Migrated Schema Middleware (#2307)

src/HotChocolate/AspNetCore/src/AspNetCore/Extensions/HttpEndpointRouteBuilderExtensions.cs

@@ -25,18 +25,20 @@ public static class HttpEndpointRouteBuilderExtensions
                 throw new ArgumentNullException(nameof(endpointRouteBuilder));
             }
 
-            IApplicationBuilder applicationBuilder =
+            IApplicationBuilder requestPipeline =
                 endpointRouteBuilder.CreateApplicationBuilder();
 
-            applicationBuilder.UseMiddleware<WebSocketSubscriptionMiddleware>(
+            requestPipeline.UseMiddleware<WebSocketSubscriptionMiddleware>(
                 schemaName.HasValue ? schemaName : Schema.DefaultName);
-            applicationBuilder.UseMiddleware<HttpPostMiddleware>(
+            requestPipeline.UseMiddleware<HttpPostMiddleware>(
                 schemaName.HasValue ? schemaName : Schema.DefaultName);
-            applicationBuilder.UseMiddleware<HttpGetMiddleware>(
+            requestPipeline.UseMiddleware<HttpGetSchemaMiddleware>(
+                schemaName.HasValue ? schemaName : Schema.DefaultName);
+            requestPipeline.UseMiddleware<HttpGetMiddleware>(
                 schemaName.HasValue ? schemaName : Schema.DefaultName);
 
             return endpointRouteBuilder
-                .Map(pattern, applicationBuilder.Build())
+                .Map(pattern, requestPipeline.Build())
                 .WithDisplayName("Hot Chocolate GraphQL Pipeline");
         }
     }

src/HotChocolate/AspNetCore/src/AspNetCore/HttpGetSchemaMiddleware.cs

@@ -0,0 +1,62 @@
+using System.IO;
+using System.Threading.Tasks;
+using Microsoft.AspNetCore.Http;
+using HotChocolate.AspNetCore.Utilities;
+using HotChocolate.Execution;
+using HttpRequestDelegate = Microsoft.AspNetCore.Http.RequestDelegate;
+
+namespace HotChocolate.AspNetCore
+{
+    public class HttpGetSchemaMiddleware : MiddlewareBase
+    {
+
+        public HttpGetSchemaMiddleware(
+            HttpRequestDelegate next,
+            IRequestExecutorResolver executorResolver,
+            IHttpResultSerializer resultSerializer,
+            NameString schemaName)
+            : base(next, executorResolver, resultSerializer, schemaName)
+        {
+        }
+
+        public async Task InvokeAsync(HttpContext context)
+        {
+            if (HttpMethods.IsGet(context.Request.Method) &&
+                context.Request.Query.ContainsKey("SDL"))
+            {
+                await HandleRequestAsync(context);
+            }
+            else
+            {
+                // if the request is not a get request or if the content type is not correct
+                // we will just invoke the next middleware and do nothing.
+                await NextAsync(context);
+            }
+        }
+
+        private async Task HandleRequestAsync(HttpContext context)
+        {
+            IRequestExecutor requestExecutor = await GetExecutorAsync(context.RequestAborted);
+
+            string fileName =
+                requestExecutor.Schema.Name.IsEmpty ||
+                requestExecutor.Schema.Name.Equals(Schema.DefaultName)
+                    ? "schema.graphql"
+                    : requestExecutor.Schema.Name + ".schema.graphql";
+
+            context.Response.ContentType = ContentType.GraphQL;
+            context.Response.Headers.Add(
+                "Content-Disposition",
+                new[] { $"attachment; filename=\"{fileName}\"" });
+
+            await using var memoryStream = new MemoryStream();
+            await using var streamWriter = new StreamWriter(memoryStream);
+
+            SchemaSerializer.Serialize(requestExecutor.Schema, streamWriter);
+            await streamWriter.FlushAsync().ConfigureAwait(false);
+
+            memoryStream.Seek(0, SeekOrigin.Begin);
+            await memoryStream.CopyToAsync(context.Response.Body).ConfigureAwait(false);
+        }
+    }
+}

src/HotChocolate/AspNetCore/test/AspNetCore.Tests/HttpGetSchemaMiddlewareTests.cs

@@ -0,0 +1,35 @@
+using System.Net;
+using System.Net.Http;
+using System.Threading.Tasks;
+using HotChocolate.AspNetCore.Utilities;
+using Microsoft.AspNetCore.TestHost;
+using Snapshooter.Xunit;
+using Xunit;
+
+namespace HotChocolate.AspNetCore
+{
+    public class HttpGetSchemaMiddlewareTests : ServerTestBase
+    {
+        public HttpGetSchemaMiddlewareTests(TestServerFactory serverFactory)
+            : base(serverFactory)
+        {
+        }
+
+        [Fact]
+        public async Task Download_GraphQL_SDL()
+        {
+            // arrange
+            TestServer server = CreateStarWarsServer();
+            var url = TestServerExtensions.CreateUrl("/graphql?sdl");
+            var request = new HttpRequestMessage(HttpMethod.Get, url);
+
+            // act
+            HttpResponseMessage response = await server.CreateClient().SendAsync(request);
+
+            // assert
+            Assert.Equal(HttpStatusCode.OK, response.StatusCode);
+            var result = await response.Content.ReadAsStringAsync();
+            result.MatchSnapshot();
+        }
+    }
+}

