Update GQLGen and break up the schema.graphql file

vendor/github.com/99designs/gqlgen/graphql/context.go

@@ -12,6 +12,7 @@ import (
 type Resolver func(ctx context.Context) (res interface{}, err error)
 type FieldMiddleware func(ctx context.Context, next Resolver) (res interface{}, err error)
 type RequestMiddleware func(ctx context.Context, next func(ctx context.Context) []byte) []byte
+type ComplexityLimitFunc func(ctx context.Context) int
 
 type RequestContext struct {
 	RawQuery  string
@@ -71,12 +72,10 @@ const (
 )
 
 func GetRequestContext(ctx context.Context) *RequestContext {
-	val := ctx.Value(request)
-	if val == nil {
-		return nil
+	if val, ok := ctx.Value(request).(*RequestContext); ok {
+		return val
 	}
-
-	return val.(*RequestContext)
+	return nil
 }
 
 func WithRequestContext(ctx context.Context, rc *RequestContext) context.Context {
@@ -95,6 +94,8 @@ type ResolverContext struct {
 	Index *int
 	// The result object of resolver
 	Result interface{}
+	// IsMethod indicates if the resolver is a method
+	IsMethod bool
 }
 
 func (r *ResolverContext) Path() []interface{} {
@@ -117,8 +118,10 @@ func (r *ResolverContext) Path() []interface{} {
 }
 
 func GetResolverContext(ctx context.Context) *ResolverContext {
-	val, _ := ctx.Value(resolver).(*ResolverContext)
-	return val
+	if val, ok := ctx.Value(resolver).(*ResolverContext); ok {
+		return val
+	}
+	return nil
 }
 
 func WithResolverContext(ctx context.Context, rc *ResolverContext) context.Context {
@@ -132,6 +135,24 @@ func CollectFieldsCtx(ctx context.Context, satisfies []string) []CollectedField
 	return CollectFields(ctx, resctx.Field.Selections, satisfies)
 }
 
+// CollectAllFields returns a slice of all GraphQL field names that were selected for the current resolver context.
+// The slice will contain the unique set of all field names requested regardless of fragment type conditions.
+func CollectAllFields(ctx context.Context) []string {
+	resctx := GetResolverContext(ctx)
+	collected := CollectFields(ctx, resctx.Field.Selections, nil)
+	uniq := make([]string, 0, len(collected))
+Next:
+	for _, f := range collected {
+		for _, name := range uniq {
+			if name == f.Name {
+				continue Next
+			}
+		}
+		uniq = append(uniq, f.Name)
+	}
+	return uniq
+}
+
 // Errorf sends an error string to the client, passing it through the formatter.
 func (c *RequestContext) Errorf(ctx context.Context, format string, args ...interface{}) {
 	c.errorsMu.Lock()

vendor/github.com/99designs/gqlgen/graphql/error.go

@@ -14,7 +14,9 @@ type ExtendedError interface {
 
 func DefaultErrorPresenter(ctx context.Context, err error) *gqlerror.Error {
 	if gqlerr, ok := err.(*gqlerror.Error); ok {
-		gqlerr.Path = GetResolverContext(ctx).Path()
+		if gqlerr.Path == nil {
+			gqlerr.Path = GetResolverContext(ctx).Path()
+		}
 		return gqlerr
 	}
 

vendor/github.com/99designs/gqlgen/graphql/exec.go

@@ -16,6 +16,9 @@ type ExecutableSchema interface {
 	Subscription(ctx context.Context, op *ast.OperationDefinition) func() *Response
 }
 
+// CollectFields returns the set of fields from an ast.SelectionSet where all collected fields satisfy at least one of the GraphQL types
+// passed through satisfies. Providing an empty or nil slice for satisfies will return collect all fields regardless of fragment
+// type conditions.
 func CollectFields(ctx context.Context, selSet ast.SelectionSet, satisfies []string) []CollectedField {
 	return collectFields(GetRequestContext(ctx), selSet, satisfies, map[string]bool{})
 }
@@ -35,7 +38,10 @@ func collectFields(reqCtx *RequestContext, selSet ast.SelectionSet, satisfies []
 
 			f.Selections = append(f.Selections, sel.SelectionSet...)
 		case *ast.InlineFragment:
-			if !shouldIncludeNode(sel.Directives, reqCtx.Variables) || !instanceOf(sel.TypeCondition, satisfies) {
+			if !shouldIncludeNode(sel.Directives, reqCtx.Variables) {
+				continue
+			}
+			if len(satisfies) > 0 && !instanceOf(sel.TypeCondition, satisfies) {
 				continue
 			}
 			for _, childField := range collectFields(reqCtx, sel.SelectionSet, satisfies, visited) {
@@ -59,7 +65,7 @@ func collectFields(reqCtx *RequestContext, selSet ast.SelectionSet, satisfies []
 				panic(fmt.Errorf("missing fragment %s", fragmentName))
 			}
 
