Improve compatibility check for core extension

packages/powersync_core/lib/powersync_core.dart

@@ -9,7 +9,6 @@ export 'src/database/powersync_database.dart';
 export 'src/exceptions.dart';
 export 'src/log.dart';
 export 'src/open_factory.dart';
-export 'src/powersync_database.dart';
 export 'src/schema.dart';
 export 'src/sync_status.dart';
 export 'src/uuid.dart';

packages/powersync_core/lib/src/database/core_version.dart

@@ -0,0 +1,65 @@
+import 'package:sqlite_async/sqlite3_common.dart';
+
+/// A parsed (major, minor, patch) version triple representing a version of the
+/// loaded core extension.
+extension type const PowerSyncCoreVersion((int, int, int) _tuple) {
+  int get major => _tuple.$1;
+  int get minor => _tuple.$2;
+  int get patch => _tuple.$3;
+
+  int compareTo(PowerSyncCoreVersion other) {
+    return switch (major.compareTo(other.major)) {
+      0 => switch (minor.compareTo(other.minor)) {
+          0 => patch.compareTo(other.patch),
+          var other => other,
+        },
+      var other => other,
+    };
+  }
+
+  bool operator <(PowerSyncCoreVersion other) => compareTo(other) < 0;
+  bool operator >=(PowerSyncCoreVersion other) => compareTo(other) >= 0;
+
+  String get versionString => '$major.$minor.$patch';
+
+  void checkSupported() {
+    const isWeb = bool.fromEnvironment('dart.library.js_interop');
+
+    if (this < minimum || this >= maximumExclusive) {
+      var message =
+          'Unsupported powersync extension version. This version of the '
+          'PowerSync SDK needs >=${minimum.versionString} '
+          '<${maximumExclusive.versionString}, '
+          'but detected version $versionString.';
+      if (isWeb) {
+        message +=
+            '\nTry downloading the updated assets: https://docs.powersync.com/client-sdk-references/flutter/flutter-web-support#assets';
+      }
+
+      throw SqliteException(1, message);
+    }
+  }
+
+  /// Parses the output of `powersync_rs_version()`, e.g. `0.3.9/5d64f366`, into
+  /// a [PowerSyncCoreVersion].
+  static PowerSyncCoreVersion parse(String version) {
+    try {
+      final [major, minor, patch] =
+          version.split(RegExp(r'[./]')).take(3).map(int.parse).toList();
+
+      return PowerSyncCoreVersion((major, minor, patch));
+    } catch (e) {
+      throw SqliteException(1,
+          'Unsupported powersync extension version. Need >=0.2.0 <1.0.0, got: $version. Details: $e');
+    }
+  }
+
+  /// The minimum version of the sqlite core extensions we support. We check
+  /// this version when opening databases to fail early and with an actionable
+  /// error message.
+  static const minimum = PowerSyncCoreVersion((0, 3, 11));
+
+  /// The first version of the core extensions that this version of the Dart
+  /// SDK doesn't support.
+  static const maximumExclusive = PowerSyncCoreVersion((1, 0, 0));
+}

packages/powersync_core/lib/src/database/powersync_db_mixin.dart

@@ -7,6 +7,7 @@ import 'package:powersync_core/sqlite_async.dart';
 import 'package:powersync_core/src/abort_controller.dart';
 import 'package:powersync_core/src/connector.dart';
 import 'package:powersync_core/src/crud.dart';
+import 'package:powersync_core/src/database/core_version.dart';
 import 'package:powersync_core/src/powersync_update_notification.dart';
 import 'package:powersync_core/src/schema.dart';
 import 'package:powersync_core/src/schema_logic.dart';
@@ -93,23 +94,7 @@ mixin PowerSyncDatabaseMixin implements SqliteConnection {
           1, 'The powersync extension is not loaded correctly. Details: $e');
     }
 
-    // Parse version
-    List<int> versionInts;
-    try {
-      versionInts =
-          version.split(RegExp(r'[./]')).take(3).map(int.parse).toList();
-    } catch (e) {
-      throw SqliteException(1,
-          'Unsupported powersync extension version. Need >=0.2.0 <1.0.0, got: $version. Details: $e');
-    }
-
-    // Validate >=0.2.0 <1.0.0
-    if (versionInts[0] != 0 ||
-        (versionInts[1] < 2) ||
-        (versionInts[1] == 2 && versionInts[2] < 0)) {
-      throw SqliteException(1,
-          'Unsupported powersync extension version. Need >=0.2.0 <1.0.0, got: $version');
-    }
+    PowerSyncCoreVersion.parse(version).checkSupported();
   }
 
   /// Wait for initialization to complete.

packages/powersync_core/test/database/core_version_test.dart

@@ -0,0 +1,39 @@
+import 'package:powersync_core/src/database/core_version.dart';
+import 'package:sqlite3/sqlite3.dart';
+import 'package:test/test.dart';
+
+void main() {
+  group('PowerSyncCoreVersion', () {
+    test('parse', () {
+      expect(PowerSyncCoreVersion.parse('0.3.9/5d64f366'), (0, 3, 9));
+    });
+
+    test('compare', () {
+      void expectLess(String a, String b) {
+        final parsedA = PowerSyncCoreVersion.parse(a);
+        final parsedB = PowerSyncCoreVersion.parse(b);
+
+        expect(parsedA.compareTo(parsedB), -1);
+        expect(parsedB.compareTo(parsedA), 1);
+
+        expect(parsedA.compareTo(parsedA), 0);
+        expect(parsedB.compareTo(parsedB), 0);
+      }
+
+      expectLess('0.1.0', '1.0.0');
+      expectLess('1.0.0', '1.2.0');
+      expectLess('0.3.9', '0.3.11');
+    });
+
+    test('checkSupported', () {
+      expect(PowerSyncCoreVersion.parse('0.3.10').checkSupported,
+          throwsA(isA<SqliteException>()));
+      expect(PowerSyncCoreVersion.parse('1.0.0').checkSupported,
+          throwsA(isA<SqliteException>()));
+
+      PowerSyncCoreVersion.minimum.checkSupported();
+      expect(PowerSyncCoreVersion.maximumExclusive.checkSupported,
+          throwsA(isA<SqliteException>()));
+    });
+  });
+}