fix: application/graphql-response+json status codes

Previously these would always return 200 success, but must return 400's for spec compliance. Also improves result error formatting

Author: NeedleInAJayStack

Sources/GraphQLHummingbird/Coding/GraphQLJSONEncoder+encode.swift

@@ -7,11 +7,24 @@ extension GraphQLJSONEncoder: @retroactive ResponseEncoder {
     ///   - value: Value to encode
     ///   - request: Request used to generate response
     ///   - context: Request context
-    public func encode(_ value: some Encodable, from _: Request, context _: some RequestContext) throws -> Response {
+    public func encode(_ value: some Encodable, from request: Request, context: some RequestContext) throws -> Response {
+        try encode(value, status: .ok, from: request, context: context)
+    }
+}
+
+extension GraphQLJSONEncoder {
+    /// Extend GraphQLJSONEncoder to support generating a ``HummingbirdCore/Response``. Sets body and header values. Similar to the
+    /// `ResponseEncoder`-required version, except it allows setting the reponse status as well.
+    /// - Parameters:
+    ///   - value: Value to encode
+    ///   - status: The status of the response
+    ///   - request: Request used to generate response
+    ///   - context: Request context
+    func encode(_ value: some Encodable, status: HTTPResponse.Status, from _: Request, context _: some RequestContext) throws -> Response {
         let data = try encode(value)
         let buffer = ByteBuffer(bytes: data)
         return Response(
-            status: .ok,
+            status: status,
             headers: [
                 .contentType: "\(MediaType.applicationJsonGraphQL); charset=utf-8",
                 .contentLength: data.count.description,
@@ -20,3 +33,20 @@ extension GraphQLJSONEncoder: @retroactive ResponseEncoder {
         )
     }
 }
+
+extension GraphQLJSONEncoder {
+    /// Overload for GraphQLJSONEncoder to support generating a ``HummingbirdCore/Response`` from a GraphQLResult. Sets body, headers, and status, according to [GraphQL-over-HTTP spec](https://github.com/graphql/graphql-over-http/blob/main/spec/GraphQLOverHTTP.md#applicationgraphql-responsejson).
+    /// - Parameters:
+    ///   - value: GraphQLResult to encode
+    ///   - request: Request used to generate response
+    ///   - context: Request context
+    func encode(_ value: GraphQLResult, from request: Request, context: some RequestContext) throws -> Response {
+        var status = HTTPResponse.Status.ok
+        // We must return `bad request` with the content if there were failures preventing a partial result
+        // https://github.com/graphql/graphql-over-http/blob/main/spec/GraphQLOverHTTP.md#applicationgraphql-responsejson
+        if value.data == nil {
+            status = .badRequest
+        }
+        return try encode(value, status: status, from: request, context: context)
+    }
+}

Sources/GraphQLHummingbird/HTTP/GraphQLHandler+HTTP.swift

@@ -25,7 +25,7 @@ extension GraphQLHandler {
             throw HTTPError(.methodNotAllowed, message: "Mutations using GET are disallowed")
         }
         let graphqlContext = try await computeContext(request, context)
-        let result = try await execute(
+        let result = await execute(
             graphQLRequest: graphQLRequest,
             context: graphqlContext,
             additionalValidationRules: config.additionalValidationRules
@@ -43,15 +43,23 @@ extension GraphQLHandler {
         let graphQLRequest: GraphQLRequest
         switch mediaType {
         case .applicationJson, .applicationJsonGraphQL:
-            graphQLRequest = try await JSONDecoder().decode(GraphQLRequest.self, from: request, context: context)
+            do {
+                graphQLRequest = try await JSONDecoder().decode(GraphQLRequest.self, from: request, context: context)
+            } catch {
+                throw HTTPError(.badRequest, message: error.localizedDescription)
+            }
         case .applicationUrlEncoded:
-            graphQLRequest = try await URLEncodedFormDecoder().decode(GraphQLRequest.self, from: request, context: context)
+            do {
+                graphQLRequest = try await URLEncodedFormDecoder().decode(GraphQLRequest.self, from: request, context: context)
+            } catch {
+                throw HTTPError(.badRequest, message: error.localizedDescription)
+            }
         default:
             throw HTTPError(.unsupportedMediaType)
         }
 
         let graphqlContext = try await computeContext(request, context)
-        let result = try await execute(
+        let result = await execute(
             graphQLRequest: graphQLRequest,
             context: graphqlContext,
             additionalValidationRules: config.additionalValidationRules
@@ -63,7 +71,7 @@ extension GraphQLHandler {
         graphQLRequest: GraphQLRequest,
         context: GraphQLContext,
         additionalValidationRules: [@Sendable (ValidationContext) -> Visitor]
-    ) async throws -> GraphQLResult {
+    ) async -> GraphQLResult {
         // https://github.com/graphql/graphql-over-http/blob/main/spec/GraphQLOverHTTP.md#validation
         let validationRules = GraphQL.specifiedRules + additionalValidationRules
 
@@ -79,9 +87,11 @@ extension GraphQLHandler {
                 operationName: graphQLRequest.operationName,
                 validationRules: validationRules
             )
-        } catch {
+        } catch let error as GraphQLError {
             // This indicates a request parsing error
-            throw HTTPError(.badRequest, message: error.localizedDescription)
+            return GraphQLResult(data: nil, errors: [error])
+        } catch {
+            return GraphQLResult(data: nil, errors: [GraphQLError(message: error.localizedDescription)])
         }
         return result
     }