Make our own low-level driver for testing

internal/driver/driver.go

@@ -166,6 +166,14 @@
 
 // Request sends the given request to the connection and returns the response.
 func (c *Conn) Request(ctx context.Context, header *wire.MsgHeader, body wire.MsgBody) (*wire.MsgHeader, wire.MsgBody, error) {
-	// TODO https://github.com/FerretDB/FerretDB/issues/4146
-	panic("not implemented")
+	if err := c.Write(header, body); err != nil {
+		return nil, nil, lazyerrors.Error(err)
+	}
+
+	header, body, err := c.Read()
+	if err != nil {
+		return nil, nil, lazyerrors.Error(err)
+	}
+
+	return header, body, nil
 }

internal/driver/driver_test.go

@@ -19,7 +19,10 @@
 
 	"github.com/stretchr/testify/require"
 
+	"github.com/FerretDB/FerretDB/internal/bson"
+	"github.com/FerretDB/FerretDB/internal/util/must"
 	"github.com/FerretDB/FerretDB/internal/util/testutil"
+	"github.com/FerretDB/FerretDB/internal/wire"
 )
 
 func TestDriver(t *testing.T) {
@@ -33,6 +36,81 @@
 	require.NoError(t, err)
 	t.Cleanup(func() { require.NoError(t, c.Close()) })
 
-	// TODO https://github.com/FerretDB/FerretDB/issues/4146
-	_ = c
+	t.Run("Insert", func(t *testing.T) {
+		doc := must.NotFail(bson.NewDocument(
+			"insert", "values",
+			"documents", must.NotFail(bson.NewArray(
+				must.NotFail(bson.NewDocument("v", int32(1), "_id", bson.ObjectID([]byte("65f83bddef2048e47170b641")))),
+				must.NotFail(bson.NewDocument("v", int32(2), "_id", bson.ObjectID([]byte("65f83bddef2048e47170b642")))),
+			)),
+			"ordered", true,
+			"lsid", int32(0),
+			"txnNumber", int64(1),
+			"$db", "test",
+		))
+
+		section, err := must.NotFail(bson.NewDocument(
+			"Kind", int32(0),
+			"Document", doc,
+		)).Encode()
+
+		require.NoError(t, err)
+
+		body, err := wire.NewOpMsg(section)
+		require.NoError(t, err)
+
+		msgBin, err := body.MarshalBinary()
+		require.NoError(t, err)
+
+		// TODO verify header
+		header := wire.MsgHeader{
+			MessageLength: int32(len(msgBin) + wire.MsgHeaderLen),
+			RequestID:     13,
+			OpCode:        wire.OpCodeMsg,
+		}
+
+		//resHeader, resBody, err := c.Request(ctx, &header, body)
+		_, _, err = c.Request(ctx, &header, body)
+		require.NoError(t, err)
+
+		//	assert.Equal(t, wire.MsgHeader{
+		//		RequestID:     368,
+		//		ResponseTo:    13,
+		//		OpCode:        2013,
+		//		MessageLength: 252,
+		//	}, *resHeader)
+		//	assert.Equal(t, wire.OpMsg{}, resBody)
+	})
+
+	t.Run("Find", func(t *testing.T) {
+		doc := must.NotFail(bson.NewDocument(
+			"find", "values",
+			"filter", must.NotFail(bson.NewDocument()),
+			"lsid", int32(0),
+			"$db", "test",
+		))
+
+		section, err := must.NotFail(bson.NewDocument(
+			"Kind", int32(0),
+			"Document", doc,
+		)).Encode()
+		require.NoError(t, err)
+
+		body, err := wire.NewOpMsg(section)
+		require.NoError(t, err)
+
+		msgBin, err := body.MarshalBinary()
+		require.NoError(t, err)
+
+		// TODO verify header
+		header := wire.MsgHeader{
+			MessageLength: int32(len(msgBin) + wire.MsgHeaderLen),
+			RequestID:     13,
+			OpCode:        wire.OpCodeMsg,
+		}
+
+		_, resBody, err := c.Request(ctx, &header, body)
+		require.NoError(t, err)
+
+	})
 }