[Bugfix]: Not validating queries with non-null params.

graphql.go

@@ -142,13 +142,12 @@ type Response struct {
 }
 
 // Validate validates the given query with the schema.
-func (s *Schema) Validate(queryString string) []*errors.QueryError {
+func (s *Schema) Validate(queryString string, variables map[string]interface{}) []*errors.QueryError {
 	doc, qErr := query.Parse(queryString)
 	if qErr != nil {
 		return []*errors.QueryError{qErr}
 	}
-
-	return validation.Validate(s.schema, doc, nil, s.maxDepth)
+	return validation.Validate(s.schema, doc, variables, s.maxDepth)
 }
 
 // Exec executes the given query with the schema's resolver. It panics if the schema was created
@@ -181,7 +180,7 @@ func (s *Schema) exec(ctx context.Context, queryString string, operationName str
 
 	// Subscriptions are not valid in Exec. Use schema.Subscribe() instead.
 	if op.Type == query.Subscription {
-		return &Response{Errors: []*errors.QueryError{&errors.QueryError{ Message: "graphql-ws protocol header is missing" }}}
+		return &Response{Errors: []*errors.QueryError{&errors.QueryError{Message: "graphql-ws protocol header is missing"}}}
 	}
 
 	// Fill in variables with the defaults from the operation