Add unit test for handling external types in federation

Author: matthewmcneely

graphql/schema/federation_auxiliary_test.go

@@ -0,0 +1,107 @@
+/*
+ * SPDX-FileCopyrightText: © 2017-2026 Istari Digital, Inc.
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+package schema
+
+import (
+	"strings"
+	"testing"
+
+	"github.com/stretchr/testify/require"
+)
+
+// TestApolloServiceQueryExcludesAuxiliaryTypes verifies that auxiliary types
+// are not generated for @extends types when apolloServiceQuery=true
+func TestApolloServiceQueryExcludesAuxiliaryTypes(t *testing.T) {
+	schema := `
+type Review {
+	id: ID!
+	rating: Int! @search
+	comment: String @search(by: [fulltext])
+}
+
+extend type User @key(fields: "userId") {
+	userId: ID! @external
+	reviews: [Review]
+}
+`
+
+	// Parse with apolloServiceQuery=true (simulating _service query)
+	handler, err := NewHandler(schema, true)
+	require.NoError(t, err)
+
+	// Get the SDL that would be returned by _service
+	sdl := handler.GQLSchemaWithoutApolloExtras()
+
+	// These auxiliary types should NOT be present for extended User type
+	auxiliaryTypes := []string{
+		"input UserPatch",
+		"input AddUserInput",
+		"enum UserOrderable",
+		"enum UserHasFilter",
+		"input UserFilter",
+		"input UserRef",
+		"type AddUserPayload",
+		"type UpdateUserPayload",
+		"type DeleteUserPayload",
+		"addUser(",
+		"updateUser(",
+		"deleteUser(",
+		"getUser(",
+		"queryUser(",
+	}
+
+	for _, auxType := range auxiliaryTypes {
+		if strings.Contains(sdl, auxType) {
+			t.Errorf("SDL should NOT contain '%s' for extended User type", auxType)
+		}
+	}
+
+	// Review types SHOULD be present (not extended)
+	reviewTypes := []string{
+		"input ReviewPatch",
+		"input AddReviewInput",
+		"enum ReviewOrderable",
+		"enum ReviewHasFilter",
+	}
+
+	for _, reviewType := range reviewTypes {
+		if !strings.Contains(sdl, reviewType) {
+			t.Errorf("SDL SHOULD contain '%s' for Review type", reviewType)
+		}
+	}
+}
+
+// TestApolloServiceQueryWithoutExtends verifies that auxiliary types ARE generated
+// for regular types when apolloServiceQuery=true
+func TestApolloServiceQueryWithoutExtends(t *testing.T) {
+	schema := `
+type User @key(fields: "userId") {
+	userId: ID!
+	username: String! @search(by: [hash])
+	email: String
+}
+`
+
+	// Parse with apolloServiceQuery=true
+	handler, err := NewHandler(schema, true)
+	require.NoError(t, err)
+
+	sdl := handler.GQLSchemaWithoutApolloExtras()
+
+	// Auxiliary types SHOULD be present for non-extended User type
+	auxiliaryTypes := []string{
+		"input UserPatch",
+		"input AddUserInput",
+		"enum UserOrderable",
+		"enum UserHasFilter",
+	}
+
+	for _, auxType := range auxiliaryTypes {
+		if !strings.Contains(sdl, auxType) {
+			t.Errorf("SDL SHOULD contain '%s' for regular User type", auxType)
+		}
+	}
+}