flexiblize T.sources and use it widely, which lets us fix --watch

9 files changed, 96 insertions, 64 deletions

diff --git a/core/src/mill/define/Task.scala b/core/src/mill/define/Task.scala
index a94d9703..230089bf 100644
--- a/core/src/mill/define/Task.scala
+++ b/core/src/mill/define/Task.scala
@@ -126,32 +126,47 @@ object Target extends TargetGenerated with Applicative.Applyer[Task, Task, Resul
     )
   }
 
-  def source(value: Result[ammonite.ops.Path])
-            (implicit r: R[PathRef],
-             w: W[PathRef],
-             ctx: mill.define.Ctx): Input[PathRef] = macro sourceImpl
-
-  def sourceImpl(c: Context)
-                (value: c.Expr[Result[ammonite.ops.Path]])
-                (r: c.Expr[R[PathRef]],
-                 w: c.Expr[W[PathRef]],
-                 ctx: c.Expr[mill.define.Ctx]): c.Expr[Input[PathRef]] = {
+  def sources(values: Result[ammonite.ops.Path]*)
+             (implicit ctx: mill.define.Ctx): Sources = macro sourcesImpl1
+
+  def sourcesImpl1(c: Context)
+                  (values: c.Expr[Result[ammonite.ops.Path]]*)
+                  (ctx: c.Expr[mill.define.Ctx]): c.Expr[Sources] = {
     import c.universe._
-    val wrapped: c.Expr[Result[PathRef]] = reify(value.splice match{
-      case Result.Success(p) => Result.Success(PathRef(p))
-      case x: Result.Failing => x
-    })
-    mill.moduledefs.Cacher.impl0[Input[PathRef]](c)(
+    val wrapped =
+      for (value <- values.toList)
+      yield Applicative.impl0[Task, PathRef, mill.util.Ctx](c)(
+        reify(value.splice.map(PathRef(_))).tree
+      ).tree
+
+    mill.moduledefs.Cacher.impl0[Sources](c)(
       reify(
-        new Input[PathRef](
-          Applicative.impl0[Task, PathRef, mill.util.Ctx](c)(wrapped.tree).splice,
-          ctx.splice,
-          RW(w.splice.write, r.splice.read),
+        new Sources(
+          Task.sequence(c.Expr[List[Task[PathRef]]](q"scala.List(..$wrapped)").splice),
+          ctx.splice
         )
       )
     )
   }
 
+  def sources(values: Result[Seq[PathRef]])
+             (implicit ctx: mill.define.Ctx): Sources = macro sourcesImpl2
+
+  def sourcesImpl2(c: Context)
+                  (values: c.Expr[Result[Seq[PathRef]]])
+                  (ctx: c.Expr[mill.define.Ctx]): c.Expr[Sources] = {
+    import c.universe._
+
+
+    mill.moduledefs.Cacher.impl0[Sources](c)(
+      reify(
+        new Sources(
+          Applicative.impl0[Task, Seq[PathRef], mill.util.Ctx](c)(values.tree).splice,
+          ctx.splice
+        )
+      )
+    )
+  }
   def input[T](value: Result[T])
               (implicit r: R[T],
                 w: W[T],
@@ -305,7 +320,15 @@ class Input[T](t: Task[T],
                val readWrite: RW[_]) extends NamedTaskImpl[T](ctx0, t) with Target[T]{
   override def sideHash = util.Random.nextInt()
 }
-
+class Sources(t: Task[Seq[PathRef]],
+              ctx0: mill.define.Ctx) extends Input[Seq[PathRef]](
+  t,
+  ctx0,
+  RW(
+    upickle.default.SeqishW[PathRef, Seq].write,
+    upickle.default.SeqishR[Seq, PathRef].read
+  )
+)
 object Task {
 
   class Task0[T](t: T) extends Task[T]{
diff --git a/core/src/mill/main/MainRunner.scala b/core/src/mill/main/MainRunner.scala
index 06e1795f..e3820e3d 100644
--- a/core/src/mill/main/MainRunner.scala
+++ b/core/src/mill/main/MainRunner.scala
@@ -24,6 +24,7 @@ class MainRunner(config: ammonite.main.Cli.Config,
     config, outprintStream, errPrintStream,
     stdIn, outprintStream, errPrintStream
   ){
+
   var lastEvaluator: Option[(Seq[(Path, Long)], Evaluator[Any])] = None
 
