From d9a93b04fc4910f38aa1ee39ac64aa93bbba9f15 Mon Sep 17 00:00:00 2001
From: Marek Moryl <moryl.moryl@gmail.com>
Date: Wed, 31 Aug 2022 22:41:59 +0200
Subject: [PATCH] Add platform option

---
 .../scala/cli/commands/SharedOptions.scala    |  4 +++
 .../cli/commands/util/SharedOptionsUtil.scala | 14 ++++++++---
 .../cli/integration/RunTestDefinitions.scala  | 18 +++++++++++++
 website/docs/commands/run.md                  | 25 +++++++++++++++++++
 website/docs/reference/cli-options.md         |  4 +++
 .../reference/scala-command/cli-options.md    |  4 +++
 6 files changed, 65 insertions(+), 4 deletions(-)

diff --git a/modules/cli-options/src/main/scala/scala/cli/commands/SharedOptions.scala b/modules/cli-options/src/main/scala/scala/cli/commands/SharedOptions.scala
index bba1ef8beb..68c4851db6 100644
--- a/modules/cli-options/src/main/scala/scala/cli/commands/SharedOptions.scala
+++ b/modules/cli-options/src/main/scala/scala/cli/commands/SharedOptions.scala
@@ -84,6 +84,10 @@ final case class SharedOptions(
   @Name("resourceDir")
     resourceDirs: List[String] = Nil,
 
+  @HelpMessage("Specify platform")
+  @ValueDescription("scala-js|scala-native|jvm")
+    platform: Option[String] = None,
+
   @Group("Scala")
   @Hidden
     scalaLibrary: Option[Boolean] = None,
diff --git a/modules/cli/src/main/scala/scala/cli/commands/util/SharedOptionsUtil.scala b/modules/cli/src/main/scala/scala/cli/commands/util/SharedOptionsUtil.scala
index 38321dd188..4f99827ba0 100644
--- a/modules/cli/src/main/scala/scala/cli/commands/util/SharedOptionsUtil.scala
+++ b/modules/cli/src/main/scala/scala/cli/commands/util/SharedOptionsUtil.scala
@@ -156,10 +156,16 @@ object SharedOptionsUtil extends CommandHelpers {
       jmhVersion: Option[String] = None,
       ignoreErrors: Boolean = false
     ): bo.BuildOptions = {
-      val platformOpt =
-        if (js.js) Some(Platform.JS)
-        else if (native.native) Some(Platform.Native)
-        else None
+      val platformStr = platform.map(Platform.normalize)
+      val platformOpt = platformStr.map(Platform.parse) match {
+        case Some(p) => p
+        case None =>
+          if (native.native && js.js) Some(Platform.Native)
+          else if (js.js) Some(Platform.JS)
+          else if (native.native) Some(Platform.Native)
+          else None
+      }
+
       bo.BuildOptions(
         scalaOptions = bo.ScalaOptions(
           scalaVersion = scalaVersion
diff --git a/modules/integration/src/test/scala/scala/cli/integration/RunTestDefinitions.scala b/modules/integration/src/test/scala/scala/cli/integration/RunTestDefinitions.scala
index 44073a3e62..4ae3d2387c 100644
--- a/modules/integration/src/test/scala/scala/cli/integration/RunTestDefinitions.scala
+++ b/modules/integration/src/test/scala/scala/cli/integration/RunTestDefinitions.scala
@@ -206,6 +206,24 @@ abstract class RunTestDefinitions(val scalaVersionOpt: Option[String])
     }
   }
 
+  test("simple script JS via platform option") {
+    val message = "Hello"
+    val inputs = TestInputs(
+      os.rel / "simple.sc" ->
+        s"""//> using platform "scala-native"
+           |import scala.scalajs.js
+           |val console = js.Dynamic.global.console
+           |val msg = "$message"
+           |console.log(msg)
+           |""".stripMargin
+    )
+    inputs.fromRoot { root =>
+      val output =
+        os.proc(TestUtil.cli, extraOptions, ".", "--platform", "js").call(cwd = root).out.trim()
+      expect(output == message)
+    }
+  }
+
   def platformNl: String = if (Properties.isWin) "\\r\\n" else "\\n"
 
   def simpleNativeTests(): Unit = {
diff --git a/website/docs/commands/run.md b/website/docs/commands/run.md
index 21b33fc6c3..b1f0f97eac 100644
--- a/website/docs/commands/run.md
+++ b/website/docs/commands/run.md
@@ -135,6 +135,12 @@ Note that this requires `node` to be [installed](/install#scala-js) on your syst
 scala-cli Hello.scala --js
 ```
 
+It is also possible to achieve it using `--platform` option:
+
+```bash
+scala-cli Hello.scala --platform js
+```
+
 See our dedicated [Scala.js guide](../guides/scala-js.md) for more information.
 
 ## Scala Native
@@ -146,8 +152,27 @@ Note that the [Scala Native requirements](https://scala-native.readthedocs.io/en
 scala-cli Hello.scala --native -S 2.13.6
 ```
 
+It is also possible to achieve it using `--platform` option:
+
+```bash
+scala-cli Hello.scala --platform native
+```
+
 We have a dedicated [Scala Native guide](../guides/scala-native.md) as well.
 
+## Platform
+
+The `--platform` option can be used to choose the platform, which should be used to compile and run application. Available platforms are:
+* JVM (`jvm`)
+* Scala.js (`scala.js` | `scala-js` | `scalajs` | `js`)
+* Scala Native (`scala-native` | `scalanative` | `native`)
+
+Please note that `--platform` option is prioritized over `--js` and `--native` options. For example, the following command will run using Scala Native:
+
+```bash
+scala-cli Hello.scala --js --platform scala-native
+```
+
 ## Scala Scripts
 
 Scala CLI can also compile and run Scala scripts:
diff --git a/website/docs/reference/cli-options.md b/website/docs/reference/cli-options.md
index a987493b16..f9d4688475 100644
--- a/website/docs/reference/cli-options.md
+++ b/website/docs/reference/cli-options.md
@@ -1260,6 +1260,10 @@ Aliases: `--resource-dir`
 
 Add a resource directory
 
+### `--platform`
+
+Specify platform
+
 ### `--scala-library`
 
 [Internal]
diff --git a/website/docs/reference/scala-command/cli-options.md b/website/docs/reference/scala-command/cli-options.md
index 4799915c3b..f506bf2aa3 100644
--- a/website/docs/reference/scala-command/cli-options.md
+++ b/website/docs/reference/scala-command/cli-options.md
@@ -670,6 +670,10 @@ Aliases: `--resource-dir`
 
 Add a resource directory
 
+### `--platform`
+
+Specify platform
+
 ### `--scala-library`
 
 [Internal]