fix(flutter): Query.didUpdateWidget and policy overrides

Author: nivekz

packages/graphql_flutter/lib/src/widgets/query.dart

@@ -72,7 +72,13 @@ class QueryState extends State<Query> {
   void didUpdateWidget(Query oldWidget) {
     super.didUpdateWidget(oldWidget);
 
-    if (!observableQuery.options.areEqualTo(_options)) {
+    final GraphQLClient client = GraphQLProvider.of(context).value;
+
+    final optionsWithOverrides = _options;
+    optionsWithOverrides.policies = client.defaultPolicies.watchQuery
+      .withOverrides(optionsWithOverrides.policies);
+
+    if (!observableQuery.options.areEqualTo(optionsWithOverrides)) {
       _initQuery();
     }
   }

packages/graphql_flutter/test/widgets/query_test.dart

@@ -0,0 +1,227 @@
+import 'package:flutter/material.dart';
+import 'package:flutter_test/flutter_test.dart';
+import 'package:graphql_flutter/graphql_flutter.dart';
+import 'package:graphql_flutter/src/widgets/query.dart';
+import 'package:http/http.dart';
+import 'package:mockito/mockito.dart';
+
+class MockHttpClient extends Mock implements Client {}
+
+final query = gql("""
+  query Foo {
+    foo
+  }
+""");
+
+class Page extends StatefulWidget {
+  final Map<String, dynamic> variables;
+  final FetchPolicy fetchPolicy;
+  final ErrorPolicy errorPolicy;
+
+  Page({
+    Key key,
+    this.variables,
+    this.fetchPolicy,
+    this.errorPolicy,
+  }): super(key: key);
+
+  @override
+  State<StatefulWidget> createState() => PageState();
+}
+
+class PageState extends State<Page> {
+  Map<String, dynamic> variables;
+  FetchPolicy fetchPolicy;
+  ErrorPolicy errorPolicy;
+
+  @override
+  void initState() {
+    super.initState();
+    variables = widget.variables;
+    fetchPolicy = widget.fetchPolicy;
+    errorPolicy = widget.errorPolicy;
+  }
+
+  setVariables(Map<String, dynamic> newVariables) {
+    setState(() {
+      variables = newVariables;
+    });
+  }
+
+  setFetchPolicy(FetchPolicy newFetchPolicy) {
+    setState(() {
+      fetchPolicy = newFetchPolicy;
+    });
+  }
+
+  setErrorPolicy(ErrorPolicy newErrorPolicy) {
+    setState(() {
+      errorPolicy = newErrorPolicy;
+    });
+  }
+
+  @override
+  Widget build(BuildContext context) {
+    return Query(
+      options: QueryOptions(
+        documentNode: query,
+        variables: variables,
+        fetchPolicy: fetchPolicy,
+        errorPolicy: errorPolicy,
+      ),
+      builder: (QueryResult result, {
+        Refetch refetch,
+        FetchMore fetchMore
+      }) => Container(),
+    );
+  }
+}
+
+void main() {
+  group('Query', () {
+    MockHttpClient mockHttpClient;
+    HttpLink httpLink;
+    ValueNotifier<GraphQLClient> client;
+
+    setUp(() async {
+      mockHttpClient = MockHttpClient();
+      httpLink = HttpLink(
+        uri: 'https://unused/graphql',
+        httpClient: mockHttpClient,
+      );
+      client = ValueNotifier(
+        GraphQLClient(
+          cache: InMemoryCache(storagePrefix: 'test'),
+          link: httpLink,
+        ),
+      );
+    });
+
+    testWidgets('does not issue network request on same options',
+        (WidgetTester tester) async {
+      final page = Page(
+        variables: {
+          'foo': 1,
+        },
+        fetchPolicy: FetchPolicy.networkOnly,
+        errorPolicy: ErrorPolicy.ignore,
+      );
+
+      await tester.pumpWidget(GraphQLProvider(
+        client: client,
+        child: page,
+      ));
+
+      verify(mockHttpClient.send(any)).called(1);
+
+      tester.state<PageState>(find.byWidget(page))
+        ..setVariables({'foo': 1})
+        ..setFetchPolicy(FetchPolicy.networkOnly)
+        ..setErrorPolicy(ErrorPolicy.ignore);
+      await tester.pump();
+      verifyNoMoreInteractions(mockHttpClient);
+    });
+
+    testWidgets('does not issue network request when policies stays null',
+        (WidgetTester tester) async {
+      final page = Page(
+        variables: {
+          'foo': 1,
+        },
+      );
+
+      await tester.pumpWidget(GraphQLProvider(
+        client: client,
+        child: page,
+      ));
+
+      verify(mockHttpClient.send(any)).called(1);
+
+      tester.state<PageState>(find.byWidget(page))
+        ..setFetchPolicy(null)
+        ..setErrorPolicy(null);
+      await tester.pump();
+      verifyNoMoreInteractions(mockHttpClient);
+    });
+
+    testWidgets('issues a new network request when variables change',
+        (WidgetTester tester) async {
+      final page = Page(
+        variables: {
+          'foo': 1,
+        },
+      );
+
+      await tester.pumpWidget(GraphQLProvider(
+        client: client,
+        child: page,
+      ));
+
+      verify(mockHttpClient.send(any)).called(1);
+
+      tester.state<PageState>(find.byWidget(page))
+        .setVariables({'foo': 2});
+      await tester.pump();
+      verify(mockHttpClient.send(any)).called(1);
+    });
+
+    testWidgets('issues a new network request when fetch policy changes',
+        (WidgetTester tester) async {
+      final page = Page(
+        fetchPolicy: FetchPolicy.networkOnly,
+      );
+
+      await tester.pumpWidget(GraphQLProvider(
+        client: client,
+        child: page,
+      ));
+
+      verify(mockHttpClient.send(any)).called(1);
+
+      tester.state<PageState>(find.byWidget(page))
+        .setFetchPolicy(FetchPolicy.cacheFirst);
+      await tester.pump();
+      verify(mockHttpClient.send(any)).called(1);
+    });
+
+    testWidgets('issues a new network request when error policy changes',
+        (WidgetTester tester) async {
+      final page = Page(
+        errorPolicy: ErrorPolicy.all,
+      );
+
+      await tester.pumpWidget(GraphQLProvider(
+        client: client,
+        child: page,
+      ));
+
+      verify(mockHttpClient.send(any)).called(1);
+
+      tester.state<PageState>(find.byWidget(page))
+        .setErrorPolicy(ErrorPolicy.none);
+      await tester.pump();
+      verify(mockHttpClient.send(any)).called(1);
+    });
+
+    testWidgets('does not issues new network request when policies are effectively unchanged',
+        (WidgetTester tester) async {
+      final page = Page(
+        fetchPolicy: FetchPolicy.cacheAndNetwork,
+        errorPolicy: null,
+      );
+
+      await tester.pumpWidget(GraphQLProvider(
+        client: client,
+        child: page,
+      ));
+
+      verify(mockHttpClient.send(any)).called(1);
+
+      tester.state<PageState>(find.byWidget(page))
+        ..setFetchPolicy(null)
+        ..setErrorPolicy(ErrorPolicy.none);
+      await tester.pump();
+      verifyNoMoreInteractions(mockHttpClient);
+    });
+  });
+}