Fix prepareTrustline with no quality setting

src/api/transaction/trustline.js

@@ -12,7 +12,8 @@ const TrustSetFlags = {
 };
 
 function convertQuality(quality) {
-  return (new BigNumber(quality)).shift(9).truncated().toNumber();
+  return quality === undefined ? undefined :
+    (new BigNumber(quality)).shift(9).truncated().toNumber();
 }
 
 function createTrustlineTransaction(account, trustline) {

test/api-test.js

@@ -93,10 +93,16 @@ describe('RippleAPI', function() {
       _.partial(checkResult, responses.prepareOrderCancellation, 'tx'));
   });
 
-  it('prepareTrustline', function() {
+  it('prepareTrustline - simple', function() {
     return this.api.prepareTrustline(
-      address, requests.prepareTrustline, instructions).then(
-        _.partial(checkResult, responses.prepareTrustline, 'tx'));
+      address, requests.prepareTrustline.simple, instructions).then(
+        _.partial(checkResult, responses.prepareTrustline.simple, 'tx'));
+  });
+
+  it('prepareTrustline - complex', function() {
+    return this.api.prepareTrustline(
+      address, requests.prepareTrustline.complex, instructions).then(
+        _.partial(checkResult, responses.prepareTrustline.complex, 'tx'));
   });
 
   it('prepareSettings', function() {

test/fixtures/api/requests/index.js

@@ -7,7 +7,10 @@ module.exports = {
   preparePaymentAllOptions: require('./prepare-payment-all-options'),
   preparePaymentNoCounterparty: require('./prepare-payment-no-counterparty'),
   prepareSettings: require('./prepare-settings'),
-  prepareTrustline: require('./prepare-trustline'),
+  prepareTrustline: {
+    simple: require('./prepare-trustline-simple'),
+    complex: require('./prepare-trustline')
+  },
   sign: require('./sign'),
   getPaths: {
     normal: require('./getpaths/normal'),

test/fixtures/api/requests/prepare-trustline-simple.json

@@ -0,0 +1,5 @@
+{
+  "currency": "BTC",
+  "counterparty": "rMH4UxPrbuMa1spCBR98hLLyNJp4d8p4tM",
+  "limit": "0.10"
+}

test/fixtures/api/responses/index.js

@@ -42,7 +42,10 @@ module.exports = {
     setTransferRate: require('./prepare-settings-set-transfer-rate.json'),
     fieldClear: require('./prepare-settings-field-clear.json')
   },
-  prepareTrustline: require('./prepare-trustline.json'),
+  prepareTrustline: {
+    simple: require('./prepare-trustline-simple.json'),
+    complex: require('./prepare-trustline.json')
+  },
   sign: require('./sign.json'),
   submit: require('./submit.json')
 };

test/fixtures/api/responses/prepare-trustline-simple.json

@@ -0,0 +1,13 @@
+{
+  "Flags": 0,
+  "TransactionType": "TrustSet",
+  "Account": "r9cZA1mLK5R5Am25ArfXFmqgNwjZgnfk59",
+  "LimitAmount": {
+    "value": "0.1",
+    "currency": "BTC",
+    "issuer": "rMH4UxPrbuMa1spCBR98hLLyNJp4d8p4tM"
+  },
+  "LastLedgerSequence": 8820051,
+  "Fee": "12",
+  "Sequence": 23
+}