auditEntryPointRules function

List<SeamViolation> auditEntryPointRules(String root, List<EntryPointRule> rules, { required String seam, })

Checks every rule in rules against the packages under root, reporting each crossing under seam.

A declared entry point that does not exist is a violation rather than a pass: a renamed or deleted entry point must fail here, not pass by having nothing to walk.

Implementation

List<SeamViolation> auditEntryPointRules(
  String root,
  List<EntryPointRule> rules, {
  required String seam,
}) {
  final violations = <SeamViolation>[];
  for (final rule in rules) {
    final file = p.join(root, rule.package, rule.entryPoint);
    if (!File(file).existsSync()) {
      // A renamed or deleted entry point must fail here rather than pass by
      // having nothing to walk.
      violations.add(
        SeamViolation(
          seam,
          '${rule.package}: declared entry point ${rule.entryPoint} does not '
          'exist — the rule cannot be checked, so it is a violation.',
        ),
      );
      continue;
    }
    final uris = externalImportsOf(file);
    for (final banned in rule.bannedUris) {
      if (uris.contains(banned)) {
        violations.add(
          SeamViolation(
            seam,
            '${rule.package}/${rule.entryPoint} reaches "$banned". The package '
            'is permitted; that entry point of it is not.',
          ),
        );
      }
    }
    final names = reachableNamesOf(file);
    for (final banned in rule.banned) {
      if (names.contains(banned)) {
        violations.add(
          SeamViolation(
            seam,
            '${rule.package}/${rule.entryPoint} reaches "$banned", which that '
            'entry point must not link.',
          ),
        );
      }
    }
    for (final needed in rule.required) {
      if (!names.contains(needed)) {
        violations.add(
          SeamViolation(
            seam,
            '${rule.package}/${rule.entryPoint} no longer reaches "$needed" — '
            'the seam it exists to expose is gone, so the matching ban '
            'elsewhere now passes vacuously.',
          ),
        );
      }
    }
  }
  return violations;
}