Rewrite transaction parser and add unit test for getTransaction

src/api/ledger/parse/trustline.js

@@ -0,0 +1,21 @@
+'use strict';
+const assert = require('assert');
+const utils = require('./utils');
+const flags = utils.core.Transaction.flags.TrustSet;
+
+function parseTrustline(tx) {
+  assert(tx.TransactionType === 'TrustSet');
+
+  return {
+    limit: tx.LimitAmount.value,
+    currency: tx.LimitAmount.currency,
+    counterparty: tx.LimitAmount.issuer,
+    qualityIn: tx.QualityIn,
+    qualityOut: tx.QualityOut,
+    allowRippling: tx.Flags & flags.NoRipple === 0,
+    frozen: tx.Flags & flags.SetFreeze !== 0,
+    authorized: tx.Flags & flags.SetAuth !== 0
+  };
+}
+
+module.exports = parseTrustline;