Merge pull request #1467 from ExchangeUnion/rpc/channel-push

feat(rpc): push amount in OpenChannel call

lib/cli/commands/openchannel.ts

@@ -3,7 +3,7 @@ import { callback, loadXudClient } from '../command';
 import { OpenChannelRequest } from '../../proto/xudrpc_pb';
 import { coinsToSats } from '../utils';
 
-export const command = 'openchannel <node_identifier> <currency> <amount>';
+export const command = 'openchannel <node_identifier> <currency> <amount> [push_amount]';
 
 export const describe = 'open a payment channel with a peer';
 
@@ -20,12 +20,17 @@ export const builder = {
     type: 'number',
     description: 'the amount to be deposited into the channel',
   },
+  push_amount: {
+    type: 'number',
+    description: 'the amount to be pushed to the remote side of the channel',
+  },
 };
 
 export const handler = (argv: Arguments<any>) => {
   const request = new OpenChannelRequest();
   request.setNodeIdentifier(argv.node_identifier);
   request.setCurrency(argv.currency.toUpperCase());
   request.setAmount(coinsToSats(argv.amount));
+  request.setPushAmount(coinsToSats(argv.amount));
   loadXudClient(argv).openChannel(request, callback(argv));
 };

lib/lndclient/LndClient.ts

@@ -718,12 +718,12 @@ class LndClient extends SwapClient {
    * Opens a channel given peerPubKey and amount.
    */
   public openChannel = async (
-    { peerIdentifier: peerPubKey, units, lndUris }:
-    { peerIdentifier: string, units: number, lndUris: string[] },
+    { peerIdentifier: peerPubKey, units, lndUris, pushUnits = 0 }:
+    { peerIdentifier: string, units: number, lndUris: string[], pushUnits?: number },
   ): Promise<void> => {
     const connectionEstablished = await this.connectPeerAddreses(lndUris);
     if (connectionEstablished) {
-      await this.openChannelSync(peerPubKey, units);
+      await this.openChannelSync(peerPubKey, units, pushUnits);
     } else {
       throw new Error(`could not connect to lnd uris for ${peerPubKey}`);
     }
@@ -762,10 +762,11 @@ class LndClient extends SwapClient {
   /**
    * Opens a channel with a connected lnd node.
    */
-  private openChannelSync = (node_pubkey_string: string, local_funding_amount: number): Promise<lndrpc.ChannelPoint> => {
+  private openChannelSync = (nodePubkeyString: string, localFundingAmount: number, pushSat = 0): Promise<lndrpc.ChannelPoint> => {
     const request = new lndrpc.OpenChannelRequest;
-    request.setNodePubkeyString(node_pubkey_string);
-    request.setLocalFundingAmount(local_funding_amount);
+    request.setNodePubkeyString(nodePubkeyString);
+    request.setLocalFundingAmount(localFundingAmount);
+    request.setPushSat(pushSat);
     return this.unaryCall<lndrpc.OpenChannelRequest, lndrpc.ChannelPoint>('openChannelSync', request);
   }
 

lib/service/Service.ts

@@ -240,9 +240,9 @@ class Service {
    * Opens a payment channel to a specified node, currency and amount.
    */
   public openChannel = async (
-    args: { nodeIdentifier: string, amount: number, currency: string },
+    args: { nodeIdentifier: string, amount: number, currency: string, pushAmount?: number },
   ) => {
-    const { nodeIdentifier, amount, currency } = args;
+    const { nodeIdentifier, amount, currency, pushAmount } = args;
     argChecks.HAS_NODE_IDENTIFIER({ nodeIdentifier });
     argChecks.POSITIVE_AMOUNT({ amount });
     argChecks.VALID_CURRENCY({ currency });
@@ -253,6 +253,7 @@ class Service {
         peer,
         amount,
         currency,
+        pushAmount,
       });
     } catch (e) {
       const errorMessage = e.message || 'unknown';

lib/swaps/SwapClient.ts

@@ -278,12 +278,13 @@ abstract class SwapClient extends EventEmitter {
    * optional currency and optional lndUris.
    */
   public abstract async openChannel(
-    { peerIdentifier, units, currency, lndUris }:
+    { peerIdentifier, units, currency, lndUris, pushUnits }:
     {
       peerIdentifier: string,
       units: number,
       currency?: string,
       lndUris?: string[],
+      pushUnits?: number,
     },
   ): Promise<void>;
 

lib/swaps/SwapClientManager.ts

@@ -393,8 +393,8 @@ class SwapClientManager extends EventEmitter {
    * @returns Nothing upon success, throws otherwise.
    */
   public openChannel = async (
-    { peer, amount, currency }:
-    { peer: Peer, amount: number, currency: string },
+    { peer, amount, currency, pushAmount = 0 }:
+    { peer: Peer, amount: number, currency: string, pushAmount?: number },
   ): Promise<void> => {
     const swapClient = this.get(currency);
     if (!swapClient) {
@@ -408,12 +408,17 @@ class SwapClientManager extends EventEmitter {
       amount,
       currency,
     });
+    const pushUnits = this.unitConverter.amountToUnits({
+      currency,
+      amount: pushAmount,
+    });
+
     if (isLndClient(swapClient)) {
       const lndUris = peer.getLndUris(currency);
       if (!lndUris) {
         throw new Error('unable to get lnd listening uris');
       }
-      await swapClient.openChannel({ peerIdentifier, units, lndUris });
+      await swapClient.openChannel({ peerIdentifier, units, lndUris, pushUnits });
       return;
     }
     // fallback to raiden for all non-lnd currencies

proto/xudrpc.proto

@@ -507,8 +507,10 @@ message OpenChannelRequest {
   string node_identifier = 1 [json_name = "node_identifier"];
   // The ticker symbol of the currency to open the channel for.
   string currency = 2 [json_name = "currency"];
-  // The amount of the channel denominated in satoshis.
+  // The amount to be deposited into the channel denominated in satoshis.
   int64 amount = 3 [json_name = "amount"];
+  // The balance amount to be pushed to the remote side of the channel denominated in satoshis.
+  uint64 push_amount = 4 [json_name = "push_amount"];
 }
 
 message OpenChannelResponse {}

test/jest/LndClient.spec.ts

@@ -123,7 +123,29 @@ describe('LndClient', () => {
         .toHaveBeenCalledWith(peerPubKey, externalIp1);
       expect(lnd['openChannelSync']).toHaveBeenCalledTimes(1);
       expect(lnd['openChannelSync'])
-        .toHaveBeenCalledWith(peerPubKey, units);
+        .toHaveBeenCalledWith(peerPubKey, units, 0);
+    });
+
+    test('it pushes satoshis to the peer when specified', async () => {
+      expect.assertions(4);
+      const pushUnits = 481824;
+      lnd['openChannelSync'] = jest.fn().mockReturnValue(Promise.resolve());
+      lnd['connectPeer'] = jest.fn()
+        .mockImplementationOnce(() => {
+          return Promise.resolve();
+        });
+      await lnd.openChannel({
+        units,
+        pushUnits,
+        peerIdentifier: peerPubKey,
+        lndUris: lndListeningUris,
+      });
+      expect(lnd['connectPeer']).toHaveBeenCalledTimes(1);
+      expect(lnd['connectPeer'])
+        .toHaveBeenCalledWith(peerPubKey, externalIp1);
+      expect(lnd['openChannelSync']).toHaveBeenCalledTimes(1);
+      expect(lnd['openChannelSync'])
+        .toHaveBeenCalledWith(peerPubKey, units, pushUnits);
     });
 
     test('it stops trying to connect to lnd uris when first once succeeds', async () => {