From 22eed666e26012d8a66ba5e575b31a99bff299e6 Mon Sep 17 00:00:00 2001
From: Tobe O <thosakwe@gmail.com>
Date: Thu, 1 Nov 2018 20:29:47 -0400
Subject: [PATCH] Add types to resolvers

---
 angel_graphql/README.md              | 47 ++++++++++++++++++++++++++++
 angel_graphql/lib/src/resolvers.dart | 27 ++++++++--------
 2 files changed, 61 insertions(+), 13 deletions(-)

diff --git a/angel_graphql/README.md b/angel_graphql/README.md
index c660a952..7fac35c2 100644
--- a/angel_graphql/README.md
+++ b/angel_graphql/README.md
@@ -127,6 +127,53 @@ UI, ready-to-go!
 
 Now you're ready to build a GraphQL API!
 
+## Using Services
+What would Angel be without services? For those unfamiliar - in Angel,
+`Service` is a base class that implements CRUD functionality, and serves
+as the database interface within an Angel application. They are well-suited
+for NoSQL or other databases without a schema (they can be used with
+SQL, but that's not their primary focus).
+
+`package:angel_graphql` has functionality to resolve fields by interacting with
+services.
+
+Consider our previous example, and note the calls to
+`resolveViaServiceIndex` and `resolveViaServiceRead`:
+
+```dart
+var queryType = objectType(
+    'Query',
+    description: 'A simple API that manages your to-do list.',
+    fields: [
+      field(
+        'todos',
+        listOf(convertDartType(Todo).nonNullable()),
+        resolve: resolveViaServiceIndex(todoService),
+      ),
+      field(
+        'todo',
+        convertDartType(Todo),
+        resolve: resolveViaServiceRead(todoService),
+        inputs: [
+          new GraphQLFieldInput('id', graphQLId.nonNullable()),
+        ],
+      ),
+    ],
+  );
+```
+
+In all, there are:
+* `resolveViaServiceIndex`
+* `resolveViaServiceFindOne`
+* `resolveViaServiceRead`
+* `resolveViaServiceModify`
+* `resolveViaServiceUpdate`
+* `resolveViaServiceRemove`
+
+As one might imagine, using these convenience helpers makes
+it much quicker to implement CRUD functionality in a GraphQL
+API.
+
 ## Documentation
 The `convertDartType` function can automatically read the documentation
 from a type like the following:
diff --git a/angel_graphql/lib/src/resolvers.dart b/angel_graphql/lib/src/resolvers.dart
index 5919f543..28120817 100644
--- a/angel_graphql/lib/src/resolvers.dart
+++ b/angel_graphql/lib/src/resolvers.dart
@@ -12,14 +12,14 @@ Map<String, dynamic> _fetchRequestInfo(Map<String, dynamic> arguments) {
 ///
 /// The arguments passed to the resolver will be forwarded to the service, and the
 /// service will receive [Providers.graphql].
-GraphQLFieldResolver<Value, Serialized>
-    resolveViaServiceIndex<Value, Serialized>(Service service) {
+GraphQLFieldResolver<List<Value>, Serialized>
+    resolveViaServiceIndex<Value, Serialized>(Service<dynamic, Value> service) {
   return (_, arguments) async {
     var _requestInfo = _fetchRequestInfo(arguments);
     var params = {'query': arguments, 'provider': Providers.graphQL}
       ..addAll(_requestInfo);
 
-    return await service.index(params) as Value;
+    return await service.index(params);
   };
 }
 
@@ -28,12 +28,13 @@ GraphQLFieldResolver<Value, Serialized>
 /// The arguments passed to the resolver will be forwarded to the service, and the
 /// service will receive [Providers.graphql].
 GraphQLFieldResolver<Value, Serialized>
-    resolveViaServiceFindOne<Value, Serialized>(Service service) {
+    resolveViaServiceFindOne<Value, Serialized>(
+        Service<dynamic, Value> service) {
   return (_, arguments) async {
     var _requestInfo = _fetchRequestInfo(arguments);
     var params = {'query': arguments, 'provider': Providers.graphQL}
       ..addAll(_requestInfo);
-    return await service.findOne(params) as Value;
+    return await service.findOne(params);
   };
 }
 
@@ -45,14 +46,14 @@ GraphQLFieldResolver<Value, Serialized>
 /// The arguments passed to the resolver will be forwarded to the service, and the
 /// service will receive [Providers.graphql].
 GraphQLFieldResolver<Value, Serialized>
-    resolveViaServiceRead<Value, Serialized>(Service service,
+    resolveViaServiceRead<Value, Serialized>(Service<dynamic, Value> service,
         {String idField: 'id'}) {
   return (_, arguments) async {
     var _requestInfo = _fetchRequestInfo(arguments);
     var params = {'query': arguments, 'provider': Providers.graphQL}
       ..addAll(_requestInfo);
     var id = arguments.remove(idField);
-    return await service.read(id, params) as Value;
+    return await service.read(id, params);
   };
 }
 
@@ -65,14 +66,14 @@ GraphQLFieldResolver<Value, Serialized>
 /// The arguments passed to the resolver will be forwarded to the service, and the
 /// service will receive [Providers.graphql].
 GraphQLFieldResolver<Value, Serialized>
-    resolveViaServiceModify<Value, Serialized>(Service service,
+    resolveViaServiceModify<Value, Serialized>(Service<dynamic, Value> service,
         {String idField: 'id'}) {
   return (_, arguments) async {
     var _requestInfo = _fetchRequestInfo(arguments);
     var params = {'query': arguments, 'provider': Providers.graphQL}
       ..addAll(_requestInfo);
     var id = arguments.remove(idField);
-    return await service.modify(id, arguments['data'], params) as Value;
+    return await service.modify(id, arguments['data'] as Value, params);
   };
 }
 
@@ -88,14 +89,14 @@ GraphQLFieldResolver<Value, Serialized>
 /// Keep in mind that `update` **overwrites** existing contents.
 /// To avoid this, use [resolveViaServiceModify] instead.
 GraphQLFieldResolver<Value, Serialized>
-    resolveViaServiceUpdate<Value, Serialized>(Service service,
+    resolveViaServiceUpdate<Value, Serialized>(Service<dynamic, Value> service,
         {String idField: 'id'}) {
   return (_, arguments) async {
     var _requestInfo = _fetchRequestInfo(arguments);
     var params = {'query': arguments, 'provider': Providers.graphQL}
       ..addAll(_requestInfo);
     var id = arguments.remove(idField);
-    return await service.update(id, arguments['data'], params) as Value;
+    return await service.update(id, arguments['data'] as Value, params);
   };
 }
 
@@ -107,13 +108,13 @@ GraphQLFieldResolver<Value, Serialized>
 /// The arguments passed to the resolver will be forwarded to the service, and the
 /// service will receive [Providers.graphql].
 GraphQLFieldResolver<Value, Serialized>
-    resolveViaServiceRemove<Value, Serialized>(Service service,
+    resolveViaServiceRemove<Value, Serialized>(Service<dynamic, Value> service,
         {String idField: 'id'}) {
   return (_, arguments) async {
     var _requestInfo = _fetchRequestInfo(arguments);
     var params = {'query': arguments, 'provider': Providers.graphQL}
       ..addAll(_requestInfo);
     var id = arguments.remove(idField);
-    return await service.remove(id, params) as Value;
+    return await service.remove(id, params);
   };
 }