Add custom exception and throw it when node not found in the path (#2323)

* Add custom exception and throw it when node not found in the path

* Fix running integration test

---------

Co-authored-by: piotr-sekula <[email protected]>

Author: lwronski

modules/build/src/main/scala/scala/build/internal/Runner.scala

@@ -11,13 +11,7 @@ import java.nio.file.{Files, Path, Paths}
 
 import scala.build.EitherCps.{either, value}
 import scala.build.Logger
-import scala.build.errors.{
-  NoFrameworkFoundByBridgeError,
-  NoTestFrameworkFoundError,
-  NoTestsRun,
-  TestError,
-  TooManyFrameworksFoundByBridgeError
-}
+import scala.build.errors._
 import scala.build.testrunner.{AsmTestRunner, TestRunner}
 import scala.util.{Failure, Properties, Success}
 
@@ -232,11 +226,11 @@ object Runner {
     jsDom: Boolean = false,
     sourceMap: Boolean = false,
     esModule: Boolean = false
-  ): Process = {
+  ): Either[BuildException, Process] = either {
 
     import logger.{log, debug}
 
-    val nodePath = findInPath("node").fold("node")(_.toString)
+    val nodePath = value(findInPath("node").map(_.toString).toRight(NodeNotFoundError()))
 
     if (!jsDom && allowExecve && Execve.available()) {
 

modules/cli/src/main/scala/scala/cli/commands/run/Run.scala

@@ -456,15 +456,17 @@ object Run extends ScalaCommand[RunOptions] with BuildCommandHelpers {
             if (showCommand)
               Left(Runner.jsCommand(outputPath.toIO, args, jsDom = jsDom))
             else {
-              val process = Runner.runJs(
-                outputPath.toIO,
-                args,
-                logger,
-                allowExecve = allowExecve,
-                jsDom = jsDom,
-                sourceMap = build.options.scalaJsOptions.emitSourceMaps,
-                esModule = esModule
-              )
+              val process = value {
+                Runner.runJs(
+                  outputPath.toIO,
+                  args,
+                  logger,
+                  allowExecve = allowExecve,
+                  jsDom = jsDom,
+                  sourceMap = build.options.scalaJsOptions.emitSourceMaps,
+                  esModule = esModule
+                )
+              }
               process.onExit().thenApply(_ => if (os.exists(jsDest)) os.remove(jsDest))
               Right((process, None))
             }

modules/core/src/main/scala/scala/build/errors/NodeNotFoundError.scala

@@ -0,0 +1,5 @@
+package scala.build.errors
+
+final class NodeNotFoundError extends BuildException(
+      "The Node was not found on the PATH. Please ensure that Node is installed correctly and then try again"
+    )

modules/integration/src/test/scala/scala/cli/integration/RunScalaJsTestDefinitions.scala

@@ -31,6 +31,27 @@ trait RunScalaJsTestDefinitions { _: RunTestDefinitions =>
     simpleJsTest("--js-mode", "release")
   }
 
+  test("without node on the PATH") {
+    val fileName = "simple.sc"
+    val message  = "Hello"
+    val inputs = TestInputs(
+      os.rel / fileName ->
+        s"""import scala.scalajs.js
+           |val console = js.Dynamic.global.console
+           |val msg = "$message"
+           |console.log(msg)
+           |""".stripMargin
+    )
+    inputs.fromRoot { root =>
+      val thrown = os.proc(TestUtil.cli, extraOptions, fileName, "--js", "--server=false")
+        .call(cwd = root, env = Map("PATH" -> "", "PATHEXT" -> ""), check = false, mergeErrIntoOut = true)
+      val output = thrown.out.trim()
+
+      assert(thrown.exitCode == 1)
+      assert(output.contains("Node was not found on the PATH"))
+    }
+  }
+
   test("JS arguments") {
     val inputs = TestInputs(
       os.rel / "simple.sc" ->