From da163390f192c2f82963b563e3758dc3489e58f3 Mon Sep 17 00:00:00 2001
From: Qingyang Hu <qingyang.hu@mongodb.com>
Date: Wed, 16 Apr 2025 18:30:05 -0400
Subject: [PATCH 1/6] GODRIVER-3037 Support internal-only options.

---
 mongo/options/internaloptions.go      | 38 ++++++++++++++
 mongo/options/internaloptions_test.go | 73 +++++++++++++++++++++++++++
 2 files changed, 111 insertions(+)
 create mode 100644 mongo/options/internaloptions.go
 create mode 100644 mongo/options/internaloptions_test.go

diff --git a/mongo/options/internaloptions.go b/mongo/options/internaloptions.go
new file mode 100644
index 0000000000..cb58536699
--- /dev/null
+++ b/mongo/options/internaloptions.go
@@ -0,0 +1,38 @@
+// Copyright (C) MongoDB, Inc. 2025-present.
+//
+// Licensed under the Apache License, Version 2.0 (the "License"); you may
+// not use this file except in compliance with the License. You may obtain
+// a copy of the License at http://www.apache.org/licenses/LICENSE-2.0
+
+package options
+
+import (
+	"fmt"
+
+	"go.mongodb.org/mongo-driver/v2/x/mongo/driver"
+)
+
+// Deprecated: SetInternalClientOptions sets internal only options for ClientOptions. It may be changed
+// or removed in any release.
+func SetInternalClientOptions(opts *ClientOptions, custom map[string]any) (*ClientOptions, error) {
+	const typeErr = "unexpected type for %s"
+	for k, v := range custom {
+		switch k {
+		case "crypt":
+			c, ok := v.(driver.Crypt)
+			if !ok {
+				return nil, fmt.Errorf(typeErr, k)
+			}
+			opts.Crypt = c
+		case "deployment":
+			d, ok := v.(driver.Deployment)
+			if !ok {
+				return nil, fmt.Errorf(typeErr, k)
+			}
+			opts.Deployment = d
+		default:
+			return nil, fmt.Errorf("unsupported option: %s", k)
+		}
+	}
+	return opts, nil
+}
diff --git a/mongo/options/internaloptions_test.go b/mongo/options/internaloptions_test.go
new file mode 100644
index 0000000000..b0d23d0f46
--- /dev/null
+++ b/mongo/options/internaloptions_test.go
@@ -0,0 +1,73 @@
+// Copyright (C) MongoDB, Inc. 2025-present.
+//
+// Licensed under the Apache License, Version 2.0 (the "License"); you may
+// not use this file except in compliance with the License. You may obtain
+// a copy of the License at http://www.apache.org/licenses/LICENSE-2.0
+
+package options
+
+import (
+	"testing"
+
+	"go.mongodb.org/mongo-driver/v2/internal/require"
+	"go.mongodb.org/mongo-driver/v2/x/mongo/driver"
+	"go.mongodb.org/mongo-driver/v2/x/mongo/driver/drivertest"
+)
+
+func TestSetClientOptions(t *testing.T) {
+	t.Parallel()
+
+	t.Run("set Crypt with driver.Crypt", func(t *testing.T) {
+		t.Parallel()
+
+		opts := &ClientOptions{}
+		c := driver.NewCrypt(&driver.CryptOptions{})
+		opts, err := SetInternalClientOptions(opts, map[string]any{
+			"crypt": c,
+		})
+		require.NoError(t, err)
+		require.Equal(t, c, opts.Crypt)
+	})
+
+	t.Run("set Crypt with driver.Deployment", func(t *testing.T) {
+		t.Parallel()
+
+		opts := &ClientOptions{}
+		_, err := SetInternalClientOptions(opts, map[string]any{
+			"crypt": &drivertest.MockDeployment{},
+		})
+		require.EqualError(t, err, "unexpected type for crypt")
+	})
+
+	t.Run("set Deployment with driver.Deployment", func(t *testing.T) {
+		t.Parallel()
+
+		opts := &ClientOptions{}
+		d := &drivertest.MockDeployment{}
+		opts, err := SetInternalClientOptions(opts, map[string]any{
+			"deployment": d,
+		})
+		require.NoError(t, err)
+		require.Equal(t, d, opts.Deployment)
+	})
+
+	t.Run("set Deployment with driver.Crypt", func(t *testing.T) {
+		t.Parallel()
+
+		opts := &ClientOptions{}
+		_, err := SetInternalClientOptions(opts, map[string]any{
+			"deployment": driver.NewCrypt(&driver.CryptOptions{}),
+		})
+		require.EqualError(t, err, "unexpected type for deployment")
+	})
+
+	t.Run("set unsupported option", func(t *testing.T) {
+		t.Parallel()
+
+		opts := &ClientOptions{}
+		_, err := SetInternalClientOptions(opts, map[string]any{
+			"unsupported": "unsupported",
+		})
+		require.EqualError(t, err, "unsupported option: unsupported")
+	})
+}