-			if !instanceOf(fragment.TypeCondition, satisfies) {
+			if len(satisfies) > 0 && !instanceOf(fragment.TypeCondition, satisfies) {
 				continue
 			}
 

vendor/github.com/99designs/gqlgen/graphql/id.go

@@ -34,3 +34,24 @@ func UnmarshalID(v interface{}) (string, error) {
 		return "", fmt.Errorf("%T is not a string", v)
 	}
 }
+
+func MarshalIntID(i int) Marshaler {
+	return WriterFunc(func(w io.Writer) {
+		writeQuotedString(w, strconv.Itoa(i))
+	})
+}
+
+func UnmarshalIntID(v interface{}) (int, error) {
+	switch v := v.(type) {
+	case string:
+		return strconv.Atoi(v)
+	case int:
+		return v, nil
+	case int64:
+		return int(v), nil
+	case json.Number:
+		return strconv.Atoi(string(v))
+	default:
+		return 0, fmt.Errorf("%T is not an int", v)
+	}
+}

vendor/github.com/99designs/gqlgen/graphql/int.go

@@ -27,3 +27,53 @@ func UnmarshalInt(v interface{}) (int, error) {
 		return 0, fmt.Errorf("%T is not an int", v)
 	}
 }
+
+func MarshalInt64(i int64) Marshaler {
+	return WriterFunc(func(w io.Writer) {
+		io.WriteString(w, strconv.FormatInt(i, 10))
+	})
+}
+
+func UnmarshalInt64(v interface{}) (int64, error) {
+	switch v := v.(type) {
+	case string:
+		return strconv.ParseInt(v, 10, 64)
+	case int:
+		return int64(v), nil
+	case int64:
+		return v, nil
+	case json.Number:
+		return strconv.ParseInt(string(v), 10, 64)
+	default:
+		return 0, fmt.Errorf("%T is not an int", v)
+	}
+}
+
+func MarshalInt32(i int32) Marshaler {
+	return WriterFunc(func(w io.Writer) {
+		io.WriteString(w, strconv.FormatInt(int64(i), 10))
+	})
+}
+
+func UnmarshalInt32(v interface{}) (int32, error) {
+	switch v := v.(type) {
+	case string:
+		iv, err := strconv.ParseInt(v, 10, 32)
+		if err != nil {
+			return 0, err
+		}
+		return int32(iv), nil
+	case int:
+		return int32(v), nil
+	case int64:
+		return int32(v), nil
+	case json.Number:
+		iv, err := strconv.ParseInt(string(v), 10, 32)
+		if err != nil {
+			return 0, err
+		}
+		return int32(iv), nil
+	default:
+		return 0, fmt.Errorf("%T is not an int", v)
+	}
+}

vendor/github.com/99designs/gqlgen/graphql/introspection/type.go

@@ -62,9 +62,9 @@ func (t *Type) Description() string {
 
 func (t *Type) Fields(includeDeprecated bool) []Field {
 	if t.def == nil || (t.def.Kind != ast.Object && t.def.Kind != ast.Interface) {
-		return nil
+		return []Field{}
 	}
-	var fields []Field
+	fields := []Field{}
 	for _, f := range t.def.Fields {
 		if strings.HasPrefix(f.Name, "__") {
 			continue
@@ -93,10 +93,10 @@ func (t *Type) Fields(includeDeprecated bool) []Field {
 
 func (t *Type) InputFields() []InputValue {
 	if t.def == nil || t.def.Kind != ast.InputObject {
-		return nil
+		return []InputValue{}
 	}
 
-	var res []InputValue
+	res := []InputValue{}
 	for _, f := range t.def.Fields {
 		res = append(res, InputValue{
 			Name:         f.Name,
@@ -118,10 +118,10 @@ func defaultValue(value *ast.Value) *string {
 
 func (t *Type) Interfaces() []Type {
 	if t.def == nil || t.def.Kind != ast.Object {
-		return nil
+		return []Type{}
 	}
 
