halkyon/packages/halkyon_base_server/test/integration/register/register_test.dart

import 'dart:convert';
import 'dart:typed_data';

import 'package:clock/clock.dart';
import 'package:halkyon_base_server/base.dart';
import 'package:halkyon_base_server/src/register/deletion_notices.dart';
import 'package:halkyon_base_server/src/register/instance_api.dart';
import 'package:halkyon_base_server/src/register/register_protocol.dart';
import 'package:halkyon_base_server/src/register/remote_register.dart';
import 'package:http/http.dart' as http;
import 'package:http/testing.dart';
import 'package:serverpod/serverpod.dart';
import 'package:serverpod_auth_idp_server/core.dart';
import 'package:test/test.dart';

import '../support/fixtures.dart';
import '../support/password_device.dart';
import '../test_tools/serverpod_test_tools.dart';

const _secret = 'a shared secret only the instance knows';
final _todo = Uri.parse('http://todo.test:8082');
final _train = Uri.parse('http://train.test:8082');

/// Keeps every code mailed, in place of a mail service.
final class _Mailbox implements CodeMailer {
  final sent = <({String to, String code})>[];

  @override
  Future<void> send(
    Session session, {
    required String to,
    required String code,
    required String language,
  }) async => sent.add((to: to, code: code));

  @override
  Future<void> sendResetNotice(
    Session session, {
    required String to,
    required AccountResetKind kind,
    required DateTime takesEffectAt,
    required String language,
  }) async {}

  @override
  Future<void> sendCodesWaitNotice(
    Session session, {
    required String to,
    required DateTime until,
    required String language,
  }) async {}

  String codeFor(String address) =>
      sent.lastWhere((mail) => mail.to == address).code;
}

/// The members as the register tells them, each answering as [answers]
/// says (confirming by default).
final class _Members implements MemberNotifier {
  final told = <(Uri, UuidValue)>[];

  /// The sessions ended they were told of: member, account, moment, kept.
  final sessionsTold = <(Uri, UuidValue, DateTime, UuidValue?)>[];
  bool Function(Uri member) answers = (_) => true;

  @override
  Future<bool> accountGone(Uri member, UuidValue account) async {
    told.add((member, account));
    return answers(member);
  }

  @override
  Future<bool> sessionsEnded(
    Uri member,
    UuidValue account, {
    required DateTime endedBefore,
    UuidValue? keepSession,
  }) async {
    sessionsTold.add((member, account, endedBefore, keepSession));
    return answers(member);
  }
}

void main() {
  withServerpod(
    'The register answering its members',
    // Mailing codes counts attempts in transactions of their own
    // (Serverpod's rate limiter), which the test's rollback can't wrap.
    rollbackDatabase: RollbackDatabase.disabled,
    (sessionBuilder, endpoints) {
      late Session session;
      late Serverpod pod;
      late _Mailbox mailbox;
      late _Members members;

      /// The register as a member's server asks it, over HTTP into this
      /// server's answers.
      late RemoteRegister remote;

      /// Identified, signing in with ben@example.org and GitHub 1001.
      late UuidValue ben;

      setUp(() async {
        useBase(sessionBuilder, accounts: HoldsRegister(members: [_todo]));
        session = sessionBuilder.build();
        pod = session.serverpod;
        await _deleteAll(session);
        useInstanceSecret(pod, _secret);
        mailbox = _Mailbox();
        EmailCodes.of(pod).mailer = mailbox;
        members = _Members();
        MemberNotifier.use(pod, members);
        remote = RemoteRegister(
          Uri.parse('http://learn.test:8082'),
          secret: _secret,
          client: () => MockClient((request) async {
            final answer = await answerMember(
              session,
              request.url.pathSegments.last,
              request.body,
              authorization: request.headers['authorization'],
            );
            return http.Response.bytes(
              utf8.encode(jsonEncode(answer.body)),
              answer.status,
            );
          }),
        );
        ben = (await AuthServices.instance.authUsers.create(
          session,
          scopes: {identified},
        )).id;
        await EmailIdentity.db.insertRow(
          session,
          EmailIdentity(
            authUserId: ben,
            addressHash: addressHash(pod, 'ben@example.org'),
            createdAt: clock.now(),
          ),
        );
        await GitHubAccount.db.insertRow(
          session,
          GitHubAccount(userIdentifier: '1001', authUserId: ben),
        );
      });
      tearDown(() async {
        EmailCodes.of(pod).mailer = null;
        MemberNotifier.use(pod, null);
        useInstanceSecret(pod, null);
        await _deleteAll(sessionBuilder.build());
      });

