Implement POST with application/json in GraphQL Middleware. (#24)

ttu · Jul 17, 2018 · 223627e · 223627e
1 parent 887eaab
commit 223627e
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Showing 3 changed files with 99 additions and 10 deletions.
diff --git a/FakeServer.Test/FakeServerSpecs.cs b/FakeServer.Test/FakeServerSpecs.cs
@@ -1040,13 +1040,57 @@ public async Task PostGraphQL_Filter_Bool()
         }
 
         [Fact]
-        public async Task PostGraphQL_Error()
+        public async Task PostGraphQL_Json()
+        {
+            using (var client = new HttpClient())
+            {
+                var content = new StringContent(@"{""query"":""{users}""}", Encoding.UTF8, "application/json");
+                var result = await client.PostAsync($"{_fixture.BaseUrl}/graphql", content);
+
+                Assert.Equal(HttpStatusCode.OK, result.StatusCode);
+
+                var data = JsonConvert.DeserializeObject<JObject>(await result.Content.ReadAsStringAsync());
+
+                Assert.NotNull(data["data"]);
+                Assert.Null(data["errors"]);
+            }
+        }
+
+        [Fact]
+        public async Task PostGraphQL_Error_InvalidJson()
         {
             using (var client = new HttpClient())
             {
                 var content = new StringContent("{ users }", Encoding.UTF8, "application/json");
                 var result = await client.PostAsync($"{_fixture.BaseUrl}/graphql", content);
+                Assert.Equal(HttpStatusCode.BadRequest, result.StatusCode);
+            }
+        }
+
+        [Fact]
+        public async Task PostGraphQL_Error_MissingQuery()
+        {
+            using (var client = new HttpClient())
+            {
+                var content = new StringContent(@"{ }", Encoding.UTF8, "application/json");
+                var result = await client.PostAsync($"{_fixture.BaseUrl}/graphql", content);
+                Assert.Equal(HttpStatusCode.BadRequest, result.StatusCode);
+            }
+        }
+
+        [Fact]
+        public async Task GetGraphQL_NotImplemented()
+        {
+            using (var client = new HttpClient())
+            {
+                var result = await client.GetAsync($"{_fixture.BaseUrl}/graphql?query={{users}}");
+
                 Assert.Equal(HttpStatusCode.NotImplemented, result.StatusCode);
+
+                var data = JsonConvert.DeserializeObject<JObject>(await result.Content.ReadAsStringAsync());
+
+                Assert.Null(data["data"]);
+                Assert.NotNull(data["errors"]);
             }
         }
     }

diff --git a/FakeServer/GraphQL/GraphQLMiddleware.cs b/FakeServer/GraphQL/GraphQLMiddleware.cs
@@ -3,6 +3,8 @@
 using JsonFlatFileDataStore;
 using Microsoft.AspNetCore.Http;
 using Newtonsoft.Json;
+using System;
+using System.Collections.Generic;
 using System.IO;
 using System.Linq;
 using System.Net;
@@ -16,6 +18,7 @@ public class GraphQLMiddleware
         private readonly IDataStore _datastore;
         private readonly IMessageBus _bus;
         private readonly bool _authenticationEnabled;
+        private readonly string[] _allowedTypes = new[] { "application/graphql", "application/json" };
 
         public GraphQLMiddleware(RequestDelegate next, IDataStore datastore, IMessageBus bus, bool authenticationEnabled)
         {
@@ -28,7 +31,7 @@ public GraphQLMiddleware(RequestDelegate next, IDataStore datastore, IMessageBus
         public async Task Invoke(HttpContext context)
         {
             // POST application/graphql body is query
-            // TODO: POST application/json and { "query": "..." }
+            // POST application/json and { "query": "..." }
             // TODO: POST /graphql?query={users{name}}
             // TODO: GET /graphql?query={users{name}}
 
@@ -44,25 +47,29 @@ public async Task Invoke(HttpContext context)
                 return;
             }
 
-            if (context.Request.Method != "POST" || !context.Request.ContentType.Contains("application/graphql"))
+            if (context.Request.Method != "POST" || !_allowedTypes.Any(context.Request.ContentType.Contains))
             {
                 context.Response.StatusCode = (int)HttpStatusCode.NotImplemented;
                 await context.Response.WriteAsync(JsonConvert.SerializeObject(new { errors = new[] { "Not implemented" } }));
                 return;
             }
 
-            var query = string.Empty;
+            GraphQLResult result = null;
 
-            using (var streamReader = new StreamReader(context.Request.Body))
+            var (success, query, error) = await ParseQuery(context);
+
+            if (!success)
             {
-                query = await streamReader.ReadToEndAsync().ConfigureAwait(true);
+                result = new GraphQLResult { Errors = new List<string> { error } };
             }
+            else
+            {
+                var toReplace = new[] { "\r\n", "\\r\\n", "\\n", "\n" };
 
-            var toReplace = new[] { "\r\n", "\\r\\n", "\\n", "\n" };
-
-            query = toReplace.Aggregate(query, (acc, curr) => acc.Replace(curr, ""));
+                query = toReplace.Aggregate(query, (acc, curr) => acc.Replace(curr, ""));
 
-            var result = await GraphQL.HandleQuery(query, _datastore);
+                result = await GraphQL.HandleQuery(query, _datastore);
+            }
 
             var json = result.Errors?.Any() == true
                             ? JsonConvert.SerializeObject(new { data = result.Data, errors = result.Errors })
@@ -75,5 +82,38 @@ public async Task Invoke(HttpContext context)
 
             await context.Response.WriteAsync(json);
         }
+
+        private static async Task<(bool success, string body, string error)> ParseQuery(HttpContext context)
+        {
+            string body;
+
+            using (var streamReader = new StreamReader(context.Request.Body))
+            {
+                body = await streamReader.ReadToEndAsync().ConfigureAwait(true);
+            }
+
+            if (context.Request.ContentType.StartsWith("application/graphql"))
+            {
+                return (true, body, null);
+            }
+
+            dynamic jsonBody;
+
+            try
+            {
+                jsonBody = JsonConvert.DeserializeObject(body);
+            }
+            catch (Exception e)
+            {
+                return (false, null, e.Message);
+            }
+
+            if (jsonBody.query is null)
+            {
+                return (false, null, "Missing query property in json.");
+            }    
+
+            return (true, jsonBody.query, null);
+        }
     }
 }
diff --git a/README.md b/README.md
@@ -926,13 +926,18 @@ Delay value is milliseconds. Default value is 2000ms.
 ### GraphQL
 
 GraphQL implementation is experimental and supports only basic queries and mutations. At the moment this is a good way to compare simple GraphQL and REST queries.
+`/graphql` endpoint accepts requests with `application/graphql` or `application/json` content type. If the first, request body is GraphQL query string, whereas if the latter, request body is expected to be a valid JSON with parameter `query` containing the GraphQL query string.
 
 ```
 > POST /graphql
 
 Content-type: application/graphql
 Body: [query/mutation]
 
+OR
+
+Content-type: application/json
+Body: { "query": "[query/mutation]" }
 
 200 OK              : Query/mutation successful 
 400 Bad Request     : Query/mutation contains errors