From dbd783757d9b1c368089032fc6ff5928b293cd9f Mon Sep 17 00:00:00 2001
From: Qingyang Hu <qingyang.hu@mongodb.com>
Date: Wed, 16 Apr 2025 18:40:56 -0400
Subject: [PATCH 2/6] update comment

---
 mongo/options/internaloptions.go | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/mongo/options/internaloptions.go b/mongo/options/internaloptions.go
index cb58536699..d69f7e187f 100644
--- a/mongo/options/internaloptions.go
+++ b/mongo/options/internaloptions.go
@@ -12,8 +12,9 @@ import (
 	"go.mongodb.org/mongo-driver/v2/x/mongo/driver"
 )
 
-// Deprecated: SetInternalClientOptions sets internal only options for ClientOptions. It may be changed
-// or removed in any release.
+// SetInternalClientOptions sets internal options for ClientOptions.
+//
+// Deprecated: This function is for internal use only. It may be changed or removed in any release.
 func SetInternalClientOptions(opts *ClientOptions, custom map[string]any) (*ClientOptions, error) {
 	const typeErr = "unexpected type for %s"
 	for k, v := range custom {

From 81b9815d55f7972d1a26f81281e7d5595ff55418 Mon Sep 17 00:00:00 2001
From: Qingyang Hu <qingyang.hu@mongodb.com>
Date: Mon, 21 Apr 2025 17:06:04 -0400
Subject: [PATCH 3/6] GODRIVER-3429 Revert internal-only
 "AuthenticateToAnything".

---
 internal/options/options.go                 | 32 +++++++++
 mongo/options/clientoptions.go              |  7 ++
 mongo/options/internaloptions.go            | 39 -----------
 mongo/options/internaloptions_test.go       | 73 ---------------------
 x/mongo/driver/options/options.go           | 45 +++++++++++++
 x/mongo/driver/topology/topology_options.go | 10 +++
 6 files changed, 94 insertions(+), 112 deletions(-)
 create mode 100644 internal/options/options.go
 delete mode 100644 mongo/options/internaloptions.go
 delete mode 100644 mongo/options/internaloptions_test.go
 create mode 100644 x/mongo/driver/options/options.go

diff --git a/internal/options/options.go b/internal/options/options.go
new file mode 100644
index 0000000000..91308f5745
--- /dev/null
+++ b/internal/options/options.go
@@ -0,0 +1,32 @@
+// Copyright (C) MongoDB, Inc. 2025-present.
+//
+// Licensed under the Apache License, Version 2.0 (the "License"); you may
+// not use this file except in compliance with the License. You may obtain
+// a copy of the License at http://www.apache.org/licenses/LICENSE-2.0
+
+package options
+
+// Options stores internal options.
+type Options struct {
+	values map[string]any
+}
+
+// WithValue sets an option value with the associated key.
+func WithValue(opts Options, key string, option any) Options {
+	if opts.values == nil {
+		opts.values = make(map[string]any)
+	}
+	opts.values[key] = option
+	return opts
+}
+
+// Value returns the value associated with the options for key.
+func Value(opts Options, key string) any {
+	if opts.values == nil {
+		return nil
+	}
+	if val, ok := opts.values[key]; ok {
+		return val
+	}
+	return nil
+}
diff --git a/mongo/options/clientoptions.go b/mongo/options/clientoptions.go
index 925325c6c5..2aa94f8960 100644
--- a/mongo/options/clientoptions.go
+++ b/mongo/options/clientoptions.go
@@ -26,6 +26,7 @@ import (
 	"go.mongodb.org/mongo-driver/v2/bson"
 	"go.mongodb.org/mongo-driver/v2/event"
 	"go.mongodb.org/mongo-driver/v2/internal/httputil"
+	"go.mongodb.org/mongo-driver/v2/internal/options"
 	"go.mongodb.org/mongo-driver/v2/mongo/readconcern"
 	"go.mongodb.org/mongo-driver/v2/mongo/readpref"
 	"go.mongodb.org/mongo-driver/v2/mongo/writeconcern"
@@ -295,6 +296,12 @@ type ClientOptions struct {
 	// release.
 	Deployment driver.Deployment
 