-	var res []Type
+	res := []Type{}
 	for _, intf := range t.def.Interfaces {
 		res = append(res, *WrapTypeFromDef(t.schema, t.schema.Types[intf]))
 	}
@@ -131,10 +131,10 @@ func (t *Type) Interfaces() []Type {
 
 func (t *Type) PossibleTypes() []Type {
 	if t.def == nil || (t.def.Kind != ast.Interface && t.def.Kind != ast.Union) {
-		return nil
+		return []Type{}
 	}
 
-	var res []Type
+	res := []Type{}
 	for _, pt := range t.schema.GetPossibleTypes(t.def) {
 		res = append(res, *WrapTypeFromDef(t.schema, pt))
 	}
@@ -143,10 +143,10 @@ func (t *Type) PossibleTypes() []Type {
 
 func (t *Type) EnumValues(includeDeprecated bool) []EnumValue {
 	if t.def == nil || t.def.Kind != ast.Enum {
-		return nil
+		return []EnumValue{}
 	}
 
-	var res []EnumValue
+	res := []EnumValue{}
 	for _, val := range t.def.EnumValues {
 		res = append(res, EnumValue{
 			Name:        val.Name,

vendor/github.com/99designs/gqlgen/graphql/root.go

@@ -0,0 +1,7 @@
+package graphql
+
+type Query struct{}
+
+type Mutation struct{}
+
+type Subscription struct{}

vendor/github.com/99designs/gqlgen/graphql/version.go

@@ -1,3 +1,3 @@
 package graphql
 
-const Version = "dev"
+const Version = "v0.8.2"

vendor/github.com/99designs/gqlgen/handler/graphql.go

@@ -7,6 +7,7 @@ import (
 	"io"
 	"net/http"
 	"strings"
+	"time"
 
 	"github.com/99designs/gqlgen/complexity"
 	"github.com/99designs/gqlgen/graphql"
@@ -25,15 +26,17 @@ type params struct {
 }
 
 type Config struct {
-	cacheSize            int
-	upgrader             websocket.Upgrader
-	recover              graphql.RecoverFunc
-	errorPresenter       graphql.ErrorPresenterFunc
-	resolverHook         graphql.FieldMiddleware
-	requestHook          graphql.RequestMiddleware
-	tracer               graphql.Tracer
-	complexityLimit      int
-	disableIntrospection bool
+	cacheSize                       int
+	upgrader                        websocket.Upgrader
+	recover                         graphql.RecoverFunc
+	errorPresenter                  graphql.ErrorPresenterFunc
+	resolverHook                    graphql.FieldMiddleware
+	requestHook                     graphql.RequestMiddleware
+	tracer                          graphql.Tracer
+	complexityLimit                 int
+	complexityLimitFunc             graphql.ComplexityLimitFunc
+	disableIntrospection            bool
+	connectionKeepAlivePingInterval time.Duration
 }
 
 func (c *Config) newRequestContext(es graphql.ExecutableSchema, doc *ast.QueryDocument, op *ast.OperationDefinition, query string, variables map[string]interface{}) *graphql.RequestContext {
@@ -60,7 +63,7 @@ func (c *Config) newRequestContext(es graphql.ExecutableSchema, doc *ast.QueryDo
 		reqCtx.Tracer = hook
 	}
 
-	if c.complexityLimit > 0 {
+	if c.complexityLimit > 0 || c.complexityLimitFunc != nil {
 		reqCtx.ComplexityLimit = c.complexityLimit
 		operationComplexity := complexity.Calculate(es, op, variables)
 		reqCtx.OperationComplexity = operationComplexity
@@ -108,6 +111,15 @@ func ComplexityLimit(limit int) Option {
 	}
 }
 
+// ComplexityLimitFunc allows you to define a function to dynamically set the maximum query complexity that is allowed
+// to be executed.
+// If a query is submitted that exceeds the limit, a 422 status code will be returned.
+func ComplexityLimitFunc(complexityLimitFunc graphql.ComplexityLimitFunc) Option {
+	return func(cfg *Config) {
+		cfg.complexityLimitFunc = complexityLimitFunc
+	}
+}
+
 // ResolverMiddleware allows you to define a function that will be called around every resolver,
 // useful for logging.
 func ResolverMiddleware(middleware graphql.FieldMiddleware) Option {
@@ -239,11 +251,23 @@ func CacheSize(size int) Option {
 	}
 }
 