   override def runScript(scriptPath: Path, scriptArgs: List[String]) =
diff --git a/core/src/mill/main/RunScript.scala b/core/src/mill/main/RunScript.scala
index e5c92e3e..a05c7623 100644
--- a/core/src/mill/main/RunScript.scala
+++ b/core/src/mill/main/RunScript.scala
@@ -161,8 +161,9 @@ object RunScript{
     val watched = evaluated.results
       .iterator
       .collect {
-        case (t: define.Input[_], Result.Success(p: PathRef)) => p
+        case (t: define.Sources, Result.Success(p: Seq[PathRef])) => p
       }
+      .flatten
       .toSeq
 
     val errorStr =
diff --git a/core/test/resources/examples/javac/build.sc b/core/test/resources/examples/javac/build.sc
index 8f250014..0783ac17 100644
--- a/core/test/resources/examples/javac/build.sc
+++ b/core/test/resources/examples/javac/build.sc
@@ -12,11 +12,11 @@ def resourceRootPath = millSourcePath / 'resources
 //                                |
 //                                v
 //           resourceRoot ---->  jar
-def sourceRoot = T.source{ sourceRootPath }
-def resourceRoot = T.source{ resourceRootPath }
-def allSources = T{ ls.rec(sourceRoot().path).map(PathRef(_)) }
+def sourceRoot = T.sources{ sourceRootPath }
+def resourceRoot = T.sources{ resourceRootPath }
+def allSources = T{ sourceRoot().flatMap(p => ls.rec(p.path)).map(PathRef(_)) }
 def classFiles = T{ compileAll(allSources()) }
-def jar = T{ Jvm.createJar(Loose.Agg(resourceRoot().path, classFiles().path)) }
+def jar = T{ Jvm.createJar(Loose.Agg(classFiles().path) ++ resourceRoot().map(_.path)) }
 
 def run(mainClsName: String) = T.command{
   %%('java, "-cp", classFiles().path, mainClsName)(T.ctx().dest)
diff --git a/core/test/src/mill/eval/JavaCompileJarTests.scala b/core/test/src/mill/eval/JavaCompileJarTests.scala
index a67d669d..71feebda 100644
--- a/core/test/src/mill/eval/JavaCompileJarTests.scala
+++ b/core/test/src/mill/eval/JavaCompileJarTests.scala
@@ -35,11 +35,11 @@ object JavaCompileJarTests extends TestSuite{
         //                                |
         //                                v
         //           resourceRoot ---->  jar
-        def sourceRoot = T.source{ sourceRootPath }
-        def resourceRoot = T.source{ resourceRootPath }
-        def allSources = T{ ls.rec(sourceRoot().path).map(PathRef(_)) }
+        def sourceRoot = T.sources{ sourceRootPath }
+        def resourceRoot = T.sources{ resourceRootPath }
+        def allSources = T{ sourceRoot().flatMap(p => ls.rec(p.path)).map(PathRef(_)) }
         def classFiles = T{ compileAll(allSources()) }
-        def jar = T{ Jvm.createJar(Loose.Agg(resourceRoot().path, classFiles().path)) }
+        def jar = T{ Jvm.createJar(Loose.Agg(classFiles().path) ++ resourceRoot().map(_.path)) }
 
         def run(mainClsName: String) = T.command{
           %%('java, "-cp", classFiles().path, mainClsName)
@@ -108,12 +108,12 @@ object JavaCompileJarTests extends TestSuite{
       val jarContents = %%('jar, "-tf", evaluator.outPath/'jar/'dest/"out.jar")(evaluator.outPath).out.string
       val expectedJarContents =
         """META-INF/MANIFEST.MF
-          |hello.txt
           |test/Bar.class
           |test/BarThree.class
           |test/BarTwo.class
           |test/Foo.class
           |test/FooTwo.class
+          |hello.txt
           |""".stripMargin
       assert(jarContents == expectedJarContents)
 
