defaultHubStateFile function
The default hub state file (~/.dap/hub.json) — the hub's master
secret (the "hub password") and enrolled per-client secrets live here
so fa hub serve restarts keep both. DAP_HUB_STATE_FILE (from
environment) wins outright; home overrides ~ (test seam).
Implementation
File defaultHubStateFile({String? home, Map<String, String>? environment}) {
final env = environment ?? Platform.environment;
final override = env['DAP_HUB_STATE_FILE'];
if (override != null && override.isNotEmpty) return File(override);
final root =
home ?? env['HOME'] ?? env['USERPROFILE'] ?? Directory.current.path;
return File('${root.endsWith('/') ? root : '$root/'}.dap/hub.json');
}