feature: Add the possibility to discover the main class to run

Previously, the only possibility to discover the main class to run was to try and run it. Now, we can also ask for it so that client editor can use that shell command.
scalameta · Feb 10, 2023 · 966d799 · 966d799
1 parent df320fe
commit 966d799
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diff --git a/metals/src/main/scala/scala/meta/internal/metals/MetalsLspService.scala b/metals/src/main/scala/scala/meta/internal/metals/MetalsLspService.scala
@@ -676,6 +676,7 @@ class MetalsLspService(
       compilers,
       statusBar,
       sourceMapper,
+      () => userConfig,
     )
   )
 
@@ -1825,6 +1826,10 @@ class MetalsLspService(
             Option(params.uri).map(_.toAbsolutePath)
           )
         }.asJavaObject
+      case ServerCommands.DiscoverMainClasses(unresolvedParams) =>
+        debugProvider
+          .runCommandDiscovery(unresolvedParams)
+          .asJavaObject
       case ServerCommands.RunScalafix(params) =>
         val uri = params.getTextDocument().getUri()
         scalafixProvider

diff --git a/metals/src/main/scala/scala/meta/internal/metals/ServerCommands.scala b/metals/src/main/scala/scala/meta/internal/metals/ServerCommands.scala
@@ -118,6 +118,23 @@ object ServerCommands {
        |""".stripMargin,
   )
 
+  val DiscoverMainClasses = new ParametrizedCommand[DebugDiscoveryParams](
+    "discover-jvm-run-command",
+    "Discover main classes to run and return the object",
+    """|Gets the DebugSession object that also contains a command to run in shell based 
+       |on JVM environment including classpath, jvmOptions and environment parameters.
+       |""".stripMargin,
+    """|DebugUnresolvedTestClassParams object
+       |Example:
+       |```json
+       |{
+       |    "path": "path/to/file.scala",
+       |    "runType": "run"
+       |}
+       |```
+       |""".stripMargin,
+  )
+
   /** If uri is null discover all test suites, otherwise discover testcases in file */
   final case class DiscoverTestParams(
       @Nullable uri: String = null
@@ -666,6 +683,7 @@ object ServerCommands {
       CleanCompile,
       ConvertToNamedArguments,
       CopyWorksheetOutput,
+      DiscoverMainClasses,
       DiscoverTestSuites,
       ExtractMemberDefinition,
       GenerateBspConfig,

diff --git a/metals/src/main/scala/scala/meta/internal/metals/debug/DebugProvider.scala b/metals/src/main/scala/scala/meta/internal/metals/debug/DebugProvider.scala
@@ -64,6 +64,7 @@ import com.google.common.net.InetAddresses
 import com.google.gson.JsonElement
 import org.eclipse.lsp4j.MessageParams
 import org.eclipse.lsp4j.MessageType
+import scala.meta.internal.metals.UserConfiguration
 
 /**
  * @param supportsTestSelection test selection hasn't been defined in BSP spec yet.
@@ -83,6 +84,7 @@ class DebugProvider(
     compilers: Compilers,
     statusBar: StatusBar,
     sourceMapper: SourceMapper,
+    userConfig: () => UserConfiguration,
 ) extends Cancelable {
 
   import DebugProvider._
@@ -405,6 +407,43 @@ class DebugProvider(
     }
   }
 
+  /**
+   * Tries to discover the main class to run and returns
+   * DebugSessionParams that contains the shellCommand field.
+   * This is used so that clients can easily run the full command
+   * if they want.
+   */
+  def runCommandDiscovery(
+      unresolvedParams: DebugDiscoveryParams
+  )(implicit ec: ExecutionContext): Future[b.DebugSessionParams] = {
+    debugDiscovery(unresolvedParams).map(enrichWithMainShellCommand)
+  }
+
+  private def enrichWithMainShellCommand(
+      params: b.DebugSessionParams
+  ): b.DebugSessionParams = {
+    params.getData() match {
+      case json: JsonElement
+          if params.getDataKind == b.DebugSessionParamsDataKind.SCALA_MAIN_CLASS =>
+        json.as[b.ScalaMainClass] match {
+          case Success(main) if params.getTargets().size > 0 =>
+            val updatedData = buildTargetClasses.jvmRunEnvironment
+              .get(params.getTargets().get(0))
+              .zip(userConfig().usedJavaBinary) match {
+              case None =>
+                main.toJson
+              case Some((env, javaHome)) =>
+                ExtendedScalaMainClass(main, env, javaHome, workspace).toJson
+            }
+            params.setData(updatedData)
+          case _ =>
+        }
+
+      case _ =>
+    }
+    params
+  }
+
   /**
    * Given fully unresolved params this figures out the runType that was passed
    * in and then discovers either the main methods for the build target the