Add support for scalaJSOutputPatterns

scalajslib/src/mill/scalajslib/ScalaJSModule.scala

@@ -8,14 +8,7 @@ import mill.scalalib.Lib.resolveDependencies
 import mill.scalalib.{Dep, DepSyntax, Lib, TestModule}
 import mill.testrunner.TestRunner
 import mill.define.{Command, Target, Task}
-import mill.scalajslib.api.{
-  ESFeatures,
-  ESVersion,
-  JsEnvConfig,
-  ModuleKind,
-  ModuleSplitStyle,
-  Report
-}
+import mill.scalajslib.api._
 import mill.scalajslib.internal.ScalaJSUtils.getReportMainFilePathRef
 import mill.scalajslib.worker.{ScalaJSWorker, ScalaJSWorkerExternalModule}
 
@@ -121,7 +114,8 @@ trait ScalaJSModule extends scalalib.ScalaModule { outer =>
       sourceMap = scalaJSSourceMap(),
       moduleKind = moduleKind(),
       esFeatures = esFeatures(),
-      moduleSplitStyle = moduleSplitStyle()
+      moduleSplitStyle = moduleSplitStyle(),
+      outputPatterns = scalaJSOutputPatterns()
     )
   }
 
@@ -161,7 +155,8 @@ trait ScalaJSModule extends scalalib.ScalaModule { outer =>
       sourceMap: Boolean,
       moduleKind: ModuleKind,
       esFeatures: ESFeatures,
-      moduleSplitStyle: ModuleSplitStyle
+      moduleSplitStyle: ModuleSplitStyle,
+      outputPatterns: OutputPatterns
   )(implicit ctx: mill.api.Ctx): Result[Report] = {
     val outputPath = ctx.dest
 
@@ -186,7 +181,8 @@ trait ScalaJSModule extends scalalib.ScalaModule { outer =>
       sourceMap = sourceMap,
       moduleKind = moduleKind,
       esFeatures = esFeatures,
-      moduleSplitStyle = moduleSplitStyle
+      moduleSplitStyle = moduleSplitStyle,
+      outputPatterns = outputPatterns
     )
   }
 
@@ -238,6 +234,9 @@ trait ScalaJSModule extends scalalib.ScalaModule { outer =>
   /** Whether to emit a source map. */
   def scalaJSSourceMap: Target[Boolean] = T { true }
 
+  /** Name patterns for output. */
+  def scalaJSOutputPatterns: Target[OutputPatterns] = T { OutputPatterns.Defaults }
+
   @internal
   override def bspBuildTargetData: Task[Option[(String, AnyRef)]] = T.task {
     Some((
@@ -281,7 +280,8 @@ trait TestScalaJSModule extends ScalaJSModule with TestModule {
       sourceMap = scalaJSSourceMap(),
       moduleKind = moduleKind(),
       esFeatures = esFeatures(),
-      moduleSplitStyle = moduleSplitStyle()
+      moduleSplitStyle = moduleSplitStyle(),
+      outputPatterns = scalaJSOutputPatterns()
     )
   }
 

