sling_gql_test 1.2.0

Test helpers for sling_gql: an in-memory GraphQL server that answers the client's own documents from plain Dart data, and pumpUntilSettled for widget tests.

example/sling_gql_test_example.dart

// A widget test with sling_gql_test: the server answers from plain maps,
// `pumpUntilSettled` waits for the round trip, `server.requests` is the log.
//
// In a real app the `Query` / `User` / `Mutation` classes at the bottom are
// generated by `sling_gql_gen`; they are written out here so the example runs
// on its own (`flutter test example/`).
//
//   type Query    { me: User!  user(id: ID!): User }
//   type User     { id: ID!  name: String!  age: Int }
//   type Mutation { rename(id: ID!, name: String!): User! }

import 'package:flutter/widgets.dart';
import 'package:flutter_test/flutter_test.dart';
import 'package:sling_gql/sling_gql.dart';
import 'package:sling_gql_test/sling_gql_test.dart';

void main() {
  testWidgets('shows the viewer, renames them', (tester) async {
    final ada = {'__typename': 'User', 'id': '1', 'name': 'Ada', 'age': 36};
    final server = MockGraphQLServer(
      query: {'me': ada, 'user': (args) => args['id'] == '1' ? ada : null},
      mutation: {'rename': (args) => ada..['name'] = args['name']},
    );
    final client = server.client(Query.root);

    await tester.pumpWidget(
      SlingScope<Query>(
        client: client,
        schema: slingSchema,
        child: const Directionality(
          textDirection: TextDirection.ltr,
          child: ProfileName(),
        ),
      ),
    );
    expect(find.text('loading'), findsOneWidget);

    await tester.pumpUntilSettled(client);
    expect(find.text('Ada'), findsOneWidget);
    expect(server.requests, hasLength(1));
    expect(server.lastRequest.selects('me.name'), isTrue);

    // The fields read in the body are the mutation's selection.
    final renamed = client.mutate(
      (m) => m.rename(id: '1', name: 'Grace')?.name,
    );
    await tester.pumpUntilSettled(client);
    expect(await renamed, 'Grace');
    expect(find.text('Grace'), findsOneWidget, reason: 'User:1 was notified');
    expect(server.lastRequest.type, 'mutation');
  });
}

class ProfileName extends StatelessWidget {
  const ProfileName({super.key});

  @override
  Widget build(BuildContext context) => QueryBuilder<Query>(
    builder: (context, query, state) => Text(query.me.name ?? 'loading'),
  );
}

// --- What sling_gql_gen would generate ---------------------------------------

class Query extends Accessor {
  Query(super.recorder, super.selection, super.path);
  Query.root(Recorder r) : super(r, r.root, const []);

  User get me => object('me', User.new, keyed: true)!;
  User? user({required String id}) =>
      object('user', User.new, args: {'id': Arg('ID!', id)}, lookup: 'User');
}

class User extends Accessor {
  User(super.recorder, super.selection, super.path);

  String? get id => scalar<String>('id');
  String? get name => scalar<String>('name');
  set name(String? v) => write('name', v);
  int? get age => scalar<int>('age');
}

class Mutation extends Accessor {
  Mutation(super.recorder, super.selection, super.path);
  Mutation.root(Recorder r) : super(r, r.root, const []);

  User? rename({required String id, required String name}) => object(
    'rename',
    User.new,
    args: {'id': Arg('ID!', id), 'name': Arg('String!', name)},
    keyed: true,
  );
}

extension SlingMutations on SlingClient<Query> {
  Future<T> mutate<T>(T Function(Mutation m) body) =>
      mutateWith(Mutation.root, body);
}

const slingSchema = SlingSchema<Query, Mutation>(
  query: Query.root,
  mutation: Mutation.root,
);