      Future<InstanceAnswer> ask(
        String operation,
        Map<String, Object?> arguments, {
        String? authorization = 'Bearer $_secret',
      }) => answerMember(
        session,
        operation,
        jsonEncode(arguments),
        authorization: authorization,
      );

      Matcher refused(Object reason) => throwsA(
        isA<Exception>().having(
          (error) => refusalJson(error)?['reason'],
          'reason',
          (reason as Enum).name,
        ),
      );

      group('refuses', () {
        test('a call without the instance secret, with a wrong one or in '
            'another scheme, doing nothing', () async {
          for (final authorization in [
            null,
            '',
            'Bearer',
            'Bearer ',
            'Bearer not the secret',
            'Bearer $_secret ',
            'Basic $_secret',
            _secret,
          ]) {
            final answer = await ask(RegisterOperation.deleteAccount, {
              'person': ben.uuid,
            }, authorization: authorization);
            expect(answer.status, 401, reason: authorization);
          }
          expect(await AuthUser.db.findById(session, ben), isNotNull);
        });

        test(
          'every call on a register without a secret, whatever is sent',
          () async {
            useInstanceSecret(pod, null);

            for (final authorization in [null, 'Bearer ', 'Bearer null']) {
              final answer = await ask(RegisterOperation.deleteAccount, {
                'person': ben.uuid,
              }, authorization: authorization);
              expect(answer.status, 401, reason: authorization);
            }
            expect(await AuthUser.db.findById(session, ben), isNotNull);
          },
        );

        test('register calls on a member, which holds no register', () async {
          useBase(
            sessionBuilder,
            accounts: MemberOfRegister(Uri.parse('http://learn.test:8082')),
          );

          final answer = await ask(RegisterOperation.knownAccounts, {
            'people': [ben.uuid],
          });

          expect(answer.status, 404);
        });

        test('what it cannot read, and operations it does not know', () async {
          for (final body in ['', 'not JSON', '[]', '"ben"', 'null']) {
            final answer = await answerMember(
              session,
              RegisterOperation.knownAccounts,
              body,
              authorization: 'Bearer $_secret',
            );
            expect(answer.status, 400, reason: body);
          }
          for (final arguments in <Map<String, Object?>>[
            {},
            {'people': 'not a list'},
            {
              'people': [1, 2],
            },
            {
              'people': ['not an id'],
            },
          ]) {
            final answer = await ask(
              RegisterOperation.knownAccounts,
              arguments,
            );
            expect(answer.status, 400, reason: '$arguments');
          }
          expect(
            (await ask(RegisterOperation.deleteAccount, {
              'person': 'not an id',
            })).status,
            400,
          );
          expect((await ask('drop-everything', {})).status, 404);
          expect(await AuthUser.db.findById(session, ben), isNotNull);
        });
      });

      group('profiles', () {
        test('are saved, read and fixed for a member as for this server, '
            'the same handle never twice', () async {
          final anna = const Uuid().v7obj();

          final saved = await remote.saveProfile(
            session,
            anna,
            handle: 'Anna',
            displayName: ' Anna ',
            bio: 'Learning Greek.',
            links: ['https://anna.example.org'],
          );

          expect(saved.handle, 'Anna');
          expect(saved.displayName, 'Anna');
          expect(
            (await remote.profileOf(session, anna))!.toJson(),
            saved.toJson(),
          );
          expect((await profileOf(session, anna))!.toJson(), saved.toJson());
          expect(
            (await remote.profileByHandle(session, 'anna'))!.toJson(),
            saved.toJson(),
          );
          expect(await remote.personWithHandle(session, 'ANNA'), anna);
          expect((await remote.profilesOf(session, {anna, ben})).keys, [anna]);
          expect(await remote.checkHandle(session, anna, 'Anna'), isNull);
          expect(
            await remote.checkHandle(session, ben, 'anna'),
            ProfileRefusal.handleTaken,
          );
          await expectLater(
            remote.saveProfile(
              session,
              ben,
              handle: 'anna',
              displayName: '',
              bio: '',
              links: const [],
            ),
            refused(ProfileRefusal.handleTaken),
          );