+// WebsocketKeepAliveDuration allows you to reconfigure the keepalive behavior.
+// By default, keepalive is enabled with a DefaultConnectionKeepAlivePingInterval
+// duration. Set handler.connectionKeepAlivePingInterval = 0 to disable keepalive
+// altogether.
+func WebsocketKeepAliveDuration(duration time.Duration) Option {
+	return func(cfg *Config) {
+		cfg.connectionKeepAlivePingInterval = duration
+	}
+}
+
 const DefaultCacheSize = 1000
+const DefaultConnectionKeepAlivePingInterval = 25 * time.Second
 
 func GraphQL(exec graphql.ExecutableSchema, options ...Option) http.HandlerFunc {
 	cfg := &Config{
-		cacheSize: DefaultCacheSize,
+		cacheSize:                       DefaultCacheSize,
+		connectionKeepAlivePingInterval: DefaultConnectionKeepAlivePingInterval,
 		upgrader: websocket.Upgrader{
 			ReadBufferSize:  1024,
 			WriteBufferSize: 1024,
@@ -297,6 +321,7 @@ func (gh *graphqlHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
 		return
 	}
 
+	w.Header().Set("Content-Type", "application/json")
 	var reqParams params
 	switch r.Method {
 	case http.MethodGet:
@@ -318,7 +343,6 @@ func (gh *graphqlHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
 		w.WriteHeader(http.StatusMethodNotAllowed)
 		return
 	}
-	w.Header().Set("Content-Type", "application/json")
 
 	ctx := r.Context()
 
@@ -367,6 +391,10 @@ func (gh *graphqlHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
 		}
 	}()
 
+	if gh.cfg.complexityLimitFunc != nil {
+		reqCtx.ComplexityLimit = gh.cfg.complexityLimitFunc(ctx)
+	}
+
 	if reqCtx.ComplexityLimit > 0 && reqCtx.OperationComplexity > reqCtx.ComplexityLimit {
 		sendErrorf(w, http.StatusUnprocessableEntity, "operation has complexity %d, which exceeds the limit of %d", reqCtx.OperationComplexity, reqCtx.ComplexityLimit)
 		return

vendor/github.com/99designs/gqlgen/handler/playground.go

@@ -11,9 +11,12 @@ var page = template.Must(template.New("graphiql").Parse(`<!DOCTYPE html>
 	<meta charset=utf-8/>
 	<meta name="viewport" content="user-scalable=no, initial-scale=1.0, minimum-scale=1.0, maximum-scale=1.0, minimal-ui">
 	<link rel="shortcut icon" href="https://graphcool-playground.netlify.com/favicon.png">
-	<link rel="stylesheet" href="//cdn.jsdelivr.net/npm/graphql-playground-react@{{ .version }}/build/static/css/index.css"/>
-	<link rel="shortcut icon" href="//cdn.jsdelivr.net/npm/graphql-playground-react@{{ .version }}/build/favicon.png"/>
-	<script src="//cdn.jsdelivr.net/npm/graphql-playground-react@{{ .version }}/build/static/js/middleware.js"></script>
+	<link rel="stylesheet" href="https://cdn.jsdelivr.net/npm/graphql-playground-react@{{ .version }}/build/static/css/index.css" 
+		integrity="{{ .cssSRI }}" crossorigin="anonymous"/>
+	<link rel="shortcut icon" href="https://cdn.jsdelivr.net/npm/graphql-playground-react@{{ .version }}/build/favicon.png"
+		integrity="{{ .faviconSRI }}" crossorigin="anonymous"/>
+	<script src="https://cdn.jsdelivr.net/npm/graphql-playground-react@{{ .version }}/build/static/js/middleware.js"
+		integrity="{{ .jsSRI }}" crossorigin="anonymous"></script>
 	<title>{{.title}}</title>
 </head>
 <body>
@@ -42,10 +45,14 @@ var page = template.Must(template.New("graphiql").Parse(`<!DOCTYPE html>
 
 func Playground(title string, endpoint string) http.HandlerFunc {
 	return func(w http.ResponseWriter, r *http.Request) {
+		w.Header().Add("Content-Type", "text/html")
 		err := page.Execute(w, map[string]string{
-			"title":    title,
-			"endpoint": endpoint,
-			"version":  "1.7.8",
+			"title":      title,
+			"endpoint":   endpoint,
+			"version":    "1.7.20",
+			"cssSRI":     "sha256-cS9Vc2OBt9eUf4sykRWukeFYaInL29+myBmFDSa7F/U=",
+			"faviconSRI": "sha256-GhTyE+McTU79R4+pRO6ih+4TfsTOrpPwD8ReKFzb3PM=",
+			"jsSRI":      "sha256-4QG1Uza2GgGdlBL3RCBCGtGeZB6bDbsw8OltCMGeJsA=",
 		})
 		if err != nil {
 			panic(err)

vendor/github.com/99designs/gqlgen/handler/websocket.go

@@ -8,6 +8,7 @@ import (
 	"log"
 	"net/http"
 	"sync"
+	"time"
 
