feat(federation): update Apollo Federation v2 definitions (#2635)

* feat(federation): update Apollo Federation v2 definitions

Fix Apollo Federation v2 directive definitions:
* `_FieldSet` was renamed `FieldSet`
* new `@composeDirective` (fed v2.1 change)
* `@shareable` is now repeatable (fed v2.2 change)
* new `@interfaceObject` directive (fed v2.3 change)

NOTE: definitions are updated to the latest Federation v2 spec. Users might specify old version import (i.e. `@link` import v2.0) trying to use new federation features (e.g. `@interfaceObject`) which may lead to potential composition errors (i.e. server starts up fine but cannot be federated into a "supergraph").

* regenerate examples

plugin/federation/federation.go

@@ -86,28 +86,55 @@ func (f *federation) MutateConfig(cfg *config.Config) error {
 }
 
 func (f *federation) InjectSourceEarly() *ast.Source {
-	input := `
-	scalar _Any
-	scalar _FieldSet
-	directive @requires(fields: _FieldSet!) on FIELD_DEFINITION
-	directive @provides(fields: _FieldSet!) on FIELD_DEFINITION
-	directive @extends on OBJECT | INTERFACE
-`
+	input := ``
+
 	// add version-specific changes on key directive, as well as adding the new directives for federation 2
 	if f.Version == 1 {
 		input += `
 	directive @key(fields: _FieldSet!) repeatable on OBJECT | INTERFACE
+	directive @requires(fields: _FieldSet!) on FIELD_DEFINITION
+	directive @provides(fields: _FieldSet!) on FIELD_DEFINITION
+	directive @extends on OBJECT | INTERFACE
 	directive @external on FIELD_DEFINITION
+	scalar _Any
+	scalar _FieldSet
 `
 	} else if f.Version == 2 {
 		input += `
-	directive @key(fields: _FieldSet!, resolvable: Boolean = true) repeatable on OBJECT | INTERFACE
-	directive @external on FIELD_DEFINITION | OBJECT
+	directive @composeDirective(name: String!) repeatable on SCHEMA
+	directive @extends on OBJECT | INTERFACE
+	directive @external on OBJECT | FIELD_DEFINITION
+	directive @key(fields: FieldSet!, resolvable: Boolean = true) repeatable on OBJECT | INTERFACE
+	directive @inaccessible on
+	  | ARGUMENT_DEFINITION
+	  | ENUM
+	  | ENUM_VALUE
+	  | FIELD_DEFINITION
+	  | INPUT_FIELD_DEFINITION
+	  | INPUT_OBJECT
+	  | INTERFACE
+	  | OBJECT
+	  | SCALAR
+	  | UNION
+	directive @interfaceObject on OBJECT
 	directive @link(import: [String!], url: String!) repeatable on SCHEMA
-	directive @shareable on OBJECT | FIELD_DEFINITION
-	directive @tag(name: String!) repeatable on FIELD_DEFINITION | INTERFACE | OBJECT | UNION | ARGUMENT_DEFINITION | SCALAR | ENUM | ENUM_VALUE | INPUT_OBJECT | INPUT_FIELD_DEFINITION
 	directive @override(from: String!) on FIELD_DEFINITION
-	directive @inaccessible on SCALAR | OBJECT | FIELD_DEFINITION | ARGUMENT_DEFINITION | INTERFACE | UNION | ENUM | ENUM_VALUE | INPUT_OBJECT | INPUT_FIELD_DEFINITION
+	directive @provides(fields: FieldSet!) on FIELD_DEFINITION
+	directive @requires(fields: FieldSet!) on FIELD_DEFINITION
+	directive @shareable repeatable on FIELD_DEFINITION | OBJECT
+	directive @tag(name: String!) repeatable on
+	  | ARGUMENT_DEFINITION
+	  | ENUM
+	  | ENUM_VALUE
+	  | FIELD_DEFINITION
+	  | INPUT_FIELD_DEFINITION
+	  | INPUT_OBJECT
+	  | INTERFACE
+	  | OBJECT
+	  | SCALAR
+	  | UNION
+	scalar _Any
+	scalar FieldSet
 `
 	}
 	return &ast.Source{

plugin/federation/test_data/model2/federation.go

@@ -0,0 +1,48 @@
+package model2
+
+type FieldSet string //nolint:deadcode,unused
+
+type Hello struct {
+	Name      string
+	Secondary string
+}
+
+func (Hello) IsEntity() {}
+
+type World struct {
+	Foo string
+	Bar int
+}
+
+func (World) IsEntity() {}
+
+type ExternalExtension struct {
+	UPC     string
+	Reviews []*World
+}
+
+func (ExternalExtension) IsEntity() {}
+
+type NestedKey struct {
+	ID    string
+	Hello *Hello
+}
+
+func (NestedKey) IsEntity() {}
+
+type MoreNesting struct {
+	ID    string
+	World *World
+}
+
+func (MoreNesting) IsEntity() {}
+
+type VeryNestedKey struct {
+	ID     string
+	Hello  *Hello
+	World  *World
+	Nested *NestedKey
+	More   *MoreNesting
+}
+
+func (VeryNestedKey) IsEntity() {}

plugin/federation/testdata/federation2/federation2.graphql

@@ -1,5 +1,5 @@
 extend schema
-  @link(url: "https://specs.apollo.dev/federation/v2.0",
+  @link(url: "https://specs.apollo.dev/federation/v2.3",
         import: ["@key", "@shareable", "@provides", "@external", "@tag", "@extends", "@override", "@inaccessible"])
 
 schema {

plugin/federation/testdata/federation2/federation2.yml

@@ -7,4 +7,4 @@ federation:
   version: 2
 
 autobind:
-  - "github.com/99designs/gqlgen/plugin/federation/test_data/model"
+  - "github.com/99designs/gqlgen/plugin/federation/test_data/model2"