Add documentation to example types

angel_graphql/example/main.dart

@@ -19,16 +19,20 @@ main() async {
 
   var todoService = app.use('api/todos', new MapService()) as Service;
 
-  var api = objectType('api', fields: [
+  var api = objectType(
+    'Query',
+    description: 'A simple API that manages your to-do list.',
+    fields: [
       field(
         'todo',
-      type: listType(objectTypeFromDartType(Todo)),
+        type: listType(objectTypeFromDartType(Todo).nonNullable()),
         resolve: resolveFromService(todoService),
         arguments: [
           new GraphQLFieldArgument('id', graphQLId),
         ],
       ),
-  ]);
+    ],
+  );
 
   var schema = graphQLSchema(query: api);
 
@@ -37,7 +41,8 @@ main() async {
 
   await todoService.create({'text': 'Clean your room!', 'completed': true});
   await todoService.create({'text': 'Take out the trash', 'completed': false});
-  await todoService.create({'text': 'Become a billionaire at the age of 5', 'completed': false});
+  await todoService.create(
+      {'text': 'Become a billionaire at the age of 5', 'completed': false});
 
   var server = await http.startServer('127.0.0.1', 3000);
   var uri =
@@ -48,6 +53,7 @@ main() async {
 }
 
 @serializable
+@GraphQLDocumentation(description: 'A task that might not be completed yet. **Yay! Markdown!**')
 class Todo extends Model {
   String text;
 

graphql_schema/lib/src/gen.dart

@@ -11,7 +11,11 @@ GraphQLObjectType objectType(String name,
 GraphQLField<T, Serialized> field<T, Serialized>(String name,
     {Iterable<GraphQLFieldArgument<T, Serialized>> arguments: const [],
     GraphQLFieldResolver<T, Serialized> resolve,
-    GraphQLType<T, Serialized> type}) {
+    GraphQLType<T, Serialized> type,
+    String deprecationReason}) {
   return new GraphQLField(name,
-      arguments: arguments, resolve: resolve, type: type);
+      arguments: arguments,
+      resolve: resolve,
+      type: type,
+      deprecationReason: deprecationReason);
 }

graphql_schema/lib/src/schema.dart

@@ -1,13 +1,21 @@
 library graphql_schema.src.schema;
 
 import 'dart:async';
+
 import 'package:meta/meta.dart';
+
 part 'argument.dart';
+
 part 'field.dart';
+
 part 'gen.dart';
+
 part 'object_type.dart';
+
 part 'scalar.dart';
+
 part 'type.dart';
+
 part 'validation_result.dart';
 
 class GraphQLSchema {
@@ -19,8 +27,11 @@ class GraphQLSchema {
 }
 
 GraphQLSchema graphQLSchema(
-        {@required GraphQLObjectType query, GraphQLObjectType mutation, GraphQLObjectType subscription}) =>
-    new GraphQLSchema(query: query, mutation: mutation, subscription: subscription);
+        {@required GraphQLObjectType query,
+        GraphQLObjectType mutation,
+        GraphQLObjectType subscription}) =>
+    new GraphQLSchema(
+        query: query, mutation: mutation, subscription: subscription);
 
 /// A default resolver that always returns `null`.
 resolveToNull(_, __) => null;
@@ -31,3 +42,10 @@ class GraphQLException extends FormatException {
   @override
   String toString() => 'GraphQL exception: $message';
 }
+
+/// A metadata annotation used to provide documentation to `package:graphql_server`.
+class GraphQLDocumentation {
+  final String description;
+
+  const GraphQLDocumentation({this.description});
+}

graphql_server/lib/mirrors.dart

@@ -65,6 +65,7 @@ GraphQLObjectType objectTypeFromClassMirror(ClassMirror mirror) {
   return objectType(
     MirrorSystem.getName(mirror.simpleName),
     fields: fields,
+    description: _getDescription(mirror.metadata),
   );
 }
 
@@ -83,6 +84,7 @@ GraphQLField fieldFromGetter(
   return field(
     nameString,
     type: type,
+    deprecationReason: _getDeprecationReason(mirror.metadata),
     resolve: (obj, _) {
       if (obj is Map && exclude?.canSerialize != true) {
         return obj[nameString];
@@ -152,3 +154,27 @@ bool _autoNames(ClassMirror clazz) {
 
   return false;
 }
+
+String _getDeprecationReason(List<InstanceMirror> metadata) {
+  for (var obj in metadata) {
+    if (obj.reflectee is Deprecated) {
+      var expires = (obj.reflectee as Deprecated).expires;
+
+      if (expires == deprecated.expires) {
+        return 'Expires after $expires';
+      } else {
+        deprecated.expires;
+      }
+    }
+  }
+}
+
+String _getDescription(List<InstanceMirror> metadata) {
+  for (var obj in metadata) {
+    if (obj.reflectee is GraphQLDocumentation) {
+      return (obj.reflectee as GraphQLDocumentation).description;
+    }
+  }
+
+  return null;
+}