clientv3: panic if ActiveConnection tries to return non-nil connection

clientv3/client.go

@@ -292,6 +292,9 @@ func newClient(cfg *Config) (*Client, error) {
 func (c *Client) ActiveConnection() *grpc.ClientConn {
 	c.mu.RLock()
 	defer c.mu.RUnlock()
+	if c.conn == nil {
+		panic("trying to return nil active connection")
+	}
 	return c.conn
 }
 

clientv3/txn_test.go

@@ -20,7 +20,7 @@ import (
 )
 
 func TestTxnPanics(t *testing.T) {
-	kv := NewKV(&Client{})
+	kv := &kv{}
 
 	errc := make(chan string)
 	df := func() {