Expand Java properties in class paths passed via --extra-jars

modules/cli-tests/src/main/scala/coursier/clitests/LaunchTests.scala

@@ -6,7 +6,7 @@ import utest._
 
 import scala.util.Properties
 
-abstract class LaunchTests extends TestSuite {
+abstract class LaunchTests extends TestSuite with LauncherOptions {
 
   def launcher: String
 
@@ -175,5 +175,38 @@ abstract class LaunchTests extends TestSuite {
         assert(output.containsSlice(expectedFirstLines))
       }
     }
+
+    test("extra jars with properties") {
+      if (acceptsJOptions)
+        extraJarsWithProperties()
+      else
+        "Disabled"
+    }
+    def extraJarsWithProperties(): Unit = {
+      val files = os.proc(launcher, "fetch", "org.scala-lang:scala3-compiler_3:3.1.3")
+        .call()
+        .out.lines()
+        .map(os.Path(_, os.pwd))
+      TestUtil.withTempDir { tmpDir0 =>
+        val tmpDir = os.Path(tmpDir0, os.pwd)
+        val dir    = tmpDir / "cp"
+        for (f <- files)
+          os.copy.into(f, dir, createFolders = true)
+        val output = os.proc(
+          launcher,
+          s"-J-Dthe.directory=$dir",
+          "launch",
+          "--extra-jars",
+          s"$${the.directory}/*",
+          "-M",
+          "dotty.tools.MainGenericCompiler"
+        ).call(mergeErrIntoOut = true).out.lines()
+        val expectedFirstLines = Seq(
+          "Usage: scalac <options> <source files>",
+          "where possible standard options include:"
+        )
+        assert(output.containsSlice(expectedFirstLines))
+      }
+    }
   }
 }

modules/cli-tests/src/test/scala/coursier/clitests/PackLaunchTests.scala

@@ -1,5 +1,5 @@
 package coursier.clitests
 
-object PackLaunchTests extends LaunchTests {
+object PackLaunchTests extends LaunchTests with PackLauncherOptions {
   val launcher = LauncherTestUtil.launcher
 }

modules/cli/src/main/scala/coursier/cli/params/SharedLaunchParams.scala

@@ -79,7 +79,7 @@ object SharedLaunchParams {
     }
 
     // check if those exist?
-    val extraJars = options.extraJars.flatMap(ClassPathUtil.classPath)
+    val extraJars = options.extraJars.flatMap(ClassPathUtil.classPath(_, sys.props.get))
 
     (resolveV, artifactV, sharedLoaderV, propertiesV).mapN {
       (resolve, artifact, sharedLoader, properties) =>

modules/cli/src/main/scala/coursier/cli/util/ClassPathUtil.scala

@@ -2,13 +2,35 @@ package coursier.cli.util
 
 import java.io.File
 import java.nio.file.{Files, Path, Paths}
+import java.util.regex.{Matcher, Pattern}
 
 import scala.collection.JavaConverters._
 
 object ClassPathUtil {
 
-  def classPath(input: String): Seq[Path] =
+  private val propertyRegex = Pattern.compile(
+    Pattern.quote("${") + "[^" + Pattern.quote("{[()]}") + "]*" + Pattern.quote("}")
+  )
+
+  def classPath(input: String, getProperty: String => Option[String]): Seq[Path] =
     input.split(File.pathSeparator).filter(_.nonEmpty).flatMap { elem =>
+      val processedElem = {
+        var value            = elem
+        var matcher: Matcher = null
+
+        while ({
+          matcher = propertyRegex.matcher(value)
+          matcher.find()
+        }) {
+          val start    = matcher.start(0)
+          val end      = matcher.end(0)
+          val subKey   = value.substring(start + 2, end - 1)
+          val subValue = getProperty(subKey).getOrElse("")
+          value = value.substring(0, start) + subValue + value.substring(end)
+        }
+
+        value
+      }
       def allJarsOf(dir: Path): Seq[Path] =
         Files.list(dir)
           .iterator
@@ -19,16 +41,16 @@ object ClassPathUtil {
             name.substring(name.length() - ".jar".length).equalsIgnoreCase(".jar")
           }
           .toVector
-      if (elem.endsWith("/*")) {
-        val dir = Paths.get(elem.stripSuffix("/*"))
+      if (processedElem.endsWith("/*")) {
+        val dir = Paths.get(processedElem.stripSuffix("/*"))
         allJarsOf(dir)
       }
-      else if (elem.endsWith("/*.jar")) {
-        val dir = Paths.get(elem.stripSuffix("/*.jar"))
+      else if (processedElem.endsWith("/*.jar")) {
+        val dir = Paths.get(processedElem.stripSuffix("/*.jar"))
         allJarsOf(dir)
       }
       else
-        Seq(Paths.get(elem))
+        Seq(Paths.get(processedElem))
     }
 
 }