+	// Custom specifies internal options for the new Client.
+	//
+	// Deprecated: This option is for internal use only and should not be set. It may be changed or removed in any
+	// release.
+	Custom options.Options
+
 	connString *connstring.ConnString
 	err        error
 }
diff --git a/mongo/options/internaloptions.go b/mongo/options/internaloptions.go
deleted file mode 100644
index d69f7e187f..0000000000
--- a/mongo/options/internaloptions.go
+++ /dev/null
@@ -1,39 +0,0 @@
-// Copyright (C) MongoDB, Inc. 2025-present.
-//
-// Licensed under the Apache License, Version 2.0 (the "License"); you may
-// not use this file except in compliance with the License. You may obtain
-// a copy of the License at http://www.apache.org/licenses/LICENSE-2.0
-
-package options
-
-import (
-	"fmt"
-
-	"go.mongodb.org/mongo-driver/v2/x/mongo/driver"
-)
-
-// SetInternalClientOptions sets internal options for ClientOptions.
-//
-// Deprecated: This function is for internal use only. It may be changed or removed in any release.
-func SetInternalClientOptions(opts *ClientOptions, custom map[string]any) (*ClientOptions, error) {
-	const typeErr = "unexpected type for %s"
-	for k, v := range custom {
-		switch k {
-		case "crypt":
-			c, ok := v.(driver.Crypt)
-			if !ok {
-				return nil, fmt.Errorf(typeErr, k)
-			}
-			opts.Crypt = c
-		case "deployment":
-			d, ok := v.(driver.Deployment)
-			if !ok {
-				return nil, fmt.Errorf(typeErr, k)
-			}
-			opts.Deployment = d
-		default:
-			return nil, fmt.Errorf("unsupported option: %s", k)
-		}
-	}
-	return opts, nil
-}
diff --git a/mongo/options/internaloptions_test.go b/mongo/options/internaloptions_test.go
deleted file mode 100644
index b0d23d0f46..0000000000
--- a/mongo/options/internaloptions_test.go
+++ /dev/null
@@ -1,73 +0,0 @@
-// Copyright (C) MongoDB, Inc. 2025-present.
-//
-// Licensed under the Apache License, Version 2.0 (the "License"); you may
-// not use this file except in compliance with the License. You may obtain
-// a copy of the License at http://www.apache.org/licenses/LICENSE-2.0
-
-package options
-
-import (
-	"testing"
-
-	"go.mongodb.org/mongo-driver/v2/internal/require"
-	"go.mongodb.org/mongo-driver/v2/x/mongo/driver"
-	"go.mongodb.org/mongo-driver/v2/x/mongo/driver/drivertest"
-)
-
-func TestSetClientOptions(t *testing.T) {
-	t.Parallel()
-
-	t.Run("set Crypt with driver.Crypt", func(t *testing.T) {
-		t.Parallel()
-
-		opts := &ClientOptions{}
-		c := driver.NewCrypt(&driver.CryptOptions{})
-		opts, err := SetInternalClientOptions(opts, map[string]any{
-			"crypt": c,
-		})
-		require.NoError(t, err)
-		require.Equal(t, c, opts.Crypt)
-	})
-
-	t.Run("set Crypt with driver.Deployment", func(t *testing.T) {
-		t.Parallel()
-
-		opts := &ClientOptions{}
-		_, err := SetInternalClientOptions(opts, map[string]any{
-			"crypt": &drivertest.MockDeployment{},
-		})
-		require.EqualError(t, err, "unexpected type for crypt")
-	})
-
-	t.Run("set Deployment with driver.Deployment", func(t *testing.T) {
-		t.Parallel()
-
-		opts := &ClientOptions{}
-		d := &drivertest.MockDeployment{}
-		opts, err := SetInternalClientOptions(opts, map[string]any{
-			"deployment": d,
-		})
-		require.NoError(t, err)
-		require.Equal(t, d, opts.Deployment)
-	})
-
-	t.Run("set Deployment with driver.Crypt", func(t *testing.T) {
-		t.Parallel()
-
-		opts := &ClientOptions{}
-		_, err := SetInternalClientOptions(opts, map[string]any{
-			"deployment": driver.NewCrypt(&driver.CryptOptions{}),
-		})
-		require.EqualError(t, err, "unexpected type for deployment")
-	})
-
-	t.Run("set unsupported option", func(t *testing.T) {
-		t.Parallel()
-
-		opts := &ClientOptions{}
-		_, err := SetInternalClientOptions(opts, map[string]any{
-			"unsupported": "unsupported",
-		})
-		require.EqualError(t, err, "unsupported option: unsupported")
-	})
-}
diff --git a/x/mongo/driver/options/options.go b/x/mongo/driver/options/options.go
new file mode 100644
index 0000000000..464085a903
--- /dev/null
+++ b/x/mongo/driver/options/options.go
@@ -0,0 +1,45 @@
+// Copyright (C) MongoDB, Inc. 2025-present.
+//
+// Licensed under the Apache License, Version 2.0 (the "License"); you may
+// not use this file except in compliance with the License. You may obtain
+// a copy of the License at http://www.apache.org/licenses/LICENSE-2.0
+
+package options
+
+import (
+	"fmt"
+
+	internalOptions "go.mongodb.org/mongo-driver/v2/internal/options"
+	"go.mongodb.org/mongo-driver/v2/mongo/options"
+	"go.mongodb.org/mongo-driver/v2/x/mongo/driver"
+)
+
+// SetInternalClientOptions sets internal options for ClientOptions.
+//
+// Deprecated: This function is for internal use only. It may be changed or removed in any release.
+func SetInternalClientOptions(opts *options.ClientOptions, key string, option any) error {
+	const typeErr = "unexpected type for %s"
+	switch key {
+	case "crypt":
+		c, ok := option.(driver.Crypt)
+		if !ok {
+			return fmt.Errorf(typeErr, key)
+		}
+		opts.Crypt = c
+	case "deployment":
+		d, ok := option.(driver.Deployment)
+		if !ok {
+			return fmt.Errorf(typeErr, key)
+		}
+		opts.Deployment = d
+	case "authenticateToAnything":
+		b, ok := option.(bool)
+		if !ok {
+			return fmt.Errorf(typeErr, key)
+		}
+		opts.Custom = internalOptions.WithValue(opts.Custom, key, b)
+	default:
+		return fmt.Errorf("unsupported option: %s", key)
+	}
+	return nil
+}
diff --git a/x/mongo/driver/topology/topology_options.go b/x/mongo/driver/topology/topology_options.go
index aefa74c56a..0f0138e566 100644
--- a/x/mongo/driver/topology/topology_options.go
+++ b/x/mongo/driver/topology/topology_options.go
@@ -15,9 +15,11 @@ import (
 