          await remote.fixHandle(session, anna);

          expect((await remote.profileOf(session, anna))!.handleFixed, isTrue);
          await expectLater(
            remote.removeProfile(session, anna),
            refused(ProfileRefusal.published),
          );
        });

        test('missing are said to be so', () async {
          final nobody = const Uuid().v7obj();

          expect(await remote.profileOf(session, nobody), isNull);
          expect(await remote.profileByHandle(session, 'nobody'), isNull);
          expect(await remote.personWithHandle(session, 'nobody'), isNull);
          expect(await remote.profilesOf(session, {nobody}), isEmpty);
          await expectLater(
            remote.removeAvatar(session, nobody),
            throwsA(isA<ProfileNotFoundException>()),
          );
          await expectLater(
            remote.checkLinks(session, nobody),
            throwsA(isA<ProfileNotFoundException>()),
          );
        });
      });

      group('email sign-in', () {
        test('is offered as the register offers it', () async {
          expect(await remote.emailSignInOffered(session), isTrue);
          EmailCodes.of(pod).mailer = null;
          expect(await remote.emailSignInOffered(session), isFalse);
        });

        test("counts the codes a member asks for by its device's network, "
            "not the member's", () async {
          for (var i = 0; i < 10; i++) {
            await remote.sendSignInCode(
              session,
              address: 'person$i@example.org',
              language: 'en',
              network: '203.0.113.7',
            );
          }

          await expectLater(
            remote.sendSignInCode(
              session,
              address: 'person10@example.org',
              language: 'en',
              network: '203.0.113.7',
            ),
            refused(EmailSignInRefusal.tooManyCodes),
          );
          await remote.sendSignInCode(
            session,
            address: 'person10@example.org',
            language: 'en',
            network: '198.51.100.4',
          );
          expect(mailbox.sent, hasLength(11));
        });

        test("a code proves the address for a member's password, and a "
            'wrong one refuses it, keeping nothing', () async {
          usePasswordKeys(pod, testPasswordKeys);
          addTearDown(() => usePasswordKeys(pod, null));
          final device = await PasswordDevice.make();
          final annaOnTodo = const Uuid().v7obj();
          final request = await remote.sendSignInCode(
            session,
            address: 'Anna@example.org',
            language: 'de',
            network: '203.0.113.7',
          );

          await expectLater(
            remote.setPassword(
              session,
              person: annaOnTodo,
              setup: device.setup(),
              request: request,
              code: 'AAAA-AAAA',
            ),
            refused(EmailSignInRefusal.wrongCode),
          );
          expect(await AuthUser.db.findById(session, annaOnTodo), isNull);
          await remote.setPassword(
            session,
            person: annaOnTodo,
            setup: device.setup(),
            request: request,
            code: mailbox.codeFor('anna@example.org'),
          );
          expect(
            (await AuthUser.db.findById(session, annaOnTodo))!.scopeNames,
            contains(identified.name),
          );
          expect(await remote.knownAccounts(session, {annaOnTodo, ben}), {
            annaOnTodo,
            ben,
          });
        });
      });

      group('GitHub', () {
        test("links a member's person, who becomes an account under the "
            'same ID, found by it afterwards', () async {
          final annaOnTodo = const Uuid().v7obj();

          await remote.linkGitHub(
            session,
            person: annaOnTodo,
            gitHubUserId: '2002',
          );

          expect(await remote.accountWithGitHub(session, '2002'), annaOnTodo);
          expect(await remote.accountWithGitHub(session, '1001'), ben);
          expect(await remote.accountWithGitHub(session, '3003'), isNull);
          expect(
            (await AuthUser.db.findById(session, annaOnTodo))!.scopeNames,
            contains(identified.name),
          );
        });

