store: Throw exception when account already logged in

When account is already logged in, throw AccountAlreadyExists to allow
caller to catch and handle exception.

Author: chrisirhc

lib/model/database.dart

@@ -2,8 +2,10 @@ import 'dart:io';
 
 import 'package:drift/drift.dart';
 import 'package:drift/native.dart';
+import 'package:drift/remote.dart';
 import 'package:path/path.dart' as path;
 import 'package:path_provider/path_provider.dart';
+import 'package:sqlite3/common.dart';
 
 part 'database.g.dart';
 
@@ -103,7 +105,21 @@ class AppDatabase extends _$AppDatabase {
     );
   }
 
-  Future<int> createAccount(AccountsCompanion values) {
-    return into(accounts).insert(values);
+  Future<int> createAccount(AccountsCompanion values) async {
+    try {
+      return await into(accounts).insert(values);
+    } catch (e) {
+      // Unwrap cause if it's a remote Drift call. On the app, it's running
+      // via a remote, but on local tests, it's running natively so
+      // unwrapping is not required.
+      final cause = (e is DriftRemoteException) ? e.remoteCause : e;
+      if (cause case SqliteException(
+              extendedResultCode: SqlExtendedError.SQLITE_CONSTRAINT_UNIQUE)) {
+        throw AccountAlreadyExistsException();
+      }
+      rethrow;
+    }
   }
 }
+
+class AccountAlreadyExistsException implements Exception {}

lib/model/store.dart

@@ -25,7 +25,7 @@ import 'stream.dart';
 import 'unreads.dart';
 
 export 'package:drift/drift.dart' show Value;
-export 'database.dart' show Account, AccountsCompanion;
+export 'database.dart' show Account, AccountsCompanion, AccountAlreadyExistsException;
 
 /// Store for all the user's data.
 ///

test/model/database_test.dart

@@ -41,6 +41,54 @@ void main() {
         'acked_push_token': null,
       });
     });
+
+    test('create account with same realm and userId ', () async {
+      final accountData = AccountsCompanion.insert(
+        realmUrl: Uri.parse('https://chat.example/'),
+        userId: 1,
+        email: '[email protected]',
+        apiKey: '1234',
+        zulipVersion: '6.0',
+        zulipMergeBase: const Value('6.0'),
+        zulipFeatureLevel: 42,
+      );
+      final accountDataWithSameUserId = AccountsCompanion.insert(
+        realmUrl: Uri.parse('https://chat.example/'),
+        userId: 1,
+        email: '[email protected]',
+        apiKey: '12345',
+        zulipVersion: '6.0',
+        zulipMergeBase: const Value('6.0'),
+        zulipFeatureLevel: 42,
+      );
+      await database.createAccount(accountData);
+      await check(database.createAccount(accountDataWithSameUserId))
+        .throws<AccountAlreadyExistsException>();
+    });
+
+    test('create account with same realm and email', () async {
+      final accountData = AccountsCompanion.insert(
+        realmUrl: Uri.parse('https://chat.example/'),
+        userId: 1,
+        email: '[email protected]',
+        apiKey: '1234',
+        zulipVersion: '6.0',
+        zulipMergeBase: const Value('6.0'),
+        zulipFeatureLevel: 42,
+      );
+      final accountDataWithSameEmail = AccountsCompanion.insert(
+        realmUrl: Uri.parse('https://chat.example/'),
+        userId: 2,
+        email: '[email protected]',
+        apiKey: '12345',
+        zulipVersion: '6.0',
+        zulipMergeBase: const Value('6.0'),
+        zulipFeatureLevel: 42,
+      );
+      await database.createAccount(accountData);
+      await check(database.createAccount(accountDataWithSameEmail))
+        .throws<AccountAlreadyExistsException>();
+    });
   });
 
   group('migrations', () {

test/model/test_store.dart

@@ -76,6 +76,16 @@ class TestGlobalStore extends GlobalStore {
 
   @override
   Future<Account> doInsertAccount(AccountsCompanion data) async {
+    // Check for duplication is typically handled by the database but since
+    // we're not using a real database, this needs to be handled here.
+    // See [AppDatabase.createAccount].
+    if (accounts.any((account) =>
+          data.realmUrl.value == account.realmUrl
+          && (data.userId.value == account.userId
+              || data.email.value == account.email))) {
+      throw AccountAlreadyExistsException();
+    }
+
     final accountId = data.id.present ? data.id.value : _nextAccountId++;
     return Account(
       id: accountId,