From 2884775f29b2d38a7ca0991d1b6f4392c2de1814 Mon Sep 17 00:00:00 2001
From: Tomasz Godzik <tgodzik@virtuslab.com>
Date: Mon, 13 Feb 2023 19:04:26 +0100
Subject: [PATCH] docs: Add more info about how to discover main class to run

---
 docs/integrations/debug-adapter-protocol.md   | 29 +++++++++++++++++--
 .../meta/internal/metals/ServerCommands.scala | 15 ++++++++++
 .../internal/metals/debug/DebugProvider.scala |  2 +-
 3 files changed, 42 insertions(+), 4 deletions(-)

diff --git a/docs/integrations/debug-adapter-protocol.md b/docs/integrations/debug-adapter-protocol.md
index 39c03910788..3e0be8cbcf0 100644
--- a/docs/integrations/debug-adapter-protocol.md
+++ b/docs/integrations/debug-adapter-protocol.md
@@ -33,8 +33,8 @@ command.
 Starting a Debug Adapter Protocol session might take some time, since it needs
 to set up all the neccesary utilities for debugging. Metals also provides a
 `shellCommand` field, which will be present in the command attached to the run
-main methods code lenses. This field can be used to simply run the process quickly
-without the debugging capabilities.
+main methods code lenses. This field can be used to simply run the process
+quickly without the debugging capabilities.
 
 If you can't or won't support DAP, you can use the `runProvider` instead of
 `debugProvider `option in the initialization options sent from the editor to the
@@ -118,11 +118,34 @@ keys that can be sent as well with the same format as above.
 
 ```json
 {
-  "path": "file:///path/to/my/file.scala"
+  "path": "file:///path/to/my/file.scala",
   "runType": "testTarget"
 }
 ```
 
+Instead of `debug-adapter-start` if you only want to get data about the command
+to run you can use `discover-jvm-run-command`, which takes the same json as
+above, but instead of starting the DAP session it will return the
+`DebugSessionParams` object containing targets that this main class can be run
+for along with the data about the main class which will take form of:
+
+```json
+{
+  "targets": ["id1"],
+  "dataKind": "scala-main-class",
+  "data": {
+    "class": "Foo",
+    "arguments": [],
+    "jvmOptions": [],
+    "environmentVariables": [],
+    "shellCommand": "java ..."
+  }
+}
+```
+
+where `shellCommand` will be the exact command to run if you want to run it on
+your own without DAP.
+
 ### Wiring it all together
 
 No matter which method you use, you still need to connect the debug adapter
diff --git a/metals/src/main/scala/scala/meta/internal/metals/ServerCommands.scala b/metals/src/main/scala/scala/meta/internal/metals/ServerCommands.scala
index 9c985ff74aa..68508b661dd 100644
--- a/metals/src/main/scala/scala/meta/internal/metals/ServerCommands.scala
+++ b/metals/src/main/scala/scala/meta/internal/metals/ServerCommands.scala
@@ -132,6 +132,21 @@ object ServerCommands {
        |    "runType": "run"
        |}
        |```
+       |
+       |Response:
+       |```json
+       |{
+       |  "targets": ["id1"],
+       |  "dataKind": "scala-main-class",
+       |  "data": {
+       |    "class": "Foo",
+       |    "arguments": [],
+       |    "jvmOptions": [],
+       |    "environmentVariables": [],
+       |    "shellCommand": "java ..."
+       |  }
+       |}
+       |```
        |""".stripMargin,
   )
 
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
index 45655588194..65354bb4195 100644
--- a/metals/src/main/scala/scala/meta/internal/metals/debug/DebugProvider.scala
+++ b/metals/src/main/scala/scala/meta/internal/metals/debug/DebugProvider.scala
@@ -41,6 +41,7 @@ import scala.meta.internal.metals.ScalaTestSuitesDebugRequest
 import scala.meta.internal.metals.SourceMapper
 import scala.meta.internal.metals.StacktraceAnalyzer
 import scala.meta.internal.metals.StatusBar
+import scala.meta.internal.metals.UserConfiguration
 import scala.meta.internal.metals.clients.language.MetalsLanguageClient
 import scala.meta.internal.metals.clients.language.MetalsQuickPickItem
 import scala.meta.internal.metals.clients.language.MetalsQuickPickParams
@@ -64,7 +65,6 @@ 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.