        test(
          "refuses another person's GitHub account, keeping nothing",
          () async {
            final annaOnTodo = const Uuid().v7obj();

            await expectLater(
              remote.linkGitHub(
                session,
                person: annaOnTodo,
                gitHubUserId: '1001',
              ),
              refused(GitHubSignInRefusal.takenByAnotherPerson),
            );
            expect(await AuthUser.db.findById(session, annaOnTodo), isNull);
          },
        );
      });

      group('passwords (ADR 0017)', () {
        late DateTime now;
        Future<T> atNow<T>(Future<T> Function() body) =>
            withClock(Clock(() => now), body);

        setUp(() {
          usePasswordKeys(pod, testPasswordKeys);
          now = DateTime.utc(2026, 10, 20, 12);
        });

        test('are offered as the register offers them', () async {
          expect(await remote.passwordSignInOffered(session), isTrue);
          usePasswordKeys(pod, null);
          expect(await remote.passwordSignInOffered(session), isFalse);
          await expectLater(
            remote.beginPasswordSignIn(
              session,
              address: 'ben@example.org',
              network: '203.0.113.7',
            ),
            refused(PasswordRefusal.unavailable),
          );
        });

        test("cross for a member's device, every operation, with what the "
            'register refuses', () async {
          final device = await PasswordDevice.make();
          await atNow(() async {
            final annaOnTodo = const Uuid().v7obj();
            final request = await remote.sendSignInCode(
              session,
              address: 'anna@example.org',
              language: 'en',
              network: '203.0.113.7',
            );
            await remote.setPassword(
              session,
              person: annaOnTodo,
              setup: device.setup(),
              request: request,
              code: mailbox.codeFor('anna@example.org'),
            );
            expect(
              (await AuthUser.db.findById(session, annaOnTodo))!.scopeNames,
              contains(identified.name),
            );
            await expectLater(
              remote.setPassword(
                session,
                person: ben,
                setup: device.setup().copyWith(salt: ByteData(3)),
              ),
              refused(PasswordRefusal.invalidSetup),
            );

            final enrolment = await remote.enrolAuthenticator(
              session,
              person: annaOnTodo,
              name: 'Phone',
              label: 'anna@example.org',
            );
            final codes = await remote.confirmAuthenticator(
              session,
              person: annaOnTodo,
              authenticator: enrolment.authenticator,
              code: codeOf(enrolment),
            );
            expect(codes, hasLength(recoveryCodeCount));
            expect(
              (await remote.authenticatorsOf(session, annaOnTodo)).single.id,
              enrolment.authenticator,
            );
            final spare = await remote.enrolAuthenticator(
              session,
              person: annaOnTodo,
              name: 'Spare',
              label: '',
            );
            await expectLater(
              remote.confirmAuthenticator(
                session,
                person: annaOnTodo,
                authenticator: spare.authenticator,
                code: codeOf(spare),
              ),
              refused(PasswordRefusal.wrongExistingCode),
            );
            now = now.add(totpPeriod);
            expect(
              await remote.confirmAuthenticator(
                session,
                person: annaOnTodo,
                authenticator: spare.authenticator,
                code: codeOf(spare),
                existingCode: codeOf(enrolment),
              ),
              isEmpty,
            );
            now = now.add(totpPeriod);
            await remote.removeAuthenticator(
              session,
              person: annaOnTodo,
              authenticator: spare.authenticator,
              code: codeOf(enrolment),
            );
            final ways = await remote.signInWaysOf(session, annaOnTodo);
            expect(ways.password && ways.authenticator, isTrue);

