fix: detect main module under PM2

src/infra/is-main.ts

@@ -0,0 +1,63 @@
+import fs from "node:fs";
+import path from "node:path";
+
+type IsMainModuleOptions = {
+  currentFile: string;
+  argv?: string[];
+  env?: NodeJS.ProcessEnv;
+  cwd?: string;
+};
+
+function normalizePathCandidate(
+  candidate: string | undefined,
+  cwd: string,
+): string | undefined {
+  if (!candidate) return undefined;
+
+  const resolved = path.resolve(cwd, candidate);
+  try {
+    return fs.realpathSync.native(resolved);
+  } catch {
+    return resolved;
+  }
+}
+
+export function isMainModule({
+  currentFile,
+  argv = process.argv,
+  env = process.env,
+  cwd = process.cwd(),
+}: IsMainModuleOptions): boolean {
+  const normalizedCurrent = normalizePathCandidate(currentFile, cwd);
+  const normalizedArgv1 = normalizePathCandidate(argv[1], cwd);
+
+  if (
+    normalizedCurrent &&
+    normalizedArgv1 &&
+    normalizedCurrent === normalizedArgv1
+  ) {
+    return true;
+  }
+
+  // PM2 runs the script via an internal wrapper; `argv[1]` points at the wrapper.
+  // PM2 exposes the actual script path in `pm_exec_path`.
+  const normalizedPmExecPath = normalizePathCandidate(env.pm_exec_path, cwd);
+  if (
+    normalizedCurrent &&
+    normalizedPmExecPath &&
+    normalizedCurrent === normalizedPmExecPath
+  ) {
+    return true;
+  }
+
+  // Fallback: basename match (relative paths, symlinked bins).
+  if (
+    normalizedCurrent &&
+    normalizedArgv1 &&
+    path.basename(normalizedCurrent) === path.basename(normalizedArgv1)
+  ) {
+    return true;
+  }
+
+  return false;
+}