 	"go.mongodb.org/mongo-driver/v2/event"
 	"go.mongodb.org/mongo-driver/v2/internal/logger"
+	internalOptions "go.mongodb.org/mongo-driver/v2/internal/options"
 	"go.mongodb.org/mongo-driver/v2/mongo/options"
 	"go.mongodb.org/mongo-driver/v2/x/mongo/driver"
 	"go.mongodb.org/mongo-driver/v2/x/mongo/driver/auth"
+	"go.mongodb.org/mongo-driver/v2/x/mongo/driver/description"
 	"go.mongodb.org/mongo-driver/v2/x/mongo/driver/ocsp"
 	"go.mongodb.org/mongo-driver/v2/x/mongo/driver/operation"
 	"go.mongodb.org/mongo-driver/v2/x/mongo/driver/session"
@@ -270,6 +272,14 @@ func NewConfigFromOptionsWithAuthenticator(opts *options.ClientOptions, clock *s
 			// Required for SASL mechanism negotiation during handshake
 			handshakeOpts.DBUser = opts.Auth.AuthSource + "." + opts.Auth.Username
 		}
+		if a := internalOptions.Value(opts.Custom, "authenticateToAnything"); a != nil {
+			if v, ok := a.(bool); ok && v {
+				// Authenticate arbiters
+				handshakeOpts.PerformAuthentication = func(_ description.Server) bool {
+					return true
+				}
+			}
+		}
 
 		handshaker = func(driver.Handshaker) driver.Handshaker {
 			return auth.Handshaker(nil, handshakeOpts)