src/HotChocolate/AspNetCore/test/AspNetCore.Tests/Utilities/ServerTestBase.cs

@@ -31,7 +31,7 @@ public ServerTestBase(TestServerFactory serverFactory)
                 app => app
                     .UseWebSockets()
                     .UseRouting()
-                    .UseEndpoints(endpoints => 
+                    .UseEndpoints(endpoints =>
                     {
                         endpoints.MapGraphQL(pattern);
                         endpoints.MapGraphQL("evict", "evict");

src/HotChocolate/AspNetCore/test/AspNetCore.Tests/__snapshots__/HttpGetSchemaMiddlewareTests.Download_GraphQL_SDL.snap

@@ -0,0 +1,131 @@
+schema {
+  query: Query
+  mutation: Mutation
+  subscription: Subscription
+}
+
+interface Character {
+  id: ID!
+  name: String
+  friends(first: PaginationAmount after: String last: PaginationAmount before: String): CharacterConnection
+  appearsIn: [Episode]
+  height(unit: Unit): Float
+}
+
+"A connection to a list of items."
+type CharacterConnection {
+  "Information to aid in pagination."
+  pageInfo: PageInfo!
+  "A list of edges."
+  edges: [CharacterEdge!]
+  "A flattened list of the nodes."
+  nodes: [Character]
+  totalCount: Int!
+}
+
+"An edge in a connection."
+type CharacterEdge {
+  "A cursor for use in pagination."
+  cursor: String!
+  "The item at the end of the edge."
+  node: Character
+}
+
+type Droid implements Character {
+  id: ID!
+  appearsIn: [Episode]
+  friends(first: PaginationAmount after: String last: PaginationAmount before: String): CharacterConnection
+  height(unit: Unit): Float
+  name: String
+  primaryFunction: String
+}
+
+type Human implements Character {
+  id: ID!
+  appearsIn: [Episode]
+  friends(first: PaginationAmount after: String last: PaginationAmount before: String): CharacterConnection
+  otherHuman: Human
+  height(unit: Unit): Float
+  name: String
+  homePlanet: String
+}
+
+type Mutation {
+  createReview(episode: Episode! review: ReviewInput!): Review!
+}
+
+"Information about pagination in a connection."
+type PageInfo {
+  "Indicates whether more edges exist following the set defined by the clients arguments."
+  hasNextPage: Boolean!
+  "Indicates whether more edges exist prior the set defined by the clients arguments."
+  hasPreviousPage: Boolean!
+  "When paginating backwards, the cursor to continue."
+  startCursor: String
+  "When paginating forwards, the cursor to continue."
+  endCursor: String
+}
+
+type Query {
+  hero(episode: Episode! = NEW_HOPE): Character
+  heroes(episodes: [Episode!]): [Character!]
+  character(characterIds: [String]): [Character!]!
+  search(text: String): [SearchResult]
+  human(id: String): Human
+  droid(id: String): Droid
+  time: Long!
+  evict: Boolean!
+}
+
+type Review {
+  stars: Int!
+  commentary: String
+}
+
+type Starship {
+  id: String
+  name: String
+  length: Float!
+}
+
+type Subscription {
+  onReview(episode: Episode!): Review!
+}
+
+union SearchResult = Starship | Human | Droid
+
+input ReviewInput {
+  stars: Int!
+  commentary: String
+}
+
+enum Episode {
+  NEW_HOPE
+  EMPIRE
+  JEDI
+}
+
+enum Unit {
+  FOOT
+  METERS
+}
+
+"The `Boolean` scalar type represents `true` or `false`."
+scalar Boolean
+
+"The `Float` scalar type represents signed double-precision fractional values as specified by [IEEE 754](http:\/\/en.wikipedia.org\/wiki\/IEEE_floating_point)."
+scalar Float
+
+"The `ID` scalar type represents a unique identifier, often used to refetch an object or as key for a cache. The ID type appears in a JSON response as a String; however, it is not intended to be human-readable. When expected as an input type, any string (such as `\"4\"`) or integer (such as `4`) input value will be accepted as an ID."
+scalar ID
+
+"The `Int` scalar type represents non-fractional signed whole numeric values. Int can represent values between -(2^31) and 2^31 - 1."
+scalar Int
+
+"The `Long` scalar type represents non-fractional signed whole 64-bit numeric values. Long can represent values between -(2^63) and 2^63 - 1."
+scalar Long
+
+scalar PaginationAmount
+
+"The `String` scalar type represents textual data, represented as UTF-8 character sequences. The String type is most often used by GraphQL to represent free-form human-readable text."
+scalar String