db: Create GlobalSettings row as part of schema setup

This is a little more complicated in the code overall; but it
simplifies the logic that runs each time the app starts up.

Author: gnprice

lib/model/database.dart

@@ -9,11 +9,13 @@ import 'settings.dart';
 
 part 'database.g.dart';
 
-/// The table of the user's chosen settings independent of account, on this
-/// client.
+/// The table of one [GlobalSettingsData] record, the user's chosen settings
+/// on this client that are independent of account.
 ///
 /// These apply across all the user's accounts on this client (i.e. on this
 /// install of the app on this device).
+///
+/// This table should always have exactly one row (it's created by a migration).
 @DataClassName('GlobalSettingsData')
 class GlobalSettings extends Table {
   Column<String> get themeSetting => textEnum<ThemeSetting>()
@@ -78,6 +80,8 @@ VersionedSchema _getSchema({
       return Schema3(database: database);
     case 4:
       return Schema4(database: database);
+    case 5:
+      return Schema5(database: database);
     default:
       throw Exception('unknown schema version: $schemaVersion');
   }
@@ -98,7 +102,7 @@ class AppDatabase extends _$AppDatabase {
   //  * Write a migration in `_migrationSteps` below.
   //  * Write tests.
   @override
-  int get schemaVersion => 4; // See note.
+  int get schemaVersion => 5; // See note.
 
   static Future<void> _dropAndCreateAll(Migrator m, {
     required int schemaVersion,
@@ -136,13 +140,31 @@ class AppDatabase extends _$AppDatabase {
       await m.addColumn(
         schema.globalSettings, schema.globalSettings.browserPreference);
     },
+    from4To5: (m, schema) async {
+      // Corresponds to the `into(globalSettings).insert` in `onCreate`.
+      // This migration ensures there is a row in GlobalSettings.
+      // (If the app already ran at schema 3 or 4, there will be;
+      // if not, there won't be before this point.)
+      await m.database.transaction(() async {
+        final rows = await m.database.select(schema.globalSettings).get();
+        if (rows.isEmpty) {
+          await m.database.into(schema.globalSettings).insert(
+            // No field values; just use the defaults for both fields.
+            // (This is like `GlobalSettingsCompanion.insert()`, but
+            // without dependence on the current schema.)
+            RawValuesInsertable({}));
+        }
+      });
+    },
   );
 
   @override
   MigrationStrategy get migration {
     return MigrationStrategy(
       onCreate: (Migrator m) async {
         await m.createAll();
+        // Corresponds to `from4to5` above.
+        await into(globalSettings).insert(GlobalSettingsCompanion());
       },
       onUpgrade: (Migrator m, int from, int to) async {
         if (from > to) {
@@ -159,23 +181,10 @@ class AppDatabase extends _$AppDatabase {
       });
   }
 
+  // TODO rename ensureGlobalSettings to reflect its reduced role
   Future<GlobalSettingsData> ensureGlobalSettings() async {
-    final settings = await select(globalSettings).get();
-    // TODO(db): Enforce the singleton constraint more robustly.
-    if (settings.isNotEmpty) {
-      if (settings.length > 1) {
-        assert(debugLog('Expected one globalSettings, got multiple: $settings'));
-      }
-      return settings.first;
-    }
-
-    final rowsAffected = await into(globalSettings).insert(GlobalSettingsCompanion.insert());
-    assert(rowsAffected == 1);
-    final result = await select(globalSettings).get();
-    if (result.length > 1) {
-      assert(debugLog('Expected one globalSettings, got multiple: $result'));
-    }
-    return result.first;
+    // The migrations ensure there is a row.
+    return await (select(globalSettings)..limit(1)).getSingle();
   }
 