 	"github.com/99designs/gqlgen/graphql"
 	"github.com/gorilla/websocket"
@@ -28,7 +29,7 @@ const (
 	dataMsg                = "data"                 // Server -> Client
 	errorMsg               = "error"                // Server -> Client
 	completeMsg            = "complete"             // Server -> Client
-	//connectionKeepAliveMsg = "ka"                 // Server -> Client  TODO: keepalives
+	connectionKeepAliveMsg = "ka"                   // Server -> Client
 )
 
 type operationMessage struct {
@@ -38,13 +39,14 @@ type operationMessage struct {
 }
 
 type wsConnection struct {
-	ctx    context.Context
-	conn   *websocket.Conn
-	exec   graphql.ExecutableSchema
-	active map[string]context.CancelFunc
-	mu     sync.Mutex
-	cfg    *Config
-	cache  *lru.Cache
+	ctx             context.Context
+	conn            *websocket.Conn
+	exec            graphql.ExecutableSchema
+	active          map[string]context.CancelFunc
+	mu              sync.Mutex
+	cfg             *Config
+	cache           *lru.Cache
+	keepAliveTicker *time.Ticker
 
 	initPayload InitPayload
 }
@@ -112,6 +114,20 @@ func (c *wsConnection) write(msg *operationMessage) {
 }
 
 func (c *wsConnection) run() {
+	// We create a cancellation that will shutdown the keep-alive when we leave
+	// this function.
+	ctx, cancel := context.WithCancel(c.ctx)
+	defer cancel()
+
+	// Create a timer that will fire every interval to keep the connection alive.
+	if c.cfg.connectionKeepAlivePingInterval != 0 {
+		c.mu.Lock()
+		c.keepAliveTicker = time.NewTicker(c.cfg.connectionKeepAlivePingInterval)
+		c.mu.Unlock()
+
+		go c.keepAlive(ctx)
+	}
+
 	for {
 		message := c.readOp()
 		if message == nil {
@@ -144,6 +160,18 @@ func (c *wsConnection) run() {
 	}
 }
 
+func (c *wsConnection) keepAlive(ctx context.Context) {
+	for {
+		select {
+		case <-ctx.Done():
+			c.keepAliveTicker.Stop()
+			return
+		case <-c.keepAliveTicker.C:
+			c.write(&operationMessage{Type: connectionKeepAliveMsg})
+		}
+	}
+}
+
 func (c *wsConnection) subscribe(message *operationMessage) bool {
 	var reqParams params
 	if err := jsonDecode(bytes.NewReader(message.Payload), &reqParams); err != nil {

vendor/github.com/vektah/gqlparser/validator/schema.go

@@ -184,13 +184,19 @@ func validateDefinition(schema *Schema, def *Definition) *gqlerror.Error {
 		}
 	}
 
-	for _, intf := range def.Interfaces {
-		intDef := schema.Types[intf]
-		if intDef == nil {
-			return gqlerror.ErrorPosf(def.Position, "Undefined type %s.", strconv.Quote(intf))
+	for _, typ := range def.Types {
+		typDef := schema.Types[typ]
+		if typDef == nil {
+			return gqlerror.ErrorPosf(def.Position, "Undefined type %s.", strconv.Quote(typ))
 		}
-		if intDef.Kind != Interface {
-			return gqlerror.ErrorPosf(def.Position, "%s is a non interface type %s.", strconv.Quote(intf), intDef.Kind)
+		if !isValidKind(typDef.Kind, Object) {
+			return gqlerror.ErrorPosf(def.Position, "%s type %s must be %s.", def.Kind, strconv.Quote(typ), kindList(Object))
+		}
+	}
+
+	for _, intf := range def.Interfaces {
+		if err := validateImplements(schema, def, intf); err != nil {
+			return err
 		}
 	}
 
