From 4036f86fefbdd852a30df731e82e5e252b6cc8cb Mon Sep 17 00:00:00 2001
From: Dmitry Frolov <dmitry.frolov@gmail.com>
Date: Sun, 29 Dec 2024 12:39:21 +0700
Subject: [PATCH] fix: implement transitive interface output

Just copied relevant part from EnterObjectTypeDefinition()

Also add tests

Fixes #1018
---
 pkg/astprinter/astprinter.go         | 15 +++++++++++++++
 pkg/astprinter/astprinter_test.go    |  4 ++++
 v2/pkg/astprinter/astprinter.go      | 15 +++++++++++++++
 v2/pkg/astprinter/astprinter_test.go |  4 ++++
 4 files changed, 38 insertions(+)

diff --git a/pkg/astprinter/astprinter.go b/pkg/astprinter/astprinter.go
index 2e4e619cd..3ad4fa598 100644
--- a/pkg/astprinter/astprinter.go
+++ b/pkg/astprinter/astprinter.go
@@ -538,6 +538,21 @@ func (p *printVisitor) EnterInterfaceTypeDefinition(ref int) {
 	p.write(p.document.InterfaceTypeDefinitionNameBytes(ref))
 	p.write(literal.SPACE)
 
+	if len(p.document.InterfaceTypeDefinitions[ref].ImplementsInterfaces.Refs) != 0 {
+		p.write(literal.IMPLEMENTS)
+		p.write(literal.SPACE)
+		for i, j := range p.document.InterfaceTypeDefinitions[ref].ImplementsInterfaces.Refs {
+			if i != 0 {
+				p.write(literal.SPACE)
+				p.write(literal.AND)
+				p.write(literal.SPACE)
+			}
+			p.must(p.document.PrintType(j, p.out))
+		}
+		p.write(literal.SPACE)
+	}
+
+
 	p.inputValueDefinitionOpener = literal.LPAREN
 	p.inputValueDefinitionCloser = literal.RPAREN
 }
diff --git a/pkg/astprinter/astprinter_test.go b/pkg/astprinter/astprinter_test.go
index e50d5556f..b546dcffe 100644
--- a/pkg/astprinter/astprinter_test.go
+++ b/pkg/astprinter/astprinter_test.go
@@ -485,6 +485,10 @@ vary: [String]! = []) on QUERY directive @include(if: Boolean!) repeatable on FI
 				`scalar Date schema {query: Query} type Query {me: User! user(id: ID!): User allUsers: [User] search(term: String!): [SearchResult!]! myChats: [Chat!]!} enum Role {USER ADMIN} interface Node {id: ID!} union SearchResult = User | Chat | ChatMessage type User implements Node {id: ID! username: String! email: String! role: Role!} type Chat implements Node {id: ID! users: [User!]! messages: [ChatMessage!]!} type ChatMessage implements Node {id: ID! content: String! time: Date! user: User!}`)
 		})
 	})
+	t.Run("transitive interfaces", func(t *testing.T) {
+		run(t, "interface I1 {id: ID} interface I2 implements I1 {id: ID} interface I3 implements I1 & I2 {id: ID}",
+			"interface I1 {id: ID} interface I2 implements I1 {id: ID} interface I3 implements I1 & I2 {id: ID}")
+	})
 }
 
 func TestPrintArgumentWithBeforeAfterValue(t *testing.T) {
diff --git a/v2/pkg/astprinter/astprinter.go b/v2/pkg/astprinter/astprinter.go
index cd492dc25..6f45216af 100644
--- a/v2/pkg/astprinter/astprinter.go
+++ b/v2/pkg/astprinter/astprinter.go
@@ -601,6 +601,21 @@ func (p *printVisitor) EnterInterfaceTypeDefinition(ref int) {
 	p.write(p.document.InterfaceTypeDefinitionNameBytes(ref))
 	p.write(literal.SPACE)
 
+	if len(p.document.InterfaceTypeDefinitions[ref].ImplementsInterfaces.Refs) != 0 {
+		p.write(literal.IMPLEMENTS)
+		p.write(literal.SPACE)
+		for i, j := range p.document.InterfaceTypeDefinitions[ref].ImplementsInterfaces.Refs {
+			if i != 0 {
+				p.write(literal.SPACE)
+				p.write(literal.AND)
+				p.write(literal.SPACE)
+			}
+			p.must(p.document.PrintType(j, p.out))
+		}
+		p.write(literal.SPACE)
+	}
+
+
 	p.inputValueDefinitionOpener = literal.LPAREN
 	p.inputValueDefinitionCloser = literal.RPAREN
 }
diff --git a/v2/pkg/astprinter/astprinter_test.go b/v2/pkg/astprinter/astprinter_test.go
index 41f38c676..5f8b9bacd 100644
--- a/v2/pkg/astprinter/astprinter_test.go
+++ b/v2/pkg/astprinter/astprinter_test.go
@@ -654,6 +654,10 @@ fragment NameFragment on Dog {
 				`scalar Date schema {query: Query} type Query {me: User! user(id: ID!): User allUsers: [User] search(term: String!): [SearchResult!]! myChats: [Chat!]!} enum Role {USER ADMIN} interface Node {id: ID!} union SearchResult = User | Chat | ChatMessage type User implements Node {id: ID! username: String! email: String! role: Role!} type Chat implements Node {id: ID! users: [User!]! messages: [ChatMessage!]!} type ChatMessage implements Node {id: ID! content: String! time: Date! user: User!}`)
 		})
 	})
+	t.Run("transitive interfaces", func(t *testing.T) {
+		run(t, "interface I1 {id: ID} interface I2 implements I1 {id: ID} interface I3 implements I1 & I2 {id: ID}",
+			"interface I1 {id: ID} interface I2 implements I1 {id: ID} interface I3 implements I1 & I2 {id: ID}")
+	})
 }
 
 func TestPrintArgumentWithBeforeAfterValue(t *testing.T) {