   Future<int> createAccount(AccountsCompanion values) async {

lib/model/schema_versions.g.dart

@@ -241,10 +241,56 @@ i1.GeneratedColumn<String> _column_10(String aliasedName) =>
       true,
       type: i1.DriftSqlType.string,
     );
+
+final class Schema5 extends i0.VersionedSchema {
+  Schema5({required super.database}) : super(version: 5);
+  @override
+  late final List<i1.DatabaseSchemaEntity> entities = [
+    globalSettings,
+    accounts,
+  ];
+  late final Shape2 globalSettings = Shape2(
+    source: i0.VersionedTable(
+      entityName: 'global_settings',
+      withoutRowId: false,
+      isStrict: false,
+      tableConstraints: [],
+      columns: [_column_9, _column_10],
+      attachedDatabase: database,
+    ),
+    alias: null,
+  );
+  late final Shape0 accounts = Shape0(
+    source: i0.VersionedTable(
+      entityName: 'accounts',
+      withoutRowId: false,
+      isStrict: false,
+      tableConstraints: [
+        'UNIQUE(realm_url, user_id)',
+        'UNIQUE(realm_url, email)',
+      ],
+      columns: [
+        _column_0,
+        _column_1,
+        _column_2,
+        _column_3,
+        _column_4,
+        _column_5,
+        _column_6,
+        _column_7,
+        _column_8,
+      ],
+      attachedDatabase: database,
+    ),
+    alias: null,
+  );
+}
+
 i0.MigrationStepWithVersion migrationSteps({
   required Future<void> Function(i1.Migrator m, Schema2 schema) from1To2,
   required Future<void> Function(i1.Migrator m, Schema3 schema) from2To3,
   required Future<void> Function(i1.Migrator m, Schema4 schema) from3To4,
+  required Future<void> Function(i1.Migrator m, Schema5 schema) from4To5,
 }) {
   return (currentVersion, database) async {
     switch (currentVersion) {
@@ -263,6 +309,11 @@ i0.MigrationStepWithVersion migrationSteps({
         final migrator = i1.Migrator(database, schema);
         await from3To4(migrator, schema);
         return 4;
+      case 4:
+        final schema = Schema5(database: database);
+        final migrator = i1.Migrator(database, schema);
+        await from4To5(migrator, schema);
+        return 5;
       default:
         throw ArgumentError.value('Unknown migration from $currentVersion');
     }
@@ -273,10 +324,12 @@ i1.OnUpgrade stepByStep({
   required Future<void> Function(i1.Migrator m, Schema2 schema) from1To2,
   required Future<void> Function(i1.Migrator m, Schema3 schema) from2To3,
   required Future<void> Function(i1.Migrator m, Schema4 schema) from3To4,
+  required Future<void> Function(i1.Migrator m, Schema5 schema) from4To5,
 }) => i0.VersionedSchema.stepByStepHelper(
   step: migrationSteps(
     from1To2: from1To2,
     from2To3: from2To3,
     from3To4: from3To4,
+    from4To5: from4To5,
   ),
 );

lib/model/store.dart

@@ -65,8 +65,6 @@ abstract class GlobalStore extends ChangeNotifier {
   GlobalSettingsData _globalSettings;
 
   /// Update the global settings in the store.
-  ///
-  /// The global settings must already exist in the store.
   Future<void> updateGlobalSettings(GlobalSettingsCompanion data) async {
     await doUpdateGlobalSettings(data);
     _globalSettings = _globalSettings.copyWithCompanion(data);

test/model/database_test.dart

@@ -11,6 +11,7 @@ import 'schemas/schema_v1.dart' as v1;
 import 'schemas/schema_v2.dart' as v2;
 import 'schemas/schema_v3.dart' as v3;
 import 'schemas/schema_v4.dart' as v4;
+import 'schemas/schema_v5.dart' as v5;
 import 'store_checks.dart';
 
 void main() {
@@ -29,8 +30,6 @@ void main() {
     });
 
     test('ensure single GlobalSettings row', () async {
-      check(await database.select(database.globalSettings).get()).isEmpty();
-
       final globalSettings = await database.ensureGlobalSettings();
       check(await database.select(database.globalSettings).get())
         .single.equals(globalSettings);
@@ -44,12 +43,9 @@ void main() {
     test('does not crash if multiple global settings rows', () async {
       await database.into(database.globalSettings)
         .insert(const GlobalSettingsCompanion(themeSetting: Value(ThemeSetting.dark)));
-      await database.into(database.globalSettings)
-        .insert(const GlobalSettingsCompanion(themeSetting: Value(ThemeSetting.light)));
 
       check(await database.select(database.globalSettings).get()).length.equals(2);
-      check(await database.ensureGlobalSettings())
-        .themeSetting.equals(ThemeSetting.dark);
+      check(await database.ensureGlobalSettings()).themeSetting.isNull();
     });
 
     test('GlobalSettings updates work', () async {
@@ -236,6 +232,42 @@ void main() {
       check(globalSettings.browserPreference).isNull();
       await after.close();
     });
+
+    test('upgrade to v5: with existing GlobalSettings row, do nothing', () async {
+      final schema = await verifier.schemaAt(4);
+      final before = v4.DatabaseAtV4(schema.newConnection());
+      await before.into(before.globalSettings).insert(
+        v4.GlobalSettingsCompanion.insert(
+          themeSetting: Value(ThemeSetting.light.name)));
+      await before.close();
+
+      final db = AppDatabase(schema.newConnection());
+      await verifier.migrateAndValidate(db, 5);
+      await db.close();
+
+      final after = v5.DatabaseAtV5(schema.newConnection());
+      final globalSettings = await after.select(after.globalSettings).getSingle();
+      check(globalSettings.themeSetting).equals(ThemeSetting.light.name);
+      check(globalSettings.browserPreference).isNull();
+      await after.close();
+    });
+
+    test('upgrade to v5: with no existing GlobalSettings row, insert one', () async {
+      final schema = await verifier.schemaAt(4);
+      final before = v4.DatabaseAtV4(schema.newConnection());
+      check(await before.select(before.globalSettings).get()).isEmpty();
+      await before.close();
+
+      final db = AppDatabase(schema.newConnection());
+      await verifier.migrateAndValidate(db, 5);
+      await db.close();
+
+      final after = v5.DatabaseAtV5(schema.newConnection());
+      final globalSettings = await after.select(after.globalSettings).getSingle();
+      check(globalSettings.themeSetting).isNull();
+      check(globalSettings.browserPreference).isNull();
+      await after.close();
+    });
   });
 }
 

