        val base = 'A'.toInt
-        (0 until n).map(i => (i + base).toChar)
-      }
-
-      def generateApplicativeTest(dir: File) = {
-        def generate(n: Int): String = {
-            val uppercases = generateLetters(n)
-            val lowercases = uppercases.map(Character.toLowerCase)
-            val typeArgs   = uppercases.mkString(", ")
-            val parameters = lowercases.zip(uppercases).map { case (lower, upper) => s"$lower: Option[$upper]" }.mkString(", ")
-            val result = lowercases.mkString(", ")
-            val forArgs = lowercases.map(i => s"$i <- $i").mkString("; ")
-            s"def zip[$typeArgs]($parameters) = { for ($forArgs) yield ($result) }"
-        }
-
-        val output = List(
-            "package mill.define",
-            "trait OptGenerated {",
-            (2 to 22).map(generate).mkString(System.lineSeparator),
-            "}"
-        ).mkString(System.lineSeparator)
-
-        val file = dir / "ApplicativeTestsGenerated.scala"
-        IO.write(file, output)
-        file
-      }
-
-      def generateTests(dir: File) = {
-        Seq(generateApplicativeTest(dir))
-      }
-    }
-
+    import sys.process._
     val dir = (sourceManaged in Test).value
-    CodeGenerator.generateTests(dir)
+    if (!dir.exists()) {
+      IO.createDirectory(dir)
+      Seq("amm", "shared.sc", "generateTests", dir.toString).!
+    }
+    IO.listFiles(dir).toSeq
   }.taskValue
 )
 
@@ -158,27 +62,12 @@ def bridge(bridgeVersion: String) = Project(
     ),
     (sourceGenerators in Compile) += Def.task{
       import sys.process._
-      import collection.JavaConverters._
-      val v = scalaBinaryVersion.value
-      val url =
-        s"http://repo1.maven.org/maven2/org/scala-sbt/compiler-bridge_$v/1.0.5/compiler-bridge_$v-1.0.5-sources.jar"
-      val curlDest = java.nio.file.Paths.get(target.value.toString, "sources")
-
-      if (!java.nio.file.Files.exists(curlDest)) {
-        Seq("rm", "-rf", curlDest.toString).!
-        java.nio.file.Files.createDirectories(curlDest)
-
-        Seq("curl", "-L", "-o", curlDest.resolve("bridge.jar").toString, url).!
-        Seq("unzip", curlDest.resolve("bridge.jar").toString, "-d", curlDest.toString).!
+      val dir = (sourceManaged in Compile).value
+      if (!dir.exists()) {
+        IO.createDirectory(dir)
+        Seq("amm", "shared.sc", "downloadBridgeSource", dir.toString, bridgeVersion).!
       }
-      val sources = java.nio.file.Files.walk(curlDest)
-        .iterator
-        .asScala
-        .filter(_.toString.endsWith(".scala"))
-        .map(_.toFile)
-        .toSeq
-
-      sources
+      (dir ** "*.scala").get
     }.taskValue
   )
 )