Implement estimateRouteFee

index.js

@@ -78,6 +78,7 @@ const {getPublicKey} = require('./lnd_methods');
 const {getRouteConfidence} = require('./lnd_methods');
 const {getRouteThroughHops} = require('./lnd_methods');
 const {getRouteToDestination} = require('./lnd_methods');
+const {getRoutingFeeEstimate} = require('./lnd_methods');
 const {getSettlementStatus} = require('./lnd_methods');
 const {getSweepTransactions} = require('./lnd_methods');
 const {getTowerServerInfo} = require('./lnd_methods');
@@ -239,6 +240,7 @@ module.exports = {
   getRouteConfidence,
   getRouteThroughHops,
   getRouteToDestination,
+  getRoutingFeeEstimate,
   getSettlementStatus,
   getSweepTransactions,
   getTowerServerInfo,

lnd_methods/index.js

@@ -77,6 +77,7 @@ const {getPublicKey} = require('./address');
 const {getRouteConfidence} = require('./generic');
 const {getRouteThroughHops} = require('./offchain');
 const {getRouteToDestination} = require('./info');
+const {getRoutingFeeEstimate} = require('./offchain');
 const {getSettlementStatus} = require('./offchain');
 const {getSweepTransactions} = require('./onchain');
 const {getTowerServerInfo} = require('./info');
@@ -237,6 +238,7 @@ module.exports = {
   getRouteConfidence,
   getRouteThroughHops,
   getRouteToDestination,
+  getRoutingFeeEstimate,
   getSettlementStatus,
   getSweepTransactions,
   getTowerServerInfo,

lnd_methods/offchain/get_routing_fee_estimate.d.ts

@@ -0,0 +1,32 @@
+import {AuthenticatedLnd} from '../../lnd_grpc';
+import {
+    AuthenticatedLightningArgs,
+    AuthenticatedLightningMethod
+} from '../../typescript';
+
+export type GetRoutingFeeEstimateRequest = AuthenticatedLightningArgs<{
+    lnd: AuthenticatedLnd;
+    /** BOLT 11 Encoded Payment Request */
+    request: string;
+    /** Optional Timeout in Milliseconds */
+    timeout: number;
+}>;
+
+export type GetRoutingFeeEstimateResponse = {
+    /** Sats (Routing Fee Sats) */
+    fee: number;
+    /** Timeout (Time Lock Delay) */
+    timeout: string;
+};
+
+/**
+ * Estimate routing fees based on an invoice.
+ *
+ * Requires `offchain:read` permission
+ *
+ * This method is not supported before LND 0.18.4
+ */
+export const getRoutingFeeEstimate: AuthenticatedLightningMethod<
+  GetRoutingFeeEstimateRequest,
+  GetRoutingFeeEstimateResponse
+>;

lnd_methods/offchain/get_routing_fee_estimate.js

@@ -0,0 +1,90 @@
+const asyncAuto = require('async/auto');
+const {returnResult} = require('asyncjs-util');
+
+/**
+ * Estimate routing fees based on an invoice.
+ *
+ * Requires `offchain:read` permission
+ *
+ * This method is not supported before LND 0.18.4
+ *
+ @argument
+ {
+    lnd: <Authenticated LND API Object>
+    request: <BOLT 11 Payment Request String>
+    timeout: <Optional Timeout in Milliseconds Number>
+  }
+
+  @returns via cbk or Promise
+  {
+    fee: <Route Fee Sats Number>
+    timeout: <Time Lock Block Height Delay String>
+  }
+ */
+module.exports = ({lnd, request, timeout}, cbk) => {
+  return new Promise((resolve, reject) => {
+    return asyncAuto({
+      // Check arguments
+      validate: cbk => {
+        if (!lnd || !lnd.router) {
+          return cbk([400, 'ExpectedAuthenticatedLndForGetRoutingFeeEstimate']);
+        }
+
+        if (!request) {
+          return cbk([400, 'ExpectedPaymentRequestStringForGetRoutingFeeEstimate']);
+        }
+
+        if (timeout > 86400000) {
+          return cbk([400, 'ExpectedTimeoutLessThanOneDayForGetRoutingFeeEstimate']);
+        }
+
+        if (timeout < 1) {
+          return cbk([400, 'ExpectedTimeoutGreaterThanZeroForGetRoutingFeeEstimate']);
+        }
+
+        timeout = !timeout ? 60 : timeout / 1000;
+
+        return cbk();
+      },
+
+      // Estimate route fee and return a successful routing fee and timeout or failure reason
+      getEstimate: ['validate', ({}, cbk) => {
+        return lnd.router.estimateRouteFee({request, timeout},
+          (err, res) => {
+            if (err) {
+              return cbk([503, 'UnexpectedGetRoutingFeeEstimateError', {err}]);
+            }
+
+            if (!res) {
+              return cbk([503, 'ExpectedGetRoutingFeeEstimateResponse']);
+            }
+
+            const mtokenFee = Number(res.fee);
+            if (!mtokenFee) {
+              return cbk([503, 'ExpectedFeeInGetRoutingFeeEstimateResponse']);
+            }
+
+            if (isNaN(mtokenFee)) {
+              return cbk([503, 'ExpectedFeeInGetRoutingFeeEstimateResponseToBeNumber']);
+            }
+
+            if (!isFinite(mtokenFee)) {
+              return cbk([503, 'ExpectedFeeInGetRoutingFeeEstimateResponseToBeFinite']);
+            }
+
+            if (!res.timeout) {
+              return cbk([503, 'ExpectedTimeoutInGetRoutingFeeEstimateResponse']);
+            }
+
+            if (res.failure_reason !== 'FAILURE_REASON_NONE') {
+              return cbk([404, 'GetRoutingFeeEstimateFailed', {failure: res.failure_reason}])
+            }
+
+            const fee = mtokenFee > 0 ? mtokenFee / 1000 : mtokenFee;
+            return cbk(null, {fee, timeout: res.timeout});
+          });
+      }],
+    },
+      returnResult({reject, resolve, of: 'getEstimate'}, cbk));
+  });
+};

