Linux: process-group kill and full command names from ps

dotnet watch is spawned detached on Unix so stop() can signal the whole
group; ps output uses args instead of the 15-character comm field.

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_0169iPWwKHZoBTNN9qwXiwqk

README.md

@@ -250,6 +250,15 @@ honoured, so both extensions use the same SDK.
   terminal and the *Problems* panel (`$msCompile`).
 - The *.NET Solution* output channel logs every `dotnet` invocation.
 
+## Platforms
+
+Windows, Linux and macOS. The only platform-specific code is around processes: the
+apphost is `MyGame.Editor.exe` on Windows and `MyGame.Editor` elsewhere; the process
+list comes from `wmic` (or PowerShell's CIM query where wmic is gone) on Windows and
+`ps -eo pid,ppid,args` elsewhere; and stopping hot reload uses `taskkill /T` on Windows
+and a process-group signal on Unix, where `dotnet watch` is started detached for that
+reason.
+
 ## Development
 
 ```

src/hotreload/processes.ts

@@ -16,7 +16,9 @@ export interface ProcessInfo {
 export async function listProcesses(): Promise<ProcessInfo[]> {
     if (process.platform !== 'win32') {
         try {
-            return parsePs(await capture('ps', ['-eo', 'pid=,ppid=,comm=']));
+            // args rather than comm: comm is the kernel's 15-character name, which would
+            // cut "MyGame.Editor.Tools" short and never match the assembly name.
+            return parsePs(await capture('ps', ['-eo', 'pid=,ppid=,args=']));
         } catch {
             return [];
         }
@@ -67,12 +69,18 @@ export function parseWmicCsv(text: string): ProcessInfo[] {
     return processes;
 }
 
+/** Parses `ps -eo pid=,ppid=,args=`: the name is the basename of the command, without its arguments. */
 export function parsePs(text: string): ProcessInfo[] {
     const processes: ProcessInfo[] = [];
     for (const line of text.split(/\r?\n/)) {
-        const match = /^\s*(\d+)\s+(\d+)\s+(.*\S)\s*$/.exec(line);
+        const match = /^\s*(\d+)\s+(\d+)\s+(\S+)/.exec(line);
         if (match) {
-            processes.push({ pid: Number(match[1]), parentPid: Number(match[2]), name: match[3] });
+            const command = match[3].replace(/^\[|\]$/g, ''); // kernel threads show as [name]
+            processes.push({
+                pid: Number(match[1]),
+                parentPid: Number(match[2]),
+                name: command.slice(command.lastIndexOf('/') + 1),
+            });
         }
     }
     return processes;

src/hotreload/session.ts

@@ -111,6 +111,10 @@ export class HotReloadSession implements vscode.Disposable {
             cwd: spec.cwd,
             env,
             windowsHide: true,
+            // On Unix a detached child leads its own process group, which is what lets
+            // stop() kill the watcher *and* the application below it with one signal.
+            // Windows has taskkill /T for that and does not need it.
+            detached: process.platform !== 'win32',
         });
 
         this.child.stdout?.on('data', chunk => this.consume(String(chunk)));

src/test/unit/hotreload.test.ts

@@ -44,6 +44,9 @@ suite('process lookup', () => {
         const csv = '\r\nNode,Name,ParentProcessId,ProcessId\r\nPC,dotnet.exe,1,100\r\nPC,MyGame.Editor.exe,100,103\r\n';
         assert.deepStrictEqual(parseWmicCsv(csv), [
             { pid: 100, parentPid: 1, name: 'dotnet.exe' }, { pid: 103, parentPid: 100, name: 'MyGame.Editor.exe' }]);
+        assert.deepStrictEqual(parsePs('  100     1 /usr/bin/dotnet watch run\n  103   100 /home/u/MyGame/Bin/MyGame.Editor --flag\n    2     0 [kthreadd]\n'), [
+            { pid: 100, parentPid: 1, name: 'dotnet' }, { pid: 103, parentPid: 100, name: 'MyGame.Editor' },
+            { pid: 2, parentPid: 0, name: 'kthreadd' }]);
         assert.deepStrictEqual(parsePs('  100     1 dotnet\n  103   100 MyGame.Editor\n'), [
             { pid: 100, parentPid: 1, name: 'dotnet' }, { pid: 103, parentPid: 100, name: 'MyGame.Editor' }]);
     });