From 16f8f2852431c65df9bc03c2b6be4f482408516a Mon Sep 17 00:00:00 2001
From: Qingyang Hu <qingyang.hu@mongodb.com>
Date: Mon, 21 Apr 2025 18:11:10 -0400
Subject: [PATCH 4/6] fix test

---
 internal/options/options.go         | 13 +++++++++++++
 mongo/options/clientoptions_test.go |  3 +++
 2 files changed, 16 insertions(+)

diff --git a/internal/options/options.go b/internal/options/options.go
index 91308f5745..8d5f47f422 100644
--- a/internal/options/options.go
+++ b/internal/options/options.go
@@ -30,3 +30,16 @@ func Value(opts Options, key string) any {
 	}
 	return nil
 }
+
+// Equal compares two Options instances for equality.
+func Equal(opts1, opts2 Options) bool {
+	if len(opts1.values) != len(opts2.values) {
+		return false
+	}
+	for key, val1 := range opts1.values {
+		if val2, ok := opts2.values[key]; !ok || val1 != val2 {
+			return false
+		}
+	}
+	return true
+}
diff --git a/mongo/options/clientoptions_test.go b/mongo/options/clientoptions_test.go
index 907584d5f0..a8a00122e0 100644
--- a/mongo/options/clientoptions_test.go
+++ b/mongo/options/clientoptions_test.go
@@ -27,6 +27,7 @@ import (
 	"go.mongodb.org/mongo-driver/v2/event"
 	"go.mongodb.org/mongo-driver/v2/internal/assert"
 	"go.mongodb.org/mongo-driver/v2/internal/httputil"
+	"go.mongodb.org/mongo-driver/v2/internal/options"
 	"go.mongodb.org/mongo-driver/v2/internal/ptrutil"
 	"go.mongodb.org/mongo-driver/v2/mongo/readconcern"
 	"go.mongodb.org/mongo-driver/v2/mongo/readpref"
@@ -156,6 +157,7 @@ func TestClientOptions(t *testing.T) {
 				cmp.Comparer(func(r1, r2 *bson.Registry) bool { return r1 == r2 }),
 				cmp.Comparer(func(cfg1, cfg2 *tls.Config) bool { return cfg1 == cfg2 }),
 				cmp.Comparer(func(fp1, fp2 *event.PoolMonitor) bool { return fp1 == fp2 }),
+				cmp.Comparer(options.Equal),
 				cmp.AllowUnexported(ClientOptions{}),
 				cmpopts.IgnoreFields(http.Client{}, "Transport"),
 			); diff != "" {
@@ -1253,6 +1255,7 @@ func TestApplyURI(t *testing.T) {
 				cmp.Comparer(func(r1, r2 *bson.Registry) bool { return r1 == r2 }),
 				cmp.Comparer(compareTLSConfig),
 				cmp.Comparer(compareErrors),
+				cmp.Comparer(options.Equal),
 				cmpopts.SortSlices(stringLess),
 				cmpopts.IgnoreFields(connstring.ConnString{}, "SSLClientCertificateKeyPassword"),
 				cmpopts.IgnoreFields(http.Client{}, "Transport"),

From 66b8813b732966914a6551c04d36e1d7aa552f79 Mon Sep 17 00:00:00 2001
From: Qingyang Hu <qingyang.hu@mongodb.com>
Date: Thu, 24 Apr 2025 18:38:22 -0400
Subject: [PATCH 5/6] add tests