test/model/schemas/drift_schema_v5.json

@@ -0,0 +1 @@
+{"_meta":{"description":"This file contains a serialized version of schema entities for drift.","version":"1.2.0"},"options":{"store_date_time_values_as_text":false},"entities":[{"id":0,"references":[],"type":"table","data":{"name":"global_settings","was_declared_in_moor":false,"columns":[{"name":"theme_setting","getter_name":"themeSetting","moor_type":"string","nullable":true,"customConstraints":null,"default_dart":null,"default_client_dart":null,"dsl_features":[],"type_converter":{"dart_expr":"const EnumNameConverter<ThemeSetting>(ThemeSetting.values)","dart_type_name":"ThemeSetting"}},{"name":"browser_preference","getter_name":"browserPreference","moor_type":"string","nullable":true,"customConstraints":null,"default_dart":null,"default_client_dart":null,"dsl_features":[],"type_converter":{"dart_expr":"const EnumNameConverter<BrowserPreference>(BrowserPreference.values)","dart_type_name":"BrowserPreference"}}],"is_virtual":false,"without_rowid":false,"constraints":[]}},{"id":1,"references":[],"type":"table","data":{"name":"accounts","was_declared_in_moor":false,"columns":[{"name":"id","getter_name":"id","moor_type":"int","nullable":false,"customConstraints":null,"defaultConstraints":"PRIMARY KEY AUTOINCREMENT","dialectAwareDefaultConstraints":{"sqlite":"PRIMARY KEY AUTOINCREMENT"},"default_dart":null,"default_client_dart":null,"dsl_features":["auto-increment"]},{"name":"realm_url","getter_name":"realmUrl","moor_type":"string","nullable":false,"customConstraints":null,"default_dart":null,"default_client_dart":null,"dsl_features":[],"type_converter":{"dart_expr":"const UriConverter()","dart_type_name":"Uri"}},{"name":"user_id","getter_name":"userId","moor_type":"int","nullable":false,"customConstraints":null,"default_dart":null,"default_client_dart":null,"dsl_features":[]},{"name":"email","getter_name":"email","moor_type":"string","nullable":false,"customConstraints":null,"default_dart":null,"default_client_dart":null,"dsl_features":[]},{"name":"api_key","getter_name":"apiKey","moor_type":"string","nullable":false,"customConstraints":null,"default_dart":null,"default_client_dart":null,"dsl_features":[]},{"name":"zulip_version","getter_name":"zulipVersion","moor_type":"string","nullable":false,"customConstraints":null,"default_dart":null,"default_client_dart":null,"dsl_features":[]},{"name":"zulip_merge_base","getter_name":"zulipMergeBase","moor_type":"string","nullable":true,"customConstraints":null,"default_dart":null,"default_client_dart":null,"dsl_features":[]},{"name":"zulip_feature_level","getter_name":"zulipFeatureLevel","moor_type":"int","nullable":false,"customConstraints":null,"default_dart":null,"default_client_dart":null,"dsl_features":[]},{"name":"acked_push_token","getter_name":"ackedPushToken","moor_type":"string","nullable":true,"customConstraints":null,"default_dart":null,"default_client_dart":null,"dsl_features":[]}],"is_virtual":false,"without_rowid":false,"constraints":[],"unique_keys":[["realm_url","user_id"],["realm_url","email"]]}}]}

test/model/schemas/schema.dart

@@ -7,6 +7,7 @@ import 'schema_v1.dart' as v1;
 import 'schema_v2.dart' as v2;
 import 'schema_v3.dart' as v3;
 import 'schema_v4.dart' as v4;
+import 'schema_v5.dart' as v5;
 
 class GeneratedHelper implements SchemaInstantiationHelper {
   @override
@@ -20,10 +21,12 @@ class GeneratedHelper implements SchemaInstantiationHelper {
         return v3.DatabaseAtV3(db);
       case 4:
         return v4.DatabaseAtV4(db);
+      case 5:
+        return v5.DatabaseAtV5(db);
       default:
         throw MissingSchemaException(version, versions);
     }
   }
 
-  static const versions = const [1, 2, 3, 4];
+  static const versions = const [1, 2, 3, 4, 5];
 }