scalajslib/src/mill/scalajslib/api/ScalaJSApi.scala

@@ -107,3 +107,93 @@ object JsEnvConfig {
       autoExit: Boolean
   ) extends JsEnvConfig
 }
+
+class OutputPatterns private (
+  val jsFile: String,
+  val sourceMapFile: String,
+  val moduleName: String,
+  val jsFileURI: String,
+  val sourceMapURI: String
+) {
+
+  /** Pattern for the JS file name (the file containing the module's code). */
+  def withJSFile(jsFile: String): OutputPatterns =
+    copy(jsFile = jsFile)
+
+  /** Pattern for the file name of the source map file of the JS file. */
+  def withSourceMapFile(sourceMapFile: String): OutputPatterns =
+    copy(sourceMapFile = sourceMapFile)
+
+  /** Pattern for the module name (the string used to import a module). */
+  def withModuleName(moduleName: String): OutputPatterns =
+    copy(moduleName = moduleName)
+
+  /** Pattern for the "file" field in the source map. */
+  def withJSFileURI(jsFileURI: String): OutputPatterns =
+    copy(jsFileURI = jsFileURI)
+
+  /** Pattern for the source map URI in the JS file. */
+  def withSourceMapURI(sourceMapURI: String): OutputPatterns =
+    copy(sourceMapURI = sourceMapURI)
+
+  override def toString(): String = {
+    s"""OutputPatterns(
+       |  jsFile        = $jsFile,
+       |  sourceMapFile = $sourceMapFile,
+       |  moduleName    = $moduleName,
+       |  jsFileURI     = $jsFileURI,
+       |  sourceMapURI  = $sourceMapURI,
+       |)""".stripMargin
+  }
+
+  private def copy(
+      jsFile: String = jsFile,
+      sourceMapFile: String = sourceMapFile,
+      moduleName: String = moduleName,
+      jsFileURI: String = jsFileURI,
+      sourceMapURI: String = sourceMapURI
+  ): OutputPatterns = {
+    new OutputPatterns(jsFile, sourceMapFile, moduleName, jsFileURI, sourceMapURI)
+  }
+}
+
+object OutputPatterns {
+
+  /** Default [[OutputPatterns]]; equivalent to `fromJSFile("%s.js")`. */
+  val Defaults: OutputPatterns = fromJSFile("%s.js")
+
+  /**
+   * Creates [[OutputPatterns]] from a JS file pattern.
+   *
+   *  Other patterns are derived from the JS file pattern as follows:
+   *  - `sourceMapFile`: ".map" is appended.
+   *  - `moduleName`: "./" is prepended (relative path import).
+   *  - `jsFileURI`: relative URI (same as the provided pattern).
+   *  - `sourceMapURI`: relative URI (same as `sourceMapFile`).
+   */
+  def fromJSFile(jsFile: String): OutputPatterns = {
+    new OutputPatterns(
+      jsFile = jsFile,
+      sourceMapFile = s"$jsFile.map",
+      moduleName = s"./$jsFile",
+      jsFileURI = jsFile,
+      sourceMapURI = s"$jsFile.map"
+    )
+  }
+
+  private def apply(
+      jsFile: String,
+      sourceMapFile: String,
+      moduleName: String,
+      jsFileURI: String,
+      sourceMapURI: String
+  ): OutputPatterns = new OutputPatterns(
+    jsFile,
+    sourceMapFile,
+    moduleName,
+    jsFileURI,
+    sourceMapURI
+  )
+
+  implicit val rw: RW[OutputPatterns] = macroRW[OutputPatterns]
+}

scalajslib/src/mill/scalajslib/worker/ScalaJSWorker.scala

@@ -127,6 +127,16 @@ private[scalajslib] class ScalaJSWorker extends AutoCloseable {
     )
   }
 
+  private def toWorkerApi(outputPatterns: api.OutputPatterns): workerApi.OutputPatterns = {
+    workerApi.OutputPatterns(
+      jsFile = outputPatterns.jsFile,
+      sourceMapFile = outputPatterns.sourceMapFile,
+      moduleName = outputPatterns.moduleName,
+      jsFileURI = outputPatterns.jsFileURI,
+      sourceMapURI = outputPatterns.sourceMapURI
+    )
+  }
+
   def link(
       toolsClasspath: Agg[mill.PathRef],
       sources: Agg[os.Path],
@@ -140,7 +150,8 @@ private[scalajslib] class ScalaJSWorker extends AutoCloseable {
       sourceMap: Boolean,
       moduleKind: api.ModuleKind,
       esFeatures: api.ESFeatures,
-      moduleSplitStyle: api.ModuleSplitStyle
+      moduleSplitStyle: api.ModuleSplitStyle,
+      outputPatterns: api.OutputPatterns
   )(implicit ctx: Ctx.Home): Result[api.Report] = {
     bridge(toolsClasspath).link(
       sources = sources.items.map(_.toIO).toArray,
@@ -154,7 +165,8 @@ private[scalajslib] class ScalaJSWorker extends AutoCloseable {
       sourceMap = sourceMap,
       moduleKind = toWorkerApi(moduleKind),
       esFeatures = toWorkerApi(esFeatures),
-      moduleSplitStyle = toWorkerApi(moduleSplitStyle)
+      moduleSplitStyle = toWorkerApi(moduleSplitStyle),
+      outputPatterns = toWorkerApi(outputPatterns)
     ) match {
       case Right(report) => Result.Success(fromWorkerApi(report))
       case Left(message) => Result.Failure(message)