diff --git a/docs/tasks.md b/docs/tasks.md
index ef9270bb..73695bb8 100644
--- a/docs/tasks.md
+++ b/docs/tasks.md
@@ -7,14 +7,16 @@ The following is a simple self-contained example using Mill to compile Java:
 ```scala
 import ammonite.ops._, mill._
 
-def sourceRootPath = pwd / 'src
-def resourceRootPath = pwd / 'resources
+// sourceRoot -> allSources -> classFiles
+//                                |
+//                                v
+//           resourceRoot ---->  jar
 
-def sourceRoot = T.source{ sourceRootPath }
+def sourceRoot = T.sources{ pwd / 'src }
 
-def resourceRoot = T.source{ resourceRootPath }
+def resourceRoot = T.sources{ pwd / 'resources }
 
-def allSources = T{ ls.rec(sourceRoot().path).map(PathRef(_)) }
+def allSources = T{ sourceRoot().flatMap(p => ls.rec(p.path)).map(PathRef(_)) }
 
 def classFiles = T{ 
   mkdir(T.ctx().dest)
@@ -23,7 +25,7 @@ def classFiles = T{
   PathRef(T.ctx().dest) 
 }
 
-def jar = T{ mill.modules.Jvm.createJar(Agg(resourceRoot().path, classFiles().path)) }
+def jar = T{ Jvm.createJar(Loose.Agg(classFiles().path) ++ resourceRoot().map(_.path)) }
 
 def run(mainClsName: String) = T.command{
   %%('java, "-cp", classFiles().path, mainClsName)
@@ -116,13 +118,23 @@ within a `Module` body
 ```scala
 def sourceRootPath = pwd / 'src
 
