waitUntilReady method

@override Future<void> waitUntilReady(WaitStrategyTarget target)

Runs test -f <filePath> inside the container on each poll cycle.

On timeout, a diagnostic ls of the parent directory is run inside the container and included in the TimeoutException message.

Implementation

@override
Future<void> waitUntilReady(WaitStrategyTarget target) async {
  final ready = await poll(() async {
    final (exitCode, _) = await target.exec(['test', '-f', filePath]);
    return exitCode == 0;
  });

  if (!ready) {
    // Best-effort: list the parent directory inside the container for diagnostics.
    String listing = '(unavailable)';
    try {
      // p.dirname handles edge cases such as '/ready' → '/' correctly.
      final parent = p.dirname(filePath);
      final (_, output) = await target.exec(['ls', '-la', parent]);
      listing = String.fromCharCodes(output);
    } catch (_) {
      // Diagnostic only — ignore errors.
    }
    throw TimeoutException(
      'File $filePath not found in container within $startupTimeout. '
      'Parent directory contents: $listing',
    );
  }
}