@@ -199,6 +205,13 @@ func validateDefinition(schema *Schema, def *Definition) *gqlerror.Error {
 		if len(def.Fields) == 0 {
 			return gqlerror.ErrorPosf(def.Position, "%s must define one or more fields.", def.Kind)
 		}
+		for _, field := range def.Fields {
+			if typ, ok := schema.Types[field.Type.Name()]; ok {
+				if !isValidKind(typ.Kind, Scalar, Object, Interface, Union, Enum) {
+					return gqlerror.ErrorPosf(field.Position, "%s field must be one of %s.", def.Kind, kindList(Scalar, Object, Interface, Union, Enum))
+				}
+			}
+		}
 	case Enum:
 		if len(def.EnumValues) == 0 {
 			return gqlerror.ErrorPosf(def.Position, "%s must define one or more unique enum values.", def.Kind)
@@ -207,6 +220,13 @@ func validateDefinition(schema *Schema, def *Definition) *gqlerror.Error {
 		if len(def.Fields) == 0 {
 			return gqlerror.ErrorPosf(def.Position, "%s must define one or more input fields.", def.Kind)
 		}
+		for _, field := range def.Fields {
+			if typ, ok := schema.Types[field.Type.Name()]; ok {
+				if !isValidKind(typ.Kind, Scalar, Enum, InputObject) {
+					return gqlerror.ErrorPosf(field.Position, "%s field must be one of %s.", def.Kind, kindList(Scalar, Enum, InputObject))
+				}
+			}
+		}
 	}
 
 	for idx, field1 := range def.Fields {
@@ -244,6 +264,16 @@ func validateArgs(schema *Schema, args ArgumentDefinitionList, currentDirective
 		if err := validateTypeRef(schema, arg.Type); err != nil {
 			return err
 		}
+		def := schema.Types[arg.Type.Name()]
+		if !def.IsInputType() {
+			return gqlerror.ErrorPosf(
+				arg.Position,
+				"cannot use %s as argument %s because %s is not a valid input type",
+				arg.Type.String(),
+				arg.Name,
+				def.Kind,
+			)
+		}
 		if err := validateDirectives(schema, arg.Directives, currentDirective); err != nil {
 			return err
 		}
@@ -268,9 +298,104 @@ func validateDirectives(schema *Schema, dirs DirectiveList, currentDirective *Di
 	return nil
 }
 
+func validateImplements(schema *Schema, def *Definition, intfName string) *gqlerror.Error {
+	// see validation rules at the bottom of
+	// https://facebook.github.io/graphql/June2018/#sec-Objects
+	intf := schema.Types[intfName]
+	if intf == nil {
+		return gqlerror.ErrorPosf(def.Position, "Undefined type %s.", strconv.Quote(intfName))
+	}
+	if intf.Kind != Interface {
+		return gqlerror.ErrorPosf(def.Position, "%s is a non interface type %s.", strconv.Quote(intfName), intf.Kind)
+	}
+	for _, requiredField := range intf.Fields {
+		foundField := def.Fields.ForName(requiredField.Name)
+		if foundField == nil {
+			return gqlerror.ErrorPosf(def.Position,
+				`For %s to implement %s it must have a field called %s.`,
+				def.Name, intf.Name, requiredField.Name,
+			)
+		}
+
+		if !isCovariant(schema, requiredField.Type, foundField.Type) {
+			return gqlerror.ErrorPosf(foundField.Position,
+				`For %s to implement %s the field %s must have type %s.`,
+				def.Name, intf.Name, requiredField.Name, requiredField.Type.String(),
+			)
+		}
+
+		for _, requiredArg := range requiredField.Arguments {
+			foundArg := foundField.Arguments.ForName(requiredArg.Name)
+			if foundArg == nil {
+				return gqlerror.ErrorPosf(foundField.Position,
+					`For %s to implement %s the field %s must have the same arguments but it is missing %s.`,
+					def.Name, intf.Name, requiredField.Name, requiredArg.Name,
+				)
+			}
+
+			if !requiredArg.Type.IsCompatible(foundArg.Type) {
+				return gqlerror.ErrorPosf(foundArg.Position,
+					`For %s to implement %s the field %s must have the same arguments but %s has the wrong type.`,
+					def.Name, intf.Name, requiredField.Name, requiredArg.Name,
+				)
+			}
+		}
+		for _, foundArgs := range foundField.Arguments {
+			if requiredField.Arguments.ForName(foundArgs.Name) == nil && foundArgs.Type.NonNull && foundArgs.DefaultValue == nil {
+				return gqlerror.ErrorPosf(foundArgs.Position,
+					`For %s to implement %s any additional arguments on %s must be optional or have a default value but %s is required.`,
+					def.Name, intf.Name, foundField.Name, foundArgs.Name,
+				)
+			}
+		}
+	}
+	return nil
+}
+
+func isCovariant(schema *Schema, required *Type, actual *Type) bool {
+	if required.NonNull && !actual.NonNull {
+		return false
+	}
+
+	if required.NamedType != "" {
+		if required.NamedType == actual.NamedType {
+			return true
+		}
+		for _, pt := range schema.PossibleTypes[required.NamedType] {
+			if pt.Name == actual.NamedType {
+				return true
+			}
+		}
+		return false
+	}
+
+	if required.Elem != nil && actual.Elem == nil {
+		return false
+	}
+
+	return isCovariant(schema, required.Elem, actual.Elem)
+}
+
 func validateName(pos *Position, name string) *gqlerror.Error {
 	if strings.HasPrefix(name, "__") {
 		return gqlerror.ErrorPosf(pos, `Name "%s" must not begin with "__", which is reserved by GraphQL introspection.`, name)
 	}
 	return nil
 }
+
+func isValidKind(kind DefinitionKind, valid ...DefinitionKind) bool {
+	for _, k := range valid {
+		if kind == k {
+			return true
+		}
+	}
+	return false
+}
+
+func kindList(kinds ...DefinitionKind) string {
+	s := make([]string, len(kinds))
+	for i, k := range kinds {
+		s[i] = string(k)
+	}
+	return strings.Join(s, ", ")
+}