---
 x/mongo/driver/auth/auth_test.go              | 59 +++++++++++++++
 x/mongo/driver/options/options_test.go        | 64 ++++++++++++++++
 .../driver/topology/topology_options_test.go  | 73 +++++++++++++++++++
 3 files changed, 196 insertions(+)
 create mode 100644 x/mongo/driver/options/options_test.go

diff --git a/x/mongo/driver/auth/auth_test.go b/x/mongo/driver/auth/auth_test.go
index 4736144e59..27aa38741f 100644
--- a/x/mongo/driver/auth/auth_test.go
+++ b/x/mongo/driver/auth/auth_test.go
@@ -7,13 +7,19 @@
 package auth_test
 
 import (
+	"context"
+	"fmt"
 	"net/http"
 	"testing"
 
 	"github.com/google/go-cmp/cmp"
 	"go.mongodb.org/mongo-driver/v2/internal/require"
 	"go.mongodb.org/mongo-driver/v2/x/bsonx/bsoncore"
+	"go.mongodb.org/mongo-driver/v2/x/mongo/driver"
 	"go.mongodb.org/mongo-driver/v2/x/mongo/driver/auth"
+	"go.mongodb.org/mongo-driver/v2/x/mongo/driver/description"
+	"go.mongodb.org/mongo-driver/v2/x/mongo/driver/drivertest"
+	"go.mongodb.org/mongo-driver/v2/x/mongo/driver/mnet"
 	"go.mongodb.org/mongo-driver/v2/x/mongo/driver/wiremessage"
 )
 
@@ -101,3 +107,56 @@ func compareResponses(t *testing.T, wm []byte, expectedPayload bsoncore.Document
 		t.Errorf("Payloads don't match. got %v; want %v", actualPayload, expectedPayload)
 	}
 }
+
+type testAuthenticator struct{}
+
+func (a *testAuthenticator) Auth(context.Context, *driver.AuthConfig) error {
+	return fmt.Errorf("test error")
+}
+
+func (a *testAuthenticator) Reauth(context.Context, *driver.AuthConfig) error {
+	return nil
+}
+
+func TestPerformAuthentication(t *testing.T) {
+	t.Parallel()
+
+	cases := []struct {
+		name          string
+		needToPerform bool
+		assert        func(*testing.T, error)
+	}{
+		{
+			name:          "positive",
+			needToPerform: true,
+			assert: func(t *testing.T, err error) {
+				require.EqualError(t, err, "auth error: test error")
+			},
+		},
+		{
+			name:          "negative",
+			needToPerform: false,
+			assert: func(t *testing.T, err error) {
+				require.NoError(t, err)
+			},
+		},
+	}
+	mnetconn := mnet.NewConnection(&drivertest.ChannelConn{})
+	for _, tc := range cases {
+		tc := tc
+
+		t.Run(tc.name, func(t *testing.T) {
+			t.Parallel()
+
+			handshaker := auth.Handshaker(nil, &auth.HandshakeOptions{
+				Authenticator: &testAuthenticator{},
+				PerformAuthentication: func(description.Server) bool {
+					return tc.needToPerform
+				},
+			})
+
+			err := handshaker.FinishHandshake(context.Background(), mnetconn)
+			tc.assert(t, err)
+		})
+	}
+}
diff --git a/x/mongo/driver/options/options_test.go b/x/mongo/driver/options/options_test.go
new file mode 100644
index 0000000000..8c383e79ee
--- /dev/null
+++ b/x/mongo/driver/options/options_test.go
@@ -0,0 +1,64 @@
+// Copyright (C) MongoDB, Inc. 2025-present.
+//
+// Licensed under the Apache License, Version 2.0 (the "License"); you may
+// not use this file except in compliance with the License. You may obtain
+// a copy of the License at http://www.apache.org/licenses/LICENSE-2.0
+
+package options
+
+import (
+	"testing"
+
+	internalOptions "go.mongodb.org/mongo-driver/v2/internal/options"
+	"go.mongodb.org/mongo-driver/v2/internal/require"
+	"go.mongodb.org/mongo-driver/v2/mongo/options"
+	"go.mongodb.org/mongo-driver/v2/x/mongo/driver"
+	"go.mongodb.org/mongo-driver/v2/x/mongo/driver/drivertest"
+)
+
+func TestSetInternalClientOptions(t *testing.T) {
+	t.Parallel()
+
+	cases := []struct {
+		key   string
+		value any
+	}{
+		{
+			key:   "authenticateToAnything",
+			value: true,
+		},
+	}
+	for _, tc := range cases {
+		tc := tc
+
+		t.Run(tc.key, func(t *testing.T) {
+			t.Parallel()
+
+			opts := options.Client()
+			err := SetInternalClientOptions(opts, tc.key, tc.value)
+			require.NoError(t, err, "error setting %s: %v", tc.key, err)
+			v := internalOptions.Value(opts.Custom, tc.key)
+			require.Equal(t, tc.value, v, "expected %v, got %v", tc.value, v)
+		})
+	}
+
+	t.Run("crypt", func(t *testing.T) {
+		t.Parallel()
+
+		c := driver.NewCrypt(&driver.CryptOptions{})
+		opts := options.Client()
+		err := SetInternalClientOptions(opts, "crypt", c)
+		require.NoError(t, err, "error setting crypt: %v", err)
+		require.Equal(t, c, opts.Crypt, "expected %v, got %v", c, opts.Crypt)
+	})
+
+	t.Run("deployment", func(t *testing.T) {
+		t.Parallel()
+
+		d := &drivertest.MockDeployment{}
+		opts := options.Client()
+		err := SetInternalClientOptions(opts, "deployment", d)
+		require.NoError(t, err, "error setting deployment: %v", err)
+		require.Equal(t, d, opts.Deployment, "expected %v, got %v", d, opts.Deployment)
+	})
+}
diff --git a/x/mongo/driver/topology/topology_options_test.go b/x/mongo/driver/topology/topology_options_test.go
index 759ab9aa4a..4646721744 100644
--- a/x/mongo/driver/topology/topology_options_test.go
+++ b/x/mongo/driver/topology/topology_options_test.go
@@ -7,6 +7,7 @@
 package topology
 