            now = now.add(totpPeriod);
            final challenge = await remote.beginPasswordSignIn(
              session,
              address: 'anna@example.org',
              network: '203.0.113.7',
            );
            final answer = device.answer(challenge);
            final proof = await remote.completePasswordSignIn(
              session,
              challenge: challenge.challenge,
              clientValue: answer.clientValue,
              clientProof: answer.clientProof,
              totpCode: codeOf(enrolment, at: now),
              host: testHost,
            );
            expect(proof.account, annaOnTodo);
            expect(answer.verifiesServer(proof.serverProof), isTrue);
            expect(proof.passwordKeys.toJson(), device.passwordKeys.toJson());
            final again = await remote.beginPasswordSignIn(
              session,
              address: 'anna@example.org',
              network: '203.0.113.7',
            );
            final againAnswer = device.answer(again);
            await expectLater(
              remote.completePasswordSignIn(
                session,
                challenge: again.challenge,
                clientValue: againAnswer.clientValue,
                clientProof: againAnswer.clientProof,
                totpCode: codeOf(enrolment, at: now),
                host: testHost,
              ),
              refused(PasswordRefusal.wrongCredentials),
            );

            now = now.add(totpPeriod);
            expect(
              await remote.newRecoveryCodes(
                session,
                person: annaOnTodo,
                code: codeOf(enrolment, at: now),
              ),
              hasLength(recoveryCodeCount),
            );

            final keyChallenge = await remote.beginKeyProof(
              session,
              address: 'anna@example.org',
              network: '203.0.113.7',
            );
            expect(
              keyChallenge.recoveryKeys.toJson(),
              device.recoveryKeys.toJson(),
            );
            now = now.add(totpPeriod);
            final newPassword = device.newPassword();
            expect(
              await remote.resetPasswordWithPhrase(
                session,
                challenge: keyChallenge.challenge,
                signature: await device.sign(
                  keyChallenge,
                  password: newPassword,
                ),
                password: newPassword,
                totpCode: codeOf(enrolment, at: now),
                host: testHost,
              ),
              (account: annaOnTodo, endedBefore: now),
            );
            // Every member is told to end the account's sessions too.
            expect(members.sessionsTold.single, (_todo, annaOnTodo, now, null));

            final forReset = await remote.beginPasswordSignIn(
              session,
              address: 'anna@example.org',
              network: '203.0.113.7',
            );
            final resetAnswer = device.answer(forReset);
            final resetRequest = await remote.sendSignInCode(
              session,
              address: 'anna@example.org',
              language: 'en',
              network: '203.0.113.7',
            );
            final pending = await remote.resetAuthenticator(
              session,
              challenge: forReset.challenge,
              clientValue: resetAnswer.clientValue,
              clientProof: resetAnswer.clientProof,
              address: 'anna@example.org',
              language: 'en',
              request: resetRequest,
              code: mailbox.codeFor('anna@example.org'),
              host: testHost,
            );
            expect(pending.takesEffectAt, now.add(resetDelay));

            final startRequest = await remote.sendSignInCode(
              session,
              address: 'anna@example.org',
              language: 'en',
              network: '203.0.113.7',
            );
            await remote.startAccountReset(
              session,
              address: 'anna@example.org',
              language: 'en',
              request: startRequest,
              code: mailbox.codeFor('anna@example.org'),
            );
            now = now.add(resetDelay);
            final fresh = await PasswordDevice.make(seed: 99);
            final completeRequest = await remote.sendSignInCode(
              session,
              address: 'anna@example.org',
              language: 'en',
              network: '203.0.113.7',
            );
            expect(
              await remote.completeAccountReset(
                session,
                address: 'anna@example.org',
                request: completeRequest,
                code: mailbox.codeFor('anna@example.org'),
                setup: fresh.setup(),
              ),
              (account: annaOnTodo, endedBefore: now),
            );
          });
        });
      });

      group('changes while signed in (ADR 0017)', () {
        late DateTime now;
        Future<T> atNow<T>(Future<T> Function() body) =>
            withClock(Clock(() => now), body);

        setUp(() {
          usePasswordKeys(pod, testPasswordKeys);
          now = DateTime.utc(2026, 10, 20, 12);
        });

        test(
          "cross for a member's device: the password, keeping the "
          "member's session, the phrase's wrapping, and a reset's date",
          () async {
            final device = await PasswordDevice.make();
            await atNow(() async {
              final annaOnTodo = const Uuid().v7obj();
              final annasPhone = const Uuid().v7obj();
              final request = await remote.sendSignInCode(
                session,
                address: 'anna@example.org',
                language: 'en',
                network: '203.0.113.7',
              );
              await remote.setPassword(
                session,
                person: annaOnTodo,
                setup: device.setup(),
                request: request,
                code: mailbox.codeFor('anna@example.org'),
              );
              final enrolment = await remote.enrolAuthenticator(
                session,
                person: annaOnTodo,
                name: 'Phone',
                label: 'anna@example.org',
              );
              await remote.confirmAuthenticator(
                session,
                person: annaOnTodo,
                authenticator: enrolment.authenticator,
                code: codeOf(enrolment),
              );
              now = now.add(totpPeriod);

