fix: implement offline scope in the way google expects

selfservice/strategy/oidc/provider_google.go

@@ -3,6 +3,15 @@
 
 package oidc
 
+import (
+	"context"
+
+	gooidc "github.com/coreos/go-oidc"
+	"golang.org/x/oauth2"
+
+	"github.com/ory/x/stringslice"
+)
+
 type ProviderGoogle struct {
 	*ProviderGenericOIDC
 }
@@ -19,3 +28,41 @@ func NewProviderGoogle(
 		},
 	}
 }
+
+func (g *ProviderGoogle) oauth2ConfigFromEndpoint(ctx context.Context, endpoint oauth2.Endpoint) *oauth2.Config {
+	scope := g.config.Scope
+	if !stringslice.Has(scope, gooidc.ScopeOpenID) {
+		scope = append(scope, gooidc.ScopeOpenID)
+	}
+
+	scope = stringslice.Filter(scope, func(s string) bool { return s == gooidc.ScopeOfflineAccess })
+
+	return &oauth2.Config{
+		ClientID:     g.config.ClientID,
+		ClientSecret: g.config.ClientSecret,
+		Endpoint:     endpoint,
+		Scopes:       scope,
+		RedirectURL:  g.config.Redir(g.reg.Config().OIDCRedirectURIBase(ctx)),
+	}
+}
+
+func (g *ProviderGoogle) OAuth2(ctx context.Context) (*oauth2.Config, error) {
+	p, err := g.provider(ctx)
+	if err != nil {
+		return nil, err
+	}
+
+	endpoint := p.Endpoint()
+	return g.oauth2ConfigFromEndpoint(ctx, endpoint), nil
+}
+
+func (g *ProviderGoogle) AuthCodeURLOptions(r ider) []oauth2.AuthCodeOption {
+	scope := g.config.Scope
+	options := g.ProviderGenericOIDC.AuthCodeURLOptions(r)
+
+	if stringslice.Has(scope, gooidc.ScopeOfflineAccess) {
+		options = append(options, oauth2.AccessTypeOffline)
+	}
+
+	return options
+}

selfservice/strategy/oidc/provider_google_test.go

@@ -0,0 +1,55 @@
+// Copyright © 2023 Ory Corp
+// SPDX-License-Identifier: Apache-2.0
+
+package oidc_test
+
+import (
+	"context"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"golang.org/x/oauth2"
+
+	"github.com/ory/kratos/internal"
+	"github.com/ory/kratos/selfservice/flow/login"
+	"github.com/ory/kratos/selfservice/strategy/oidc"
+	"github.com/ory/kratos/x"
+)
+
+func TestProviderGoogle_Scope(t *testing.T) {
+	_, reg := internal.NewFastRegistryWithMocks(t)
+
+	p := oidc.NewProviderGoogle(&oidc.Configuration{
+		Provider:        "google",
+		ID:              "valid",
+		ClientID:        "client",
+		ClientSecret:    "secret",
+		Mapper:          "file://./stub/hydra.schema.json",
+		RequestedClaims: nil,
+		Scope:           []string{"email", "profile", "offline_access"},
+	}, reg)
+
+	c, _ := p.OAuth2(context.Background())
+	assert.NotContains(t, c.Scopes, "offline_access")
+}
+
+func TestProviderGoogle_AccessType(t *testing.T) {
+	_, reg := internal.NewFastRegistryWithMocks(t)
+
+	p := oidc.NewProviderGoogle(&oidc.Configuration{
+		Provider:        "google",
+		ID:              "valid",
+		ClientID:        "client",
+		ClientSecret:    "secret",
+		Mapper:          "file://./stub/hydra.schema.json",
+		RequestedClaims: nil,
+		Scope:           []string{"email", "profile", "offline_access"},
+	}, reg)
+
+	r := &login.Flow{
+		ID: x.NewUUID(),
+	}
+
+	options := p.AuthCodeURLOptions(r)
+	assert.Contains(t, options, oauth2.AccessTypeOffline)
+}