fix: schema definition included in schema-first approach

Author: burn2delete

packages/apollo/tests/generated-definitions/federation-partial-query.fixture.ts

@@ -12,4 +12,8 @@ export interface IQuery {
     foo(): Nullable<boolean> | Promise<Nullable<boolean>>;
 }
 
+export interface ISchema {
+    Query: IQuery;
+}
+
 type Nullable<T> = T | null;

packages/apollo/tests/generated-definitions/federation-typedef.fixture.ts

@@ -33,4 +33,8 @@ export class User {
     posts?: Nullable<Nullable<Post>[]>;
 }
 
+export class ISchema {
+    Query: IQuery;
+}
+
 type Nullable<T> = T | null;

packages/apollo/tests/generated-definitions/federation.fixture.ts

@@ -28,4 +28,8 @@ export class User {
     posts?: Nullable<Nullable<Post>[]>;
 }
 
+export class ISchema {
+    Query: IQuery;
+}
+
 type Nullable<T> = T | null;

packages/graphql/lib/federation/graphql-federation-definitions.factory.ts

@@ -41,7 +41,8 @@ export class GraphQLFederationDefinitionsFactory extends GraphQLDefinitionsFacto
     // This leads to duplicated IQuery interfaces
     // see: https://github.com//issues/2344
     const mergedDefinition = mergeTypeDefs([printSubgraphSchema(schema)], {
-      useSchemaDefinition: false,
+      // schema-first requires the schema definition to be included for federation 2 @link to function
+      useSchemaDefinition: true,
       throwOnConflict: true,
       commentDescriptions: true,
       reverseDirectives: true,