              final challenge = await remote.beginPasswordChange(
                session,
                person: annaOnTodo,
              );
              final answer = device.answer(challenge);
              await remote.changePassword(
                session,
                person: annaOnTodo,
                challenge: challenge.challenge,
                clientValue: answer.clientValue,
                clientProof: answer.clientProof,
                totpCode: codeOf(enrolment),
                password: device.newPassword(),
                keepSession: annasPhone,
                host: testHost,
              );
              expect(members.sessionsTold.single, (
                _todo,
                annaOnTodo,
                now,
                annasPhone,
              ));

              now = now.add(totpPeriod);
              final fresh = WrappedKeys(
                nonce: ByteData(24),
                cipherText: ByteData(wrappedKeysLength),
              );
              Future<void> newPhrase() async {
                final challenge = await remote.beginPasswordChange(
                  session,
                  person: annaOnTodo,
                );
                final answer = device.answer(challenge);
                await remote.setRecoveryKeys(
                  session,
                  person: annaOnTodo,
                  challenge: challenge.challenge,
                  clientValue: answer.clientValue,
                  clientProof: answer.clientProof,
                  totpCode: codeOf(enrolment),
                  recoveryKeys: fresh,
                  recoveryProofKey: ByteData.sublistView(
                    device.recoveryProofKey,
                  ),
                  host: testHost,
                );
              }

              await newPhrase();
              // The same step's code again.
              await expectLater(
                newPhrase(),
                refused(PasswordRefusal.wrongCredentials),
              );

              final start = await remote.sendSignInCode(
                session,
                address: 'anna@example.org',
                language: 'en',
                network: '203.0.113.7',
              );
              final pending = await remote.startAccountReset(
                session,
                address: 'anna@example.org',
                language: 'en',
                request: start,
                code: mailbox.codeFor('anna@example.org'),
              );
              final early = await remote.sendSignInCode(
                session,
                address: 'anna@example.org',
                language: 'en',
                network: '203.0.113.7',
              );
              await expectLater(
                remote.completeAccountReset(
                  session,
                  address: 'anna@example.org',
                  request: early,
                  code: mailbox.codeFor('anna@example.org'),
                  setup: device.setup(),
                ),
                throwsA(
                  isA<PasswordRefusedException>().having(
                    (error) => error.takesEffectAt,
                    'takesEffectAt',
                    pending.takesEffectAt,
                  ),
                ),
              );
            });
          },
        );
      });

      group('ways in without a working password (ADR 0017)', () {
        late DateTime now;
        Future<T> atNow<T>(Future<T> Function() body) =>
            withClock(Clock(() => now), body);

        setUp(() {
          usePasswordKeys(pod, testPasswordKeys);
          now = DateTime.utc(2026, 10, 20, 12);
        });

        test("cross for a member's device: signing up with a code, and a "
            'setup never finished signing in with the password and a code, '
            'with what the register refuses', () async {
          final device = await PasswordDevice.make();
          await atNow(() async {
            Future<UuidValue> code() => remote.sendSignInCode(
              session,
              address: 'carla@example.org',
              language: 'en',
              network: '203.0.113.7',
            );
            final carla = await remote.signUpWithCode(
              session,
              request: await code(),
              code: mailbox.codeFor('carla@example.org'),
              setup: device.setup(),
            );
            expect(
              (await AuthUser.db.findById(session, carla))!.scopeNames,
              contains(identified.name),
            );
            await expectLater(
              remote.signUpWithCode(
                session,
                request: await code(),
                code: mailbox.codeFor('carla@example.org'),
                setup: device.setup(),
              ),
              refused(PasswordRefusal.passwordExists),
            );