vendor/github.com/vektah/gqlparser/validator/schema_test.yml

@@ -89,6 +89,18 @@ object types:
       message: 'Name "__bar" must not begin with "__", which is reserved by GraphQL introspection.'
       locations: [{line: 2, column: 7}]
 
+  - name: must not allow input object as field type 
+    input: |
+      input Input {
+        id: ID
+      }
+      type Query {
+        input: Input!
+      }
+    error:
+      message: 'OBJECT field must be one of SCALAR, OBJECT, INTERFACE, UNION, ENUM.'
+      locations: [{line: 5, column: 3}]
+
 interfaces:
   - name: must exist
     input: |
@@ -148,6 +160,121 @@ interfaces:
       message: 'Name "__FooBar" must not begin with "__", which is reserved by GraphQL introspection.'
       locations: [{line: 1, column: 11}]
 
+  - name: must not allow input object as field type 
+    input: |
+      input Input {
+        id: ID
+      }
+      type Query {
+        foo: Foo!
+      }
+      interface Foo {
+        input: Input!
+      }
+    error:
+      message: 'INTERFACE field must be one of SCALAR, OBJECT, INTERFACE, UNION, ENUM.'
+      locations: [{line: 8, column: 3}]
+
+  - name: must have all fields from interface
+    input: |
+      type Bar implements BarInterface {
+          someField: Int!
+      }
+
+      interface BarInterface {
+          id: ID!
+      }
+    error:
+      message: 'For Bar to implement BarInterface it must have a field called id.'
+      locations: [{line: 1, column: 6}]
+
+  - name: must have same type of fields
+    input: |
+      type Bar implements BarInterface {
+          id: Int!
+      }
+
+      interface BarInterface {
+          id: ID!
+      }
+    error:
+      message: 'For Bar to implement BarInterface the field id must have type ID!.'
+      locations: [{line: 2, column: 5}]
+
+  - name: must have all required arguments
+    input: |
+      type Bar implements BarInterface {
+          id: ID!
+      }
+
+      interface BarInterface {
+          id(ff: Int!): ID!
+      }
+    error:
+      message: 'For Bar to implement BarInterface the field id must have the same arguments but it is missing ff.'
+      locations: [{line: 2, column: 5}]
+
+  - name: must have same argument types
+    input: |
+      type Bar implements BarInterface {
+          id(ff: ID!): ID!
+      }
+
+      interface BarInterface {
+          id(ff: Int!): ID!
+      }
+    error:
+      message: 'For Bar to implement BarInterface the field id must have the same arguments but ff has the wrong type.'
+      locations: [{line: 2, column: 8}]
+
+  - name: may defined additional nullable arguments
+    input: |
+      type Bar implements BarInterface {
+          id(opt: Int): ID!
+      }
+
+      interface BarInterface {
+          id: ID!
+      }
+
+  - name: may defined additional required arguments with defaults
+    input: |
+      type Bar implements BarInterface {
+          id(opt: Int! = 1): ID!
+      }
+
+      interface BarInterface {
+          id: ID!
+      }
+
+  - name: must not define additional required arguments without defaults
+    input: |
+      type Bar implements BarInterface {
+          id(opt: Int!): ID!
+      }
+
+      interface BarInterface {
+          id: ID!
+      }
+    error:
+      message: 'For Bar to implement BarInterface any additional arguments on id must be optional or have a default value but opt is required.'
+      locations: [{line: 2, column: 8}]
+
+  - name: can have covariant argument types
+    input: |
+      union U = A|B
+
+      type A { name: String }
+      type B { name: String }
+
+      type Bar implements BarInterface {
+          f: A!
+      }
+
+      interface BarInterface {
+          f: U!
+      }
+
 inputs:
   - name: must define one or more input fields
     input: |
@@ -177,6 +304,70 @@ inputs:
       message: 'Name "__FooBar" must not begin with "__", which is reserved by GraphQL introspection.'
       locations: [{line: 1, column: 7}]
 
