PatchbayCatalogDigest.ofCommands constructor

PatchbayCatalogDigest.ofCommands(Object? commands)

Digests the commands array of a catalog.

commands is whatever the catalog carries under that key; anything that is not a list digests as an empty surface, because an App that declares no commands and an App whose commands key is absent have the same declared surface. A malformed list never reaches here: the host validates the array before serving it, and a violated catalog gets no digest at all.

Entries are canonicalised individually and then sorted as strings, so the digest is independent of the order the composition root happened to register in — reordering a registration list is not a capability change.

Implementation

factory PatchbayCatalogDigest.ofCommands(Object? commands) {
  final List<Object?> rows = commands is List<Object?>
      ? commands
      : const <Object?>[];
  final List<String> canonical = <String>[
    for (final Object? row in rows) patchbayCanonicalJson(row),
  ]..sort();
  return PatchbayCatalogDigest(
    algorithm: patchbayDigestAlgorithmSha256,
    covers: const <String>[patchbayCatalogDigestScopeCommands],
    value: crypto.sha256
        .convert(utf8.encode('[${canonical.join(',')}]'))
        .toString(),
  );
}