            final challenge = await remote.beginPasswordSignIn(
              session,
              address: 'carla@example.org',
              network: '203.0.113.7',
            );
            final answer = device.answer(challenge);
            final proof = await remote.completePasswordSignIn(
              session,
              challenge: challenge.challenge,
              clientValue: answer.clientValue,
              clientProof: answer.clientProof,
              request: await code(),
              code: mailbox.codeFor('carla@example.org'),
              host: testHost,
            );
            expect(proof.account, carla);
            expect(proof.needsAuthenticator, isTrue);
          });
        });
      });

      group('deleting an account', () {
        test('deletes it here and tells every member, keeping no notice '
            'once they confirmed', () async {
          await remote.deleteAccount(session, ben);

          expect(await AuthUser.db.findById(session, ben), isNull);
          expect(await EmailIdentity.db.count(session), 0);
          expect(await GitHubAccount.db.count(session), 0);
          expect(members.told, [(_todo, ben)]);
          expect(await AccountDeletionNotice.db.count(session), 0);
          expect(await remote.knownAccounts(session, {ben}), isEmpty);
        });

        test(
          'tells a member that does not answer again until it does',
          () async {
            members.answers = (member) => member != _todo;

            await remote.deleteAccount(session, ben);

            expect(await AuthUser.db.findById(session, ben), isNull);
            final kept = await AccountDeletionNotice.db.find(session);
            expect(kept.single.account, ben);
            expect(kept.single.member, '$_todo');
            expect(kept.single.attempts, 1);
            expect(kept.single.lastAttemptAt, isNotNull);

            expect(await deliverDeletionNotices(session), 0);
            expect(
              (await AccountDeletionNotice.db.find(session)).single.attempts,
              2,
            );

            members.answers = (_) => true;
            expect(await deliverDeletionNotices(session), 1);
            expect(await AccountDeletionNotice.db.count(session), 0);
            expect(members.told, [(_todo, ben), (_todo, ben), (_todo, ben)]);
          },
        );

        test('tells the members of an account this server no longer has, '
            'as one may still hold its data', () async {
          final gone = const Uuid().v7obj();

          await remote.deleteAccount(session, gone);

          expect(members.told, [(_todo, gone)]);
        });

        test('tells nobody of an anonymous person, a member never having '
            'had them', () async {
          final anna = await newAnonymousPerson(session);

          await remote.deleteAccount(session, anna);

          expect(await AuthUser.db.findById(session, anna), isNull);
          expect(members.told, isEmpty);
          expect(await AccountDeletionNotice.db.count(session), 0);
        });

        test(
          'drops the notices of a member the operator no longer names',
          () async {
            members.answers = (_) => false;
            useBase(
              sessionBuilder,
              accounts: HoldsRegister(members: [_todo, _train]),
            );
            await remote.deleteAccount(session, ben);
            expect(await AccountDeletionNotice.db.count(session), 2);

            useBase(sessionBuilder, accounts: HoldsRegister(members: [_train]));
            await deliverDeletionNotices(session);

            expect(
              (await AccountDeletionNotice.db.find(session)).single.member,
              '$_train',
            );
            useBase(sessionBuilder);
            await deliverDeletionNotices(session);
            expect(await AccountDeletionNotice.db.count(session), 0);
          },
        );
      });
    },
  );

  group('A member asking the register', () {
    late List<http.Request> requests;

    /// A register answering every request with [status] and [body].
    RemoteRegister answering(int status, String body) {
      requests = [];
      return RemoteRegister(
        Uri.parse('http://learn.test:8082'),
        secret: _secret,
        client: () => MockClient((request) async {
          requests.add(request);
          return http.Response(body, status);
        }),
      );
    }

    test(
      'posts JSON to the operation with the secret as its bearer token',
      () async {
        final account = const Uuid().v7obj();
        final register = answering(200, '{"account": "${account.uuid}"}');

        expect(await register.accountWithGitHub(_noSession, '1001'), account);
        final request = requests.single;
        expect(request.method, 'POST');
        expect(
          '${request.url}',
          'http://learn.test:8082/halkyon-base/register/account-with-github',
        );
        expect(request.headers['authorization'], 'Bearer $_secret');
        expect(jsonDecode(request.body), {'gitHubUserId': '1001'});
      },
    );

