Fix getPaths (#930)

* getPaths:
  * Filter paths correctly
  * Use correct value when XRP is the destination currency

src/ledger/pathfind.ts

@@ -1,7 +1,13 @@
 import * as _ from 'lodash'
 import BigNumber from 'bignumber.js'
 import {getXRPBalance, renameCounterpartyToIssuer} from './utils'
-import {validate, toRippledAmount, errors} from '../common'
+import {
+  validate,
+  toRippledAmount,
+  errors,
+  xrpToDrops,
+  dropsToXrp
+} from '../common'
 import {Connection} from '../common'
 import parsePathfind from './parse/pathfind'
 import {RippledAmount, Amount} from '../common/types/objects'
@@ -23,7 +29,11 @@ function addParams(request: PathFindRequest, result: RippledPathsResponse
 function requestPathFind(connection: Connection, pathfind: PathFind
 ): Promise<RippledPathsResponse> {
   const destinationAmount: Amount = _.assign(
-    {value: '-1'},
+    {
+      // This is converted back to drops by toRippledAmount()
+      value: pathfind.destination.amount.currency === 'XRP' ?
+        dropsToXrp('-1') : '-1'
+    },
     pathfind.destination.amount
   )
   const request: PathFindRequest = {
@@ -95,13 +105,21 @@ function filterSourceFundsLowPaths(pathfind: PathFind,
 ): RippledPathsResponse {
   if (pathfind.source.amount &&
       pathfind.destination.amount.value === undefined && paths.alternatives) {
-    paths.alternatives = _.filter(paths.alternatives, alt =>
+    paths.alternatives = _.filter(paths.alternatives, alt => {
-        !!alt.source_amount &&
+      if (!alt.source_amount) {
-        !!pathfind.source.amount &&
+        return false
-        // TODO: Returns false when alt.source_amount is a string. Fix?
+      }
-        typeof alt.source_amount !== 'string' &&
+      const pathfindSourceAmountValue = new BigNumber(
-        new BigNumber(alt.source_amount.value).eq(pathfind.source.amount.value)
+        pathfind.source.amount.currency === 'XRP' ?
-    )
+        xrpToDrops(pathfind.source.amount.value) :
+        pathfind.source.amount.value)
+      const altSourceAmountValue = new BigNumber(
+        typeof alt.source_amount === 'string' ?
+        alt.source_amount :
+        alt.source_amount.value
+      )
+      return altSourceAmountValue.eq(pathfindSourceAmountValue)
+    })
   }
   return paths
 }

test/api-test.js

@@ -2328,6 +2328,45 @@ describe('RippleAPI', function () {
       _.partial(checkResult, responses.getPaths.XrpToUsd, 'getPaths'));
   });
 
+  it('getPaths - result path has source_amount in drops', function () {
+    return this.api.getPaths({
+      source: {
+        address: 'rB2NTuTTS3eNCsWxZYzJ4wqRqxNLZqA9Vx',
+        amount: {
+          value: this.api.dropsToXrp(1000000),
+          currency: 'XRP'
+        }
+      },
+      destination: {
+        address: 'rhpJkBfZGQyT1xeDbwtKEuSrSXw3QZSAy5',
+        amount: {
+          counterparty: 'rGpGaj4sxEZGenW1prqER25EUi7x4fqK9u',
+          currency: 'EUR'
+        }
+      }
+    }).then(
+      _.partial(checkResult, [
+        {
+          "source": {
+            "address": "rB2NTuTTS3eNCsWxZYzJ4wqRqxNLZqA9Vx",
+            "amount": {
+              "currency": "XRP",
+              "value": "1"
+            }
+          },
+          "destination": {
+            "address": "rhpJkBfZGQyT1xeDbwtKEuSrSXw3QZSAy5",
+            "minAmount": {
+              "currency": "EUR",
+              "value": "1",
+              "counterparty": "rGpGaj4sxEZGenW1prqER25EUi7x4fqK9u"
+            }
+          },
+          "paths": "[[{\"currency\":\"USD\",\"issuer\":\"rGpGaj4sxEZGenW1prqER25EUi7x4fqK9u\"},{\"currency\":\"EUR\",\"issuer\":\"rGpGaj4sxEZGenW1prqER25EUi7x4fqK9u\"}]]"
+        }
+      ], 'getPaths'));
+  });
+
   it('getPaths - queuing', function () {
     return Promise.all([
       this.api.getPaths(requests.getPaths.normal),

test/mock-rippled.js

@@ -485,7 +485,57 @@ module.exports = function createMockRippled(port) {
     if (request.subcommand === 'close') {   // for path_find command
       return;
     }
-    if (request.source_account === addresses.NOTFOUND) {
+    if (request.source_account === 'rB2NTuTTS3eNCsWxZYzJ4wqRqxNLZqA9Vx') {
+      // getPaths - result path has source_amount in drops
+      response = createResponse(request, {
+        "id": 0,
+        "type": "response",
+        "status": "success",
+        "result": {
+          "alternatives": [
+            {
+              "destination_amount": {
+                "currency": "EUR",
+                "issuer": "rGpGaj4sxEZGenW1prqER25EUi7x4fqK9u",
+                "value": "1"
+              },
+              "paths_canonical": [],
+              "paths_computed": [
+                [
+                  {
+                    "currency": "USD",
+                    "issuer": "rGpGaj4sxEZGenW1prqER25EUi7x4fqK9u",
+                    "type": 48,
+                    "type_hex": "0000000000000030"
+                  },
+                  {
+                    "currency": "EUR",
+                    "issuer": "rGpGaj4sxEZGenW1prqER25EUi7x4fqK9u",
+                    "type": 48,
+                    "type_hex": "0000000000000030"
+                  }
+                ]
+              ],
+              "source_amount": "1000000"
+            }
+          ],
+          "destination_account": "rhpJkBfZGQyT1xeDbwtKEuSrSXw3QZSAy5",
+          "destination_amount": {
+            "currency": "EUR",
+            "issuer": "rGpGaj4sxEZGenW1prqER25EUi7x4fqK9u",
+            "value": "-1"
+          },
+          "destination_currencies": [
+            "EUR",
+            "XRP"
+          ],
+          "full_reply": true,
+          "id": 2,
+          "source_account": "rB2NTuTTS3eNCsWxZYzJ4wqRqxNLZqA9Vx",
+          "status": "success"
+        }
+      })
+    } else if (request.source_account === addresses.NOTFOUND) {
       response = createResponse(request, fixtures.path_find.srcActNotFound);
     } else if (request.source_account === addresses.SOURCE_LOW_FUNDS) {
       response = createResponse(request, fixtures.path_find.sourceAmountLow);
@@ -497,8 +547,9 @@ module.exports = function createMockRippled(port) {
         destination_address: request.destination_address
       });
     } else if (request.source_account === addresses.ACCOUNT) {
-      if (request.destination_account ===
+      if (request.destination_account === 'ra5nK24KXen9AHvsdFTKHSANinZseWnPcX' &&
-        'ra5nK24KXen9AHvsdFTKHSANinZseWnPcX') {
+          // Important: Ensure that destination_amount.value is correct
+          request.destination_amount.value === "-1") {
         response = createResponse(request, fixtures.path_find.sendAll);
       } else {
         response = fixtures.path_find.generate.generateIOUPaymentPaths(