lnd_methods/offchain/index.d.ts

@@ -27,6 +27,7 @@ export * from './get_payments';
 export * from './get_pending_channels';
 export * from './get_pending_payments';
 export * from './get_route_through_hops';
+export * from './get_routing_fee_estimate';
 export * from './get_settlement_status';
 export * from './is_destination_payable';
 export * from './pay_via_payment_details';

lnd_methods/offchain/index.js

@@ -27,6 +27,7 @@ const getPayments = require('./get_payments');
 const getPendingChannels = require('./get_pending_channels');
 const getPendingPayments = require('./get_pending_payments');
 const getRouteThroughHops = require('./get_route_through_hops');
+const getRoutingFeeEstimate = require('./get_routing_fee_estimate');
 const getSettlementStatus = require('./get_settlement_status');
 const isDestinationPayable = require('./is_destination_payable');
 const pay = require('./pay');
@@ -86,6 +87,7 @@ module.exports = {
   getPendingChannels,
   getPendingPayments,
   getRouteThroughHops,
+  getRoutingFeeEstimate,
   getSettlementStatus,
   isDestinationPayable,
   pay,

test/lnd_methods/offchain/test_get_routing_fee_estimate.js

@@ -0,0 +1,70 @@
+const {rejects, deepStrictEqual} = require('node:assert').strict;
+const test = require('node:test');
+const getRoutingFeeEstimate = require('../../../lnd_methods/offchain/get_routing_fee_estimate');
+
+const request = 'lnbcrt500u1pnh3r5dpp57cppte59jvmxnaunh03ecy6wchq8e0zh70n0nzsamaxztqxevcusdqqcqzzsxqyz5vqsp587ua488ttsts8cs97ekt9axdla3jmq4mj2h7xj7g6rw37fu65yqs9qxpqysgql27u5p9m2xv0r0pjykzvcgs88azzfkywzw2xw5q6u86qnwzrut94mks86zxelhltdtn6vnqgd8hay433wwq7uvple709gp7pmwmtzwcqakyevc';
+
+/** Function */
+const makeLnd = ({err, res}) => {
+  const response = {
+    fee: 1050,
+    timeout: '3520',
+    failure_reason: 'FAILURE_REASON_NONE'
+  };
+  return {
+    router: {
+      estimateRouteFee: ({}, cbk) => cbk(err, res !== undefined ? res : response),
+    }
+  };
+};
+
+const makeArgs = override => {
+  const args = {request, timeout: 60000, lnd: makeLnd({})};
+  Object.keys(override || {}).forEach(key => args[key] = override[key]);
+  return args;
+};
+
+const tests = [
+  {
+    args: makeArgs({lnd: undefined}),
+    description: 'LND is required',
+    error: [400, 'ExpectedAuthenticatedLndForGetRoutingFeeEstimate'],
+  },
+  {
+    args: makeArgs({request: undefined}),
+    description: 'Request is required',
+    error: [400, 'ExpectedPaymentRequestStringForGetRoutingFeeEstimate'],
+  },
+  {
+    args: makeArgs({timeout: 86400001}),
+    description: 'Timeout must be less than or equal to 86400000 milliseconds',
+    error: [400, 'ExpectedTimeoutLessThanOneDayForGetRoutingFeeEstimate'],
+  },
+  {
+    args: makeArgs({timeout: 0}),
+    description: 'Timeout must be greater than 0 milliseconds',
+    error: [400, 'ExpectedTimeoutGreaterThanZeroForGetRoutingFeeEstimate'],
+  },
+  {
+    args: makeArgs({request, lnd: makeLnd({})}),
+    description: 'A route fee number in sats is expected for default timeout 60000 milliseconds',
+    expected: {fee: 1.05, timeout: '3520'}
+  },
+  {
+    args: makeArgs({request, timeout: 86400000, lnd: makeLnd({})}),
+    description: 'A route fee number in sats is expected for timeout 86400000 milliseconds',
+    expected: {fee: 1.05, timeout: '3520'}
+  }
+];
+
+tests.forEach(({args, description, error, expected}) => {
+  return test(description, async () => {
+    if (!!error) {
+      await rejects(getRoutingFeeEstimate(args), error, 'Got expected error');
+    } else {
+      deepStrictEqual(await getRoutingFeeEstimate(args), expected, 'Got result');
+    }
+
+    return;
+  });
+});