scalajslib/test/src/OutputPatternsTests.scala

@@ -0,0 +1,51 @@
+package mill.scalajslib
+
+import mill._
+import mill.define.Discover
+import mill.scalajslib.api._
+import mill.util.{TestEvaluator, TestUtil}
+import utest._
+
+object OutputPatternsTests extends TestSuite {
+  val workspacePath = TestUtil.getOutPathStatic() / "hello-js-world"
+
+  object OutputPatternsModule extends TestUtil.BaseModule {
+
+    object outputPatternsModule extends ScalaJSModule {
+      override def millSourcePath = workspacePath
+      override def scalaVersion = sys.props.getOrElse("TEST_SCALA_2_13_VERSION", ???)
+      override def scalaJSVersion = "1.12.0"
+      override def moduleKind = ModuleKind.CommonJSModule
+      override def scalaJSOutputPatterns = OutputPatterns.fromJSFile("%s.mjs")
+    }
+
+    override lazy val millDiscover = Discover[this.type]
+  }
+
+  val millSourcePath = os.pwd / "scalajslib" / "test" / "resources" / "hello-js-world"
+
+  val evaluator = TestEvaluator.static(OutputPatternsModule)
+
+  val tests: Tests = Tests {
+    prepareWorkspace()
+
+    test("output patterns") {
+      val Right((report, _)) =
+        evaluator(OutputPatternsModule.outputPatternsModule.fastLinkJS)
+      val publicModules = report.publicModules.toSeq
+      assert(publicModules.length == 1)
+      val main = publicModules(0)
+      assert(main.jsFileName == "main.mjs")
+      assert(os.exists(report.dest.path / "main.mjs"))
+      assert(main.sourceMapName == Some("main.mjs.map"))
+      assert(os.exists(report.dest.path / "main.mjs.map"))
+    }
+  }
+
+  def prepareWorkspace(): Unit = {
+    os.remove.all(workspacePath)
+    os.makeDir.all(workspacePath / os.up)
+    os.copy(millSourcePath, workspacePath)
+  }
+
+}

scalajslib/worker-api/src/ScalaJSWorkerApi.scala

@@ -15,7 +15,8 @@ private[scalajslib] trait ScalaJSWorkerApi {
       sourceMap: Boolean,
       moduleKind: ModuleKind,
       esFeatures: ESFeatures,
-      moduleSplitStyle: ModuleSplitStyle
+      moduleSplitStyle: ModuleSplitStyle,
+      outputPatterns: OutputPatterns
   ): Either[String, Report]
 
   def run(config: JsEnvConfig, report: Report): Unit
@@ -102,3 +103,11 @@ private[scalajslib] object ModuleSplitStyle {
   case object SmallestModules extends ModuleSplitStyle
   final case class SmallModulesFor(packages: List[String]) extends ModuleSplitStyle
 }
+
+private[scalajslib] final case class OutputPatterns(
+  jsFile: String,
+  sourceMapFile: String,
+  moduleName: String,
+  jsFileURI: String,
+  sourceMapURI: String
+)

scalajslib/worker/0.6/src/ScalaJSWorkerImpl.scala

@@ -83,7 +83,8 @@ class ScalaJSWorkerImpl extends ScalaJSWorkerApi {
       sourceMap: Boolean, // ignored in 0.6
       moduleKind: ModuleKind,
       esFeatures: ESFeatures,
-      moduleSplitStyle: ModuleSplitStyle // ignored in 0.6
+      moduleSplitStyle: ModuleSplitStyle, // ignored in 0.6
+      outputPatterns: OutputPatterns // ignored in 0.6
   ): Either[String, Report] = {
     val linker = ScalaJSLinker.reuseOrCreate(LinkerInput(
       isFullLinkJS = isFullLinkJS,

scalajslib/worker/1/src/ScalaJSWorkerImpl.scala

@@ -16,6 +16,7 @@ import org.scalajs.linker.interface.{
   ESFeatures => ScalaJSESFeatures,
   ESVersion => ScalaJSESVersion,
   ModuleKind => ScalaJSModuleKind,
+  OutputPatterns => ScalaJSOutputPatterns,
   Report => ScalaJSReport,
   ModuleSplitStyle => _,
   _
@@ -37,6 +38,7 @@ class ScalaJSWorkerImpl extends ScalaJSWorkerApi {
       moduleKind: ModuleKind,
       esFeatures: ESFeatures,
       moduleSplitStyle: ModuleSplitStyle,
+      outputPatterns: OutputPatterns,
       dest: File
   )
   private def minorIsGreaterThanOrEqual(number: Int) = ScalaJSVersions.current match {
@@ -98,31 +100,14 @@ class ScalaJSWorkerImpl extends ScalaJSWorkerApi {
         else withESVersion_1_5_minus(scalaJSESFeatures)
 
       val useClosure = input.isFullLinkJS && input.moduleKind != ModuleKind.ESModule
-      val partialConfig = StandardConfig()
+      var partialConfig = StandardConfig()
         .withOptimizer(input.optimizer)
         .withClosureCompilerIfAvailable(useClosure)
         .withSemantics(semantics)
         .withModuleKind(scalaJSModuleKind)
         .withESFeatures(scalaJSESFeatures)
         .withSourceMap(input.sourceMap)
 
