From 24c3d2fe908ba606fe17f575bc33c05a2e4beff6 Mon Sep 17 00:00:00 2001 From: Ivan Goncharov Date: Fri, 3 Feb 2017 22:56:34 +0200 Subject: [PATCH] Forbid to implement same same interface twice --- spec/Section 3 -- Type System.md | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/spec/Section 3 -- Type System.md b/spec/Section 3 -- Type System.md index 644b0463b..e36b97c34 100644 --- a/spec/Section 3 -- Type System.md +++ b/spec/Section 3 -- Type System.md @@ -539,7 +539,8 @@ of rules must be adhered to by every Object type in a GraphQL schema. no two fields may share the same name. 3. Each field of an Object type must not have a name which begins with the characters {"__"} (two underscores). -4. An object type must be a super-set of all interfaces it implements: +4. An object type may declare that it implements one or more unique interfaces. +5. An object type must be a super-set of all interfaces it implements: 1. The object type must include a field of the same name for every field defined in an interface. 1. The object field must be of a type which is equal to or a sub-type of