// SendCoins attemps to send amt satoshis from the internal mining node to the
// targetted lightning node.
func (n *networkHarness) SendCoins(ctx context.Context, amt btcutil.Amount,
target *lightningNode) error {
balReq := &lnrpc.WalletBalanceRequest{}
initialBalance, err := target.WalletBalance(ctx, balReq)
if err != nil {
return err
}
// First, obtain an address from the target lightning node, preferring
// to receive a p2wkh address s.t the output can immediately be used as
// an input to a funding transaction.
addrReq := &lnrpc.NewAddressRequest{
Type: lnrpc.NewAddressRequest_WITNESS_PUBKEY_HASH,
}
resp, err := target.NewAddress(ctx, addrReq)
if err != nil {
return err
}
addr, err := btcutil.DecodeAddress(resp.Address, n.netParams)
if err != nil {
return err
}
addrScript, err := txscript.PayToAddrScript(addr)
if err != nil {
return err
}
// Generate a transaction which creates an output to the target
// pkScript of the desired amount.
output := &wire.TxOut{
PkScript: addrScript,
Value: int64(amt),
}
if _, err := n.Miner.CoinbaseSpend([]*wire.TxOut{output}); err != nil {
return err
}
// Finally, generate 6 new blocks to ensure the output gains a
// sufficient number of confirmations.
if _, err := n.Miner.Node.Generate(6); err != nil {
return err
}
// Pause until the nodes current wallet balances reflects the amount
// sent to it above.
// TODO(roasbeef): factor out into helper func
for {
select {
case <-time.Tick(time.Millisecond * 50):
currentBal, err := target.WalletBalance(ctx, balReq)
if err != nil {
return err
}
if currentBal.Balance == initialBalance.Balance+amt.ToBTC() {
return nil
}
case <-time.After(time.Second * 30):
return fmt.Errorf("balances not synced after deadline")
}
}
}