    test(
      'fails as unavailable for an answer it cannot take, never guessing',
      () async {
        for (final (status, body) in [
          (500, '{}'),
          (401, '{"error": "secret"}'),
          (200, 'not JSON'),
          (200, '[]'),
          (409, '{"refusal": {"kind": "email", "reason": "unheardOf"}}'),
          (409, '{"refusal": "no"}'),
          (404, '{"error": "not here"}'),
        ]) {
          await expectLater(
            answering(status, body).accountWithGitHub(_noSession, '1001'),
            throwsA(isA<RegisterUnavailableException>()),
            reason: '$status $body',
          );
        }
        await expectLater(
          RemoteRegister(
            Uri.parse('http://learn.test:8082'),
            secret: _secret,
            client: () => MockClient(
              (_) async => throw http.ClientException('Connection refused'),
            ),
          ).accountWithGitHub(_noSession, '1001'),
          throwsA(isA<RegisterUnavailableException>()),
        );
      },
    );
  });

  group('The register telling a member', () {
    test("posts the account to the member's path with the secret, and "
        'counts only a 200 as confirmed', () async {
      final account = const Uuid().v7obj();
      final requests = <http.Request>[];
      var status = 200;
      final notifier = HttpMemberNotifier(
        secret: _secret,
        client: MockClient((request) async {
          requests.add(request);
          return http.Response('{}', status);
        }),
      );

      expect(await notifier.accountGone(_todo, account), isTrue);
      final request = requests.single;
      expect(request.method, 'POST');
      expect('${request.url}', 'http://todo.test:8082$accountGonePath');
      expect(request.headers['authorization'], 'Bearer $_secret');
      expect(jsonDecode(request.body), {'account': account.uuid});

      status = 401;
      expect(await notifier.accountGone(_todo, account), isFalse);
    });

    test('counts a failed request as not confirmed, and sends nothing '
        'without a secret', () async {
      final account = const Uuid().v7obj();
      var sent = 0;

      expect(
        await HttpMemberNotifier(
          secret: _secret,
          client: MockClient((_) {
            sent++;
            return Future.error(http.ClientException('Connection refused'));
          }),
        ).accountGone(_todo, account),
        isFalse,
      );
      expect(
        await HttpMemberNotifier(
          secret: null,
          client: MockClient((_) async {
            sent++;
            return http.Response('{}', 200);
          }),
        ).accountGone(_todo, account),
        isFalse,
      );
      expect(sent, 1);
    });
  });
}

/// No session: [RemoteRegister] only passes it on.
final Session _noSession = _NoSession();

final class _NoSession implements Session {
  @override
  Object? noSuchMethod(Invocation invocation) =>
      throw UnsupportedError('no session in this test');
}

Future<void> _deleteAll(Session session) async {
  await SignInChallenge.db.deleteWhere(
    session,
    where: (t) => t.id.notEquals(null),
  );
  await AccountReset.db.deleteWhere(session, where: (t) => t.id > 0);
  await RecoveryCode.db.deleteWhere(session, where: (t) => t.id > 0);
  await TotpAuthenticator.db.deleteWhere(
    session,
    where: (t) => t.id.notEquals(null),
  );
  await AccountPassword.db.deleteWhere(session, where: (t) => t.id > 0);
  await AccountDeletionNotice.db.deleteWhere(session, where: (t) => t.id > 0);
  await PublicProfile.db.deleteWhere(session, where: (t) => t.id > 0);
  await RateLimitedRequestAttempt.db.deleteWhere(
    session,
    where: (t) => t.id.notEquals(null),
  );
  await EmailCodeRequest.db.deleteWhere(
    session,
    where: (t) => t.id.notEquals(null),
  );
  await SecretChallenge.db.deleteWhere(
    session,
    where: (t) => t.id.notEquals(null),
  );
  await EmailIdentity.db.deleteWhere(
    session,
    where: (t) => t.id.notEquals(null),
  );
  await AuthUser.db.deleteWhere(session, where: (t) => t.id.notEquals(null));
}