-      // Separating ModuleSplitStyle in a standalone object avoids
-      // early classloading which fails in Scala.js versions where
-      // the classes don't exist
-      object ScalaJSModuleSplitStyle {
-        import org.scalajs.linker.interface.ModuleSplitStyle
-        object SmallModulesFor {
-          def apply(packages: List[String]): ModuleSplitStyle =
-            ModuleSplitStyle.SmallModulesFor(packages)
-        }
-        object FewestModules {
-          def apply(): ModuleSplitStyle = ModuleSplitStyle.FewestModules
-        }
-        object SmallestModules {
-          def apply(): ModuleSplitStyle = ModuleSplitStyle.SmallestModules
-        }
-      }
-
       def withModuleSplitStyle_1_3_plus(config: StandardConfig): StandardConfig = {
         config.withModuleSplitStyle(
           input.moduleSplitStyle match {
@@ -147,11 +132,24 @@ class ScalaJSWorkerImpl extends ScalaJSWorkerApi {
         config
       }
 
-      val config =
+      val withModuleSplitStyle =
         if (minorIsGreaterThanOrEqual(3)) withModuleSplitStyle_1_3_plus(partialConfig)
         else withModuleSplitStyle_1_2_minus(partialConfig)
 
-      StandardImpl.clearableLinker(config)
+      val withOutputPatterns =
+        if (minorIsGreaterThanOrEqual(3))
+          withModuleSplitStyle
+            .withOutputPatterns(
+              ScalaJSOutputPatterns.Defaults
+                .withJSFile(input.outputPatterns.jsFile)
+                .withJSFileURI(input.outputPatterns.jsFileURI)
+                .withModuleName(input.outputPatterns.moduleName)
+                .withSourceMapFile(input.outputPatterns.sourceMapFile)
+                .withSourceMapURI(input.outputPatterns.sourceMapURI)
+            )
+        else withModuleSplitStyle
+
+      StandardImpl.clearableLinker(withOutputPatterns)
     }
   }
   def link(
@@ -166,7 +164,8 @@ class ScalaJSWorkerImpl extends ScalaJSWorkerApi {
       sourceMap: Boolean,
       moduleKind: ModuleKind,
       esFeatures: ESFeatures,
-      moduleSplitStyle: ModuleSplitStyle
+      moduleSplitStyle: ModuleSplitStyle,
+      outputPatterns: OutputPatterns
   ): Either[String, Report] = {
     // On Scala.js 1.2- we want to use the legacy mode either way since
     // the new mode is not supported and in tests we always use legacy = false
@@ -179,6 +178,7 @@ class ScalaJSWorkerImpl extends ScalaJSWorkerApi {
       moduleKind = moduleKind,
       esFeatures = esFeatures,
       moduleSplitStyle = moduleSplitStyle,
+      outputPatterns = outputPatterns,
       dest = dest
     ))
     val cache = StandardImpl.irFileCache().newCache
@@ -339,3 +339,20 @@ class ScalaJSWorkerImpl extends ScalaJSWorkerApi {
     Seq(input)
   }
 }
+
+// Separating ModuleSplitStyle in a standalone object avoids
+// early classloading which fails in Scala.js versions where
+// the classes don't exist
+object ScalaJSModuleSplitStyle {
+  import org.scalajs.linker.interface.ModuleSplitStyle
+  object SmallModulesFor {
+    def apply(packages: List[String]): ModuleSplitStyle =
+      ModuleSplitStyle.SmallModulesFor(packages)
+  }
+  object FewestModules {
+    def apply(): ModuleSplitStyle = ModuleSplitStyle.FewestModules
+  }
+  object SmallestModules {
+    def apply(): ModuleSplitStyle = ModuleSplitStyle.SmallestModules
+  }
+}