feat: home grid

mobile-v2/lib/utils/extensions/drift.extension.dart

@@ -0,0 +1,30 @@
+import 'package:drift/drift.dart';
+
+extension ExpandQuery<T> on Selectable<T> {
+  /// Expands this selectable by the [expand] function.
+  ///
+  /// Each entry emitted by this [Selectable] will be transformed by the
+  /// [expander] and then emitted to the selectable returned.
+  Selectable<N> expand<N>(Iterable<N> Function(T) expander) {
+    return _ExpandedSelectable<T, N>(this, expander);
+  }
+}
+
+class _ExpandedSelectable<S, T> extends Selectable<T> {
+  final Selectable<S> _source;
+  final Iterable<T> Function(S) expander;
+
+  _ExpandedSelectable(this._source, this.expander);
+
+  @override
+  Future<List<T>> get() {
+    return _source.get().then(_mapResults);
+  }
+
+  @override
+  Stream<List<T>> watch() {
+    return _source.watch().map(_mapResults);
+  }
+
+  List<T> _mapResults(List<S> results) => results.expand<T>(expander).toList();
+}