chores: Add build server debug config (microsoft#1486)

.vscode/launch.json

@@ -81,6 +81,26 @@
         "order": 2
       }
     },
+    {
+      "name": "Debug Extension & Build Server",
+      "type": "extensionHost",
+      "request": "launch",
+      "runtimeExecutable": "${execPath}",
+      "args": [
+        "--extensionDevelopmentPath=${workspaceFolder}/extension"
+      ],
+      "outFiles": [
+        "${workspaceFolder}/extension/dist/**/*.js"
+      ],
+      "preLaunchTask": "Gradle: Build",
+      "presentation": {
+        "group": "debug",
+        "order": 3
+      },
+      "env": {
+        "DEBUG_GRADLE_BUILD_SERVER":"true"
+      },
+    },
     {
       "name": "Debug Language Server: Launch Extension",
       "type": "extensionHost",

CONTRIBUTING.md

@@ -40,6 +40,25 @@ The extension uses a Gradle plugin (`com.microsoft.gradle.GradlePlugin`) to get
 
 > Note: There is a known issue that when the Gradle project stores in a sub-folder of the root folder, the `Attach to Gradle Plugin` will fail to attach. See [#1237](https://github.com/microsoft/vscode-gradle/issues/1237).
 
+## Debugging Gradle Build Server
+
+To debug the Extension with the [Gradle Build Server](https://github.com/microsoft/build-server-for-gradle), follow these steps:
+
+1. Open the `extension/build-server-for-gradle` directory, which you should have [imported previously](#build-gradle-project-importer) as a separate project.
+2. In the `.vscode/launch.json` of the build-server-for-gradle project, ensure you have the following configuration to attach the debugger:
+   ```json
+   {
+     "type": "java",
+     "name": "Attach to Gradle Build Server",
+     "request": "attach",
+     "hostName": "localhost",
+     "port": "8989",
+     "projectName": "server"
+   }
+   ```
+3. In your main project (vscode-gradle), start the `Debug Extension & Build Server` launch configuration.
+4. In the build-server-for-gradle project, start the `Attach to Gradle Build Server` launch configuration.
+
 ## Debugging Gradle Language Server (editing feature related)
 
 1. Run vscode launch configuration `Debug Language Server: Launch Extension`.

extension/jdtls.ext/com.microsoft.gradle.bs.importer/src/com/microsoft/gradle/bs/importer/ImporterPlugin.java

@@ -3,6 +3,8 @@
 import java.io.File;
 import java.io.IOException;
 import java.nio.file.Paths;
+import java.util.ArrayList;
+import java.util.List;
 import java.util.Map;
 import java.util.Optional;
 import java.util.concurrent.ConcurrentHashMap;
@@ -84,17 +86,20 @@ public static BuildServerConnection getBuildServerConnection(IPath rootPath) thr
 
         String pluginPath = getBuildServerPluginPath();
 
-        ProcessBuilder build = new ProcessBuilder(
-                javaExecutablePath,
-                "--add-opens=java.base/java.lang=ALL-UNNAMED",
-                "--add-opens=java.base/java.io=ALL-UNNAMED",
-                "--add-opens=java.base/java.util=ALL-UNNAMED",
-                "-Dplugin.dir=" + pluginPath,
-                "-cp",
-                String.join(getClasspathSeparator(), classpaths),
-                "com.microsoft.java.bs.core.Launcher"
-        );
-
+        List<String> command = new ArrayList<>();
+        command.add(javaExecutablePath);
+        if (Boolean.parseBoolean(System.getenv("DEBUG_GRADLE_BUILD_SERVER"))) {
+            command.add("-agentlib:jdwp=transport=dt_socket,server=y,suspend=y,address=8989");
+        }
+        command.add("--add-opens=java.base/java.lang=ALL-UNNAMED");
+        command.add("--add-opens=java.base/java.io=ALL-UNNAMED");
+        command.add("--add-opens=java.base/java.util=ALL-UNNAMED");
+        command.add("-Dplugin.dir=" + pluginPath);
+        command.add("-cp");
+        command.add(String.join(getClasspathSeparator(), classpaths));
+        command.add("com.microsoft.java.bs.core.Launcher");
+
+        ProcessBuilder build = new ProcessBuilder(command);
         try {
             Process process = build.start();
             BuildClient client = new GradleBuildClient();