Convert server methods, add unit tests, and cleanup

src/api/server/server.js

@@ -1,33 +1,45 @@
 'use strict';
 const common = require('../common');
 
+// If a ledger is not received in this time, consider the connection offline
+const CONNECTION_TIMEOUT = 1000 * 30;
+
 function connect(callback) {
   this.remote.connect(callback);
 }
 
-function isConnected() {
-  return common.server.isConnected(this.remote);
+function disconnect(callback) {
+  this.remote.disconnect(callback);
 }
 
-function getServerStatus(callback) {
-  common.server.getStatus(this.remote, function(error, status) {
+function isUpToDate(remote) {
+  const server = remote.getServer();
+  return Boolean(server) && (remote._stand_alone
+    || (Date.now() - server._lastLedgerClose) <= CONNECTION_TIMEOUT);
+}
+
+function isConnected() {
+  return Boolean(this.remote._ledger_current_index) && isUpToDate(this.remote);
+}
+
+function getServerInfo(callback) {
+  this.remote.requestServerInfo((error, info) => {
     if (error) {
       callback(new common.errors.RippledNetworkError(error.message));
     } else {
-      callback(null, status);
+      callback(null, info);
     }
   });
 }
 
-function getFee(callback) {
-  const fee = this.remote.createTransaction()._computeFee();
-  callback(null, {fee: common.dropsToXrp(fee)});
+function getFee() {
+  return common.dropsToXrp(this.remote.createTransaction()._computeFee());
 }
 
-
 module.exports = {
   connect: connect,
+  disconnect: disconnect,
   isConnected: isConnected,
-  getServerStatus: getServerStatus,
+  getServerInfo: getServerInfo,
   getFee: getFee
 };