entgql: support for edge schema with one field ID (#347)

* entgql: support for edge schema with one field ID

* entgql: update example schema for ID field

* entgql: run go generate

* entgql: remove edge fields and edges from WhereInput

* entgql: run go generate

* entgql: remove edge field from EdgeSchema node

* entgql: run go generate

* entgql: update tests

* entgql: keep edge fields for node

* entgql: run go generate

* entgql: enable the mutations on User for EdgeSchema

* entgql: skip EdgeSchema edge from mutations

* entgql: run go generate

* entgql: update schema tests

entgql/internal/todo/ent.graphql

@@ -132,10 +132,54 @@ input CreateTodoInput {
   secretID: ID
 }
 """
+CreateUserInput is used for create User object.
+Input was generated by ent.
+"""
+input CreateUserInput {
+  name: String
+  groupIDs: [ID!]
+  friendIDs: [ID!]
+}
+"""
 Define a Relay Cursor type:
 https://relay.dev/graphql/connections.htm#sec-Cursor
 """
 scalar Cursor
+type Friendship implements Node {
+  id: ID!
+  createdAt: Time!
+  userID: ID!
+  friendID: ID!
+  user: User!
+  friend: User!
+}
+"""
+FriendshipWhereInput is used for filtering Friendship objects.
+Input was generated by ent.
+"""
+input FriendshipWhereInput {
+  not: FriendshipWhereInput
+  and: [FriendshipWhereInput!]
+  or: [FriendshipWhereInput!]
+  """id field predicates"""
+  id: ID
+  idNEQ: ID
+  idIn: [ID!]
+  idNotIn: [ID!]
+  idGT: ID
+  idGTE: ID
+  idLT: ID
+  idLTE: ID
+  """created_at field predicates"""
+  createdAt: Time
+  createdAtNEQ: Time
+  createdAtIn: [Time!]
+  createdAtNotIn: [Time!]
+  createdAtGT: Time
+  createdAtGTE: Time
+  createdAtLT: Time
+  createdAtLTE: Time
+}
 type Group implements Node {
   id: ID!
   name: String!
@@ -434,6 +478,17 @@ input TodoWhereInput {
   hasCategory: Boolean
   hasCategoryWith: [CategoryWhereInput!]
 }
+"""
+UpdateUserInput is used for update User object.
+Input was generated by ent.
+"""
+input UpdateUserInput {
+  name: String
+  addGroupIDs: [ID!]
+  removeGroupIDs: [ID!]
+  addFriendIDs: [ID!]
+  removeFriendIDs: [ID!]
+}
 type User implements Node {
   id: ID!
   name: String!
@@ -454,6 +509,7 @@ type User implements Node {
     where: GroupWhereInput
   ): GroupConnection!
   friends: [User!]
+  friendships: [Friendship!]
 }
 """A connection to a list of items."""
 type UserConnection {
@@ -508,4 +564,7 @@ input UserWhereInput {
   """friends edge predicates"""
   hasFriends: Boolean
   hasFriendsWith: [UserWhereInput!]
+  """friendships edge predicates"""
+  hasFriendships: Boolean
+  hasFriendshipsWith: [FriendshipWhereInput!]
 }