 import (
+	"context"
 	"fmt"
 	"net/url"
 	"reflect"
@@ -17,6 +18,10 @@ import (
 	"go.mongodb.org/mongo-driver/v2/internal/require"
 	"go.mongodb.org/mongo-driver/v2/mongo/options"
 	"go.mongodb.org/mongo-driver/v2/x/mongo/driver"
+	"go.mongodb.org/mongo-driver/v2/x/mongo/driver/description"
+	"go.mongodb.org/mongo-driver/v2/x/mongo/driver/drivertest"
+	"go.mongodb.org/mongo-driver/v2/x/mongo/driver/mnet"
+	xoptions "go.mongodb.org/mongo-driver/v2/x/mongo/driver/options"
 )
 
 func TestDirectConnectionFromConnString(t *testing.T) {
@@ -85,6 +90,74 @@ func TestLoadBalancedFromConnString(t *testing.T) {
 	}
 }
 
+type testAuthenticator struct{}
+
+func (a *testAuthenticator) Auth(context.Context, *driver.AuthConfig) error {
+	return fmt.Errorf("test error")
+}
+
+func (a *testAuthenticator) Reauth(context.Context, *driver.AuthConfig) error {
+	return nil
+}
+
+func TestAuthenticateToAnything(t *testing.T) {
+	t.Parallel()
+
+	cases := []struct {
+		name   string
+		set    func(*options.ClientOptions) error
+		assert func(*testing.T, error)
+	}{
+		{
+			name: "default",
+			set:  func(*options.ClientOptions) error { return nil },
+			assert: func(t *testing.T, err error) {
+				require.NoError(t, err)
+			},
+		},
+		{
+			name: "positive",
+			set: func(opt *options.ClientOptions) error {
+				return xoptions.SetInternalClientOptions(opt, "authenticateToAnything", true)
+			},
+			assert: func(t *testing.T, err error) {
+				require.EqualError(t, err, "auth error: test error")
+			},
+		},
+		{
+			name: "negative",
+			set: func(opt *options.ClientOptions) error {
+				return xoptions.SetInternalClientOptions(opt, "authenticateToAnything", false)
+			},
+			assert: func(t *testing.T, err error) {
+				require.NoError(t, err)
+			},
+		},
+	}
+
+	describer := &drivertest.ChannelConn{
+		Desc: description.Server{Kind: description.ServerKindRSArbiter},
+	}
+	for _, tc := range cases {
+		tc := tc
+
+		t.Run(tc.name, func(t *testing.T) {
+			t.Parallel()
+
+			opt := options.Client().SetAuth(options.Credential{Username: "foo", Password: "bar"})
+			err := tc.set(opt)
+			require.NoError(t, err, "error setting authenticateToAnything: %v", err)
+			cfg, err := NewConfigFromOptionsWithAuthenticator(opt, nil, &testAuthenticator{})
+			require.NoError(t, err, "error constructing topology config: %v", err)
+
+			srvrCfg := newServerConfig(defaultConnectionTimeout, cfg.ServerOpts...)
+			connCfg := newConnectionConfig(srvrCfg.connectionOpts...)
+			err = connCfg.handshaker.FinishHandshake(context.TODO(), &mnet.Connection{Describer: describer})
+			tc.assert(t, err)
+		})
+	}
+}
+
 func TestTopologyNewConfig(t *testing.T) {
 	t.Run("default ServerSelectionTimeout", func(t *testing.T) {
 		cfg, err := NewConfig(options.Client(), nil)