-def sourceRoot = T.source{ sourceRootPath }
+def sourceRoots = T.sources{ sourceRootPath }
 ```
 
-`Source`s are defined using `T.source{ ... }`, taking an `ammonite.ops.Path` as
-an input. A `Source` is a subclass of `Target[PathRef]`: this means that it's
-build signature/`hashCode` depends not just on the path it refers to (e.g.
-`foo/bar/baz`) but also the MD5 hash of the filesystem tree under that path.
+`Source`s are defined using `T.source{ ... }`, taking one-or-more
+`ammonite.ops.Path`s as arguments. A `Source` is a subclass of
+`Target[Seq[PathRef]]`: this means that it's build signature/`hashCode` depends
+not just on the path it refers to (e.g. `foo/bar/baz`) but also the MD5 hash of
+the filesystem tree under that path.
+
+`T.source` also has an overload which takes `Seq[PathRef]`, to let you
+override-and-extend source lists the same way you would any other `T{...}`
+definition:
+
+```scala
+def additionalSources = T.sources{ pwd / 'additionalSources }
+def sourceRoots = T.sources{ super.sourceRoots() ++ additionalSources() }
+```
 
 ### Commands
 
diff --git a/scalajslib/test/src/mill/scalajslib/HelloJSWorldTests.scala b/scalajslib/test/src/mill/scalajslib/HelloJSWorldTests.scala
index 12102666..4043feff 100644
--- a/scalajslib/test/src/mill/scalajslib/HelloJSWorldTests.scala
+++ b/scalajslib/test/src/mill/scalajslib/HelloJSWorldTests.scala
@@ -36,7 +36,7 @@ object HelloJSWorldTests extends TestSuite {
     class BuildModuleUtest(scalaVersion0: String, sjsVersion0: String)
       extends BuildModule(scalaVersion0: String, sjsVersion0: String) {
       object test extends super.Tests {
-        override def sources = T.input{ Agg(PathRef(millSourcePath / 'src / 'utest)) }
+        override def sources = T.sources{ millSourcePath / 'src / 'utest }
         def testFramework: T[String] = "utest.runner.Framework"
         override def ivyDeps = Agg(
           ivy"com.lihaoyi:utest_sjs${scalaJSBinaryVersion()}_${Lib.scalaBinaryVersion(scalaVersion())}:0.6.3"
@@ -48,7 +48,7 @@ object HelloJSWorldTests extends TestSuite {
     class BuildModuleScalaTest(scalaVersion0: String, sjsVersion0: String)
       extends BuildModule(scalaVersion0: String, sjsVersion0: String) {
       object test extends super.Tests {
-        override def sources = T.input{ Agg(PathRef(millSourcePath / 'src / 'scalatest)) }
+        override def sources = T.sources{ millSourcePath / 'src / 'scalatest }
         def testFramework: T[String] = "org.scalatest.tools.Framework"
         override def ivyDeps = Agg(
           ivy"org.scalatest:scalatest_sjs${scalaJSBinaryVersion()}_${Lib.scalaBinaryVersion(scalaVersion())}:3.0.4"
diff --git a/scalalib/src/mill/scalalib/MiscModule.scala b/scalalib/src/mill/scalalib/MiscModule.scala
index e4d8a8b0..8576e788 100644
--- a/scalalib/src/mill/scalalib/MiscModule.scala
+++ b/scalalib/src/mill/scalalib/MiscModule.scala
@@ -37,14 +37,13 @@ trait CrossModuleBase extends mill.Module{
 }
 
 trait CrossScalaModule extends ScalaModule with CrossModuleBase{ outer =>
-  override def sources = T.input{
+  override def sources = T.sources{
     super.sources() ++
     CrossModuleBase.scalaVersionPaths(crossScalaVersion, s => millSourcePath / s"src-$s" )
-
   }
 
   trait Tests extends super.Tests {
-    override def sources = T.input{
+    override def sources = T.sources{
       super.sources() ++
       CrossModuleBase.scalaVersionPaths(crossScalaVersion, s => millSourcePath / s"src-$s" )
     }
@@ -52,28 +51,24 @@ trait CrossScalaModule extends ScalaModule with CrossModuleBase{ outer =>
 }
 
 trait SbtModule extends ScalaModule { outer =>
-  override def sources = T.input{
-    Agg(
-      PathRef(millSourcePath / 'src / 'main / 'scala),
-      PathRef(millSourcePath / 'src / 'main / 'java)
-    )
-  }
-  override def resources = T.input{ Agg(PathRef(millSourcePath / 'src / 'main / 'resources)) }
+  override def sources = T.sources(
+    millSourcePath / 'src / 'main / 'scala,
+    millSourcePath / 'src / 'main / 'java
+  )
+  override def resources = T.sources{ millSourcePath / 'src / 'main / 'resources }
   trait Tests extends super.Tests {
     override def millSourcePath = outer.millSourcePath
-    override def sources = T.input{
-      Agg(
-        PathRef(millSourcePath / 'src / 'test / 'scala),
-        PathRef(millSourcePath / 'src / 'test / 'java)
-      )
-    }
-    override def resources = T.input{ Agg(PathRef(millSourcePath / 'src / 'test / 'resources)) }
+    override def sources = T.sources(
+      millSourcePath / 'src / 'test / 'scala,
+      millSourcePath / 'src / 'test / 'java
+    )
+    override def resources = T.sources{ millSourcePath / 'src / 'test / 'resources }
   }
 }
 
 trait CrossSbtModule extends SbtModule with CrossModuleBase{ outer =>
 
-  override def sources = T.input{
+  override def sources = T.sources{
     super.sources() ++
     CrossModuleBase.scalaVersionPaths(
       crossScalaVersion,
@@ -83,7 +78,7 @@ trait CrossSbtModule extends SbtModule with CrossModuleBase{ outer =>
   }
   trait Tests extends super.Tests {
     override def millSourcePath = outer.millSourcePath
-    override def sources = T.input{
+    override def sources = T.sources{
       super.sources() ++
       CrossModuleBase.scalaVersionPaths(
         crossScalaVersion,
diff --git a/scalalib/src/mill/scalalib/ScalaModule.scala b/scalalib/src/mill/scalalib/ScalaModule.scala
index 92068487..03e27596 100644
--- a/scalalib/src/mill/scalalib/ScalaModule.scala
+++ b/scalalib/src/mill/scalalib/ScalaModule.scala
@@ -126,8 +126,8 @@ trait ScalaModule extends mill.Module with TaskModule { outer =>
 
   def prependShellScript: T[String] = T{ "" }
 
-  def sources = T.input{ Agg(PathRef(millSourcePath / 'src)) }
-  def resources = T.input{ Agg(PathRef(millSourcePath / 'resources)) }
+  def sources = T.sources{ millSourcePath / 'src }
+  def resources = T.sources{ millSourcePath / 'resources }
   def generatedSources = T { Agg.empty[PathRef] }
   def allSources = T{ sources() ++ generatedSources() }