+  - name: fields cannot be Objects
+    input: |
+      type Object { id: ID }
+      input Foo { a: Object! }
+    error:
+      message: INPUT_OBJECT field must be one of SCALAR, ENUM, INPUT_OBJECT.
+      locations: [{line: 2, column: 13}]
+
+  - name: fields cannot be Interfaces
+    input: |
+      interface Interface { id: ID! }
+      input Foo { a: Interface! }
+    error:
+      message: INPUT_OBJECT field must be one of SCALAR, ENUM, INPUT_OBJECT.
+      locations: [{line: 2, column: 13}]
+
+  - name: fields cannot be Unions
+    input: |
+      type Object { id: ID }
+      union Union = Object
+      input Foo { a: Union! }
+    error:
+      message: INPUT_OBJECT field must be one of SCALAR, ENUM, INPUT_OBJECT.
+      locations: [{line: 3, column: 13}]
+
+args:
+  - name: Valid arg types
+    input: |
+        input Input { id: ID }
+        enum Enum { A }
+        scalar Scalar
+
+        type Query {
+          f(a: Input, b: Scalar, c: Enum): Boolean!
+        }
+
+  - name: Objects not allowed
+    input: |
+      type Object { id: ID }
+      type Query { f(a: Object): Boolean! }
+
+    error:
+      message: 'cannot use Object as argument a because OBJECT is not a valid input type'
+      locations: [{line: 2, column: 16}]
+
+  - name: Union not allowed
+    input: |
+      type Object { id: ID }
+      union Union = Object
+      type Query { f(a: Union): Boolean! }
+
+    error:
+      message: 'cannot use Union as argument a because UNION is not a valid input type'
+      locations: [{line: 3, column: 16}]
+
+  - name: Interface not allowed
+    input: |
+      interface Interface { id: ID }
+      type Query { f(a: Interface): Boolean! }
+
+    error:
+      message: 'cannot use Interface as argument a because INTERFACE is not a valid input type'
+      locations: [{line: 2, column: 16}]
+
 enums:
   - name: must define one or more unique enum values
     input: |
@@ -207,6 +398,26 @@ enums:
       message: 'Name "__FooBar" must not begin with "__", which is reserved by GraphQL introspection.'
       locations: [{line: 1, column: 6}]
 
+unions:
+  - name: union types must be defined
+    input: |
+      union Foo = Bar | Baz
+      type Bar {
+        id: ID
+      }
+    error:
+      message: "Undefined type \"Baz\"."
+      locations: [{line: 1, column: 7}]
+  - name: union types must be objects
+    input: |
+      union Foo = Baz
+      interface Baz {
+        id: ID
+      }
+    error:
+      message: "UNION type \"Baz\" must be OBJECT."
+      locations: [{line: 1, column: 7}]
+
 type extensions:
   - name: cannot extend non existant types
     input: |
@@ -258,6 +469,42 @@ directives:
       message: 'Name "__A" must not begin with "__", which is reserved by GraphQL introspection.'
       locations: [{line: 1, column: 12}]
 
+  - name: Valid arg types
+    input: |
+      input Input { id: ID }
+      enum Enum { A }
+      scalar Scalar
+
+      directive @A(a: Input, b: Scalar, c: Enum) on FIELD_DEFINITION
+
+  - name: Objects not allowed
+    input: |
+      type Object { id: ID }
+      directive @A(a: Object) on FIELD_DEFINITION
+
+    error:
+      message: 'cannot use Object as argument a because OBJECT is not a valid input type'
+      locations: [{line: 2, column: 14}]
+
+  - name: Union not allowed
+    input: |
+      type Object { id: ID }
+      union Union = Object
+      directive @A(a: Union) on FIELD_DEFINITION
+
+    error:
+      message: 'cannot use Union as argument a because UNION is not a valid input type'
+      locations: [{line: 3, column: 14}]
+
+  - name: Interface not allowed
+    input: |
+      interface Interface { id: ID }
+      directive @A(a: Interface) on FIELD_DEFINITION
+
+    error:
+      message: 'cannot use Interface as argument a because INTERFACE is not a valid input type'
+      locations: [{line: 2, column: 14}]
+
 entry points:
   - name: multiple schema entry points
     input: |