From 466b4d002591e77da5ba5f91d5d98b44f60ae275 Mon Sep 17 00:00:00 2001
From: Qingyang Hu <qingyang.hu@mongodb.com>
Date: Fri, 25 Apr 2025 14:41:05 -0400
Subject: [PATCH 6/6] update tests

---
 x/mongo/driver/options/options_test.go | 31 +++++++++++++++++++++++---
 1 file changed, 28 insertions(+), 3 deletions(-)

diff --git a/x/mongo/driver/options/options_test.go b/x/mongo/driver/options/options_test.go
index 8c383e79ee..0cbab93444 100644
--- a/x/mongo/driver/options/options_test.go
+++ b/x/mongo/driver/options/options_test.go
@@ -7,6 +7,7 @@
 package options
 
 import (
+	"fmt"
 	"testing"
 
 	internalOptions "go.mongodb.org/mongo-driver/v2/internal/options"
@@ -31,7 +32,7 @@ func TestSetInternalClientOptions(t *testing.T) {
 	for _, tc := range cases {
 		tc := tc
 
-		t.Run(tc.key, func(t *testing.T) {
+		t.Run(fmt.Sprintf("set %s", tc.key), func(t *testing.T) {
 			t.Parallel()
 
 			opts := options.Client()
@@ -42,7 +43,7 @@ func TestSetInternalClientOptions(t *testing.T) {
 		})
 	}
 
-	t.Run("crypt", func(t *testing.T) {
+	t.Run("set crypt", func(t *testing.T) {
 		t.Parallel()
 
 		c := driver.NewCrypt(&driver.CryptOptions{})
@@ -52,7 +53,15 @@ func TestSetInternalClientOptions(t *testing.T) {
 		require.Equal(t, c, opts.Crypt, "expected %v, got %v", c, opts.Crypt)
 	})
 
-	t.Run("deployment", func(t *testing.T) {
+	t.Run("set crypt - wrong type", func(t *testing.T) {
+		t.Parallel()
+
+		opts := options.Client()
+		err := SetInternalClientOptions(opts, "crypt", &drivertest.MockDeployment{})
+		require.EqualError(t, err, "unexpected type for crypt")
+	})
+
+	t.Run("set deployment", func(t *testing.T) {
 		t.Parallel()
 
 		d := &drivertest.MockDeployment{}
@@ -61,4 +70,20 @@ func TestSetInternalClientOptions(t *testing.T) {
 		require.NoError(t, err, "error setting deployment: %v", err)
 		require.Equal(t, d, opts.Deployment, "expected %v, got %v", d, opts.Deployment)
 	})
+
+	t.Run("set deployment - wrong type", func(t *testing.T) {
+		t.Parallel()
+
+		opts := options.Client()
+		err := SetInternalClientOptions(opts, "deployment", driver.NewCrypt(&driver.CryptOptions{}))
+		require.EqualError(t, err, "unexpected type for deployment")
+	})
+
+	t.Run("set unsupported option", func(t *testing.T) {
+		t.Parallel()
+
+		opts := options.Client()
+		err := SetInternalClientOptions(opts, "unsupported", "unsupported")
+		require.EqualError(t, err, "unsupported option: unsupported")
+	})
 }