Pass custom registry to topology options.

GODRIVER-681

Change-Id: I50ac9930acd72719274a03357a20eb841a346c32

Author: Divjot Arora

mongo/client_internal_test.go

@@ -22,12 +22,15 @@ import (
 
 	"time"
 
+	"github.com/mongodb/mongo-go-driver/bson/bsoncodec"
+	"github.com/mongodb/mongo-go-driver/bson/bsonrw"
 	"github.com/mongodb/mongo-go-driver/mongo/options"
 	"github.com/mongodb/mongo-go-driver/mongo/readpref"
 	"github.com/mongodb/mongo-go-driver/mongo/writeconcern"
 	"github.com/mongodb/mongo-go-driver/x/mongo/driver/session"
 	"github.com/mongodb/mongo-go-driver/x/mongo/driver/uuid"
 	"github.com/mongodb/mongo-go-driver/x/network/connstring"
+	"reflect"
 )
 
 func createTestClient(t *testing.T) *Client {
@@ -94,6 +97,62 @@ func TestClientOptions(t *testing.T) {
 	require.Equal(t, "test", c.connString.ReplicaSet)
 }
 
+type NewCodec struct {
+	ID int64 `bson:"_id"`
+}
+
+func (e *NewCodec) EncodeValue(ectx bsoncodec.EncodeContext, vw bsonrw.ValueWriter, val reflect.Value) error {
+	return vw.WriteInt64(val.Int())
+}
+
+// DecodeValue negates the value of ID when reading
+func (e *NewCodec) DecodeValue(ectx bsoncodec.DecodeContext, vr bsonrw.ValueReader, val reflect.Value) error {
+	i, err := vr.ReadInt64()
+	if err != nil {
+		return err
+	}
+
+	val.SetInt(i * -1)
+	return nil
+}
+
+func TestClientRegistryPassedToCursors(t *testing.T) {
+	// register a new codec for the int64 type that does the default encoding for an int64 and negates the value when
+	// decoding
+
+	rb := bson.NewRegistryBuilder()
+	cod := &NewCodec{}
+	rb.RegisterCodec(reflect.TypeOf(int64(0)), cod)
+
+	cs := testutil.ConnString(t)
+	client, err := NewClientWithOptions(cs.String(), options.Client().SetRegistry(rb.Build()))
+	require.NoError(t, err)
+	err = client.Connect(ctx)
+	require.NoError(t, err)
+
+	db := client.Database("TestRegistryDB")
+	defer func() {
+		_ = db.Drop(ctx)
+		_ = client.Disconnect(ctx)
+	}()
+
+	coll := db.Collection("TestRegistryColl")
+
+	_, err = coll.InsertOne(ctx, NewCodec{ID: 10})
+	require.NoError(t, err)
+
+	c, err := coll.Find(ctx, nil)
+	require.NoError(t, err)
+
+	require.True(t, c.Next(ctx))
+
+	var foundDoc NewCodec
+	err = c.Decode(&foundDoc)
+	require.NoError(t, err)
+
+	require.Equal(t, foundDoc.ID, int64(-10))
+}
+
 func TestClient_TLSConnection(t *testing.T) {
 	skipIfBelow30(t) // 3.0 doesn't return a security field in the serverStatus response
 	t.Parallel()

mongo/options/clientoptions.go

@@ -220,6 +220,19 @@ func (c *ClientOptions) SetReadPreference(rp *readpref.ReadPref) *ClientOptions
 func (c *ClientOptions) SetRegistry(registry *bsoncodec.Registry) *ClientOptions {
 	c.Registry = registry
 
+	// add registry to the server options so that it will be used for the cursors built by this client
+	c.TopologyOptions = append(
+		c.TopologyOptions,
+		topology.WithServerOptions(func(opts ...topology.ServerOption) []topology.ServerOption {
+			return append(
+				opts,
+				topology.WithRegistry(func(*bsoncodec.Registry) *bsoncodec.Registry {
+					return registry
+				}),
+			)
+		}),
+	)
+
 	return c
 }