feat(accounts): debounce read request

This commit adds a debounce() call to the read request.  Since it uses
promises and Angular's $timeout(), it will require flushing the
$timeouts in tests.

Closes Third-Culture-Software#2892.

client/src/js/services/debounce.js

@@ -0,0 +1,41 @@
+angular.module('bhima.services')
+  .factory('debounce', ['$timeout', '$q', ($timeout, $q) => {
+
+    // The service is actually this function, which we call with the func
+    // that should be debounced and how long to wait in between calls
+    return function debounce(func, wait, immediate) {
+      let timeout;
+      // Create a deferred object that will be resolved when we need to
+      // actually call the func
+      let deferred = $q.defer();
+
+      return function fn() {
+        const context = this;
+
+        // eslint-disable-next-line prefer-rest-params
+        const args = arguments;
+
+        const later = function () {
+          timeout = null;
+          if (!immediate) {
+            deferred.resolve(func.apply(context, args));
+            deferred = $q.defer();
+          }
+        };
+
+        const callNow = immediate && !timeout;
+        if (timeout) {
+          $timeout.cancel(timeout);
+        }
+
+        timeout = $timeout(later, wait);
+
+        if (callNow) {
+          deferred.resolve(func.apply(context, args));
+          deferred = $q.defer();
+        }
+
+        return deferred.promise;
+      };
+    };
+  }]);

client/src/modules/accounts/accounts.service.js

@@ -2,19 +2,20 @@ angular.module('bhima.services')
   .service('AccountService', AccountService);
 
 AccountService.$inject = [
-  'PrototypeApiService', 'bhConstants',
+  'PrototypeApiService', 'bhConstants', 'debounce',
 ];
 
 /**
  * Account Service
  *
  * A service wrapper for the /accounts HTTP endpoint.
  */
-function AccountService(Api, bhConstants) {
+function AccountService(Api, bhConstants, debounce) {
   const baseUrl = '/accounts/';
   const service = new Api(baseUrl);
 
-  service.read = read;
+  // debounce the read() method by 250 milliseconds to avoid needless GET requests
+  service.read = debounce(read, 150, false);
   service.label = label;
 
   service.getBalance = getBalance;
@@ -41,6 +42,7 @@ function AccountService(Api, bhConstants) {
       .then(service.util.unwrapHttpResponse);
   }
 
+
   /**
    * The read() method loads data from the api endpoint. If an id is provided,
    * the $http promise is resolved with a single JSON object, otherwise an array

client/src/modules/cash/modals/transfer-modal.ctrl.js

@@ -3,7 +3,7 @@ angular.module('bhima.controllers')
 
 CashTransferModalController.$inject = [
   'CurrencyService', 'VoucherService', 'CashboxService', 'AccountService', 'SessionService',
-  'CashService', '$state', 'NotifyService', 'ReceiptModal', 'bhConstants', 'VoucherForm'
+  'CashService', '$state', 'NotifyService', 'ReceiptModal', 'bhConstants', 'VoucherForm',
 ];
 
 /**
@@ -12,32 +12,35 @@ CashTransferModalController.$inject = [
  * @description
  * This controller is responsible transferring money between a cashbox and a transfer account.
  */
-function CashTransferModalController(Currencies, Vouchers, Cashboxes, Accounts, Session, Cash, $state, Notify, Receipts, bhConstants, VoucherForm) {
-  var vm = this;
+function CashTransferModalController(
+  Currencies, Vouchers, Cashboxes, Accounts, Session, Cash, $state, Notify,
+  Receipts, bhConstants, VoucherForm
+) {
+  const vm = this;
 
   vm.voucher = new VoucherForm('CashTransferForm');
 
-  var TRANSFER_TYPE_ID = bhConstants.transactionType.TRANSFER;
+  const TRANSFER_TYPE_ID = bhConstants.transactionType.TRANSFER;
 
   vm.loadAccountDetails = loadAccountDetails;
   vm.submit = submit;
 
   // submit and close the modal
   function submit(form) {
-    if (form.$invalid) { return; }
+    if (form.$invalid) { return 0; }
 
-    var record = prepareVoucherRecord();
+    const record = prepareVoucherRecord();
 
     // validate
-    var validation = vm.voucher.validate();
-    if (!validation) { return; }
+    const validation = vm.voucher.validate();
+    if (!validation) { return 0; }
 
     return Vouchers.create(record)
-      .then(function (response) {
+      .then((response) => {
         Notify.success('CASH.TRANSFER.SUCCESS');
         return Receipts.voucher(response.uuid, true);
       })
-      .then(function () {
+      .then(() => {
         return $state.go('^.window', { id : $state.params.id });
       })
       .catch(Notify.handleError);
@@ -46,35 +49,35 @@ function CashTransferModalController(Currencies, Vouchers, Cashboxes, Accounts,
   function prepareVoucherRecord() {
 
     // extract the voucher from the VoucherForm
-    var record = vm.voucher.details;
+    const record = vm.voucher.details;
     record.items = vm.voucher.store.data;
 
     // configure the debits/credits appropriately
 
-    var debit = record.items[0];
+    const debit = record.items[0];
     debit.configure({ debit : vm.amount, account_id : vm.transferAccount.id });
 
-    var credit = record.items[1];
+    const credit = record.items[1];
     credit.configure({ credit : vm.amount, account_id : vm.cashAccount.id });
 
     // format voucher description as needed
     vm.voucher.description('CASH.TRANSFER.DESCRIPTION', {
       amount : vm.amount,
       fromLabel : vm.cashAccount.label,
       toLabel : vm.transferAccount.label,
-      userName : Session.user.display_name
+      userName : Session.user.display_name,
     });
 
     return record;
   }
 
   // this object retains a mapping of the currency ids to their respective accounts.
-  var cashCurrencyMap = {};
+  let cashCurrencyMap = {};
 
   // this function maps the accounts to their respective currencies.
   // { currency_id :  { currency_id, account_id, transfer_account_id } }
   function mapCurrenciesToAccounts(currencies) {
-    return currencies.reduce(function (map, currency) {
+    return currencies.reduce((map, currency) => {
       map[currency.currency_id] = currency;
       return map;
     }, {});
@@ -88,11 +91,11 @@ function CashTransferModalController(Currencies, Vouchers, Cashboxes, Accounts,
 
     // load needed modules
     Currencies.read()
-      .then(function (currencies) {
+      .then((currencies) => {
         vm.currencies = currencies;
         return Cashboxes.read($state.params.id);
       })
-      .then(function (cashbox) {
+      .then((cashbox) => {
         vm.cashbox = cashbox;
         vm.disabledCurrencyIds = Cash.calculateDisabledIds(cashbox, vm.currencies);
 
@@ -108,19 +111,19 @@ function CashTransferModalController(Currencies, Vouchers, Cashboxes, Accounts,
     cashCurrencyMap = mapCurrenciesToAccounts(vm.cashbox.currencies);
 
     // pull the accounts from the cashCurrencyMap
-    var accounts = cashCurrencyMap[selectedCurrencyId];
+    const accounts = cashCurrencyMap[selectedCurrencyId];
 
     // look up the transfer account
     Accounts.read(accounts.transfer_account_id)
-      .then(function (account) {
+      .then((account) => {
         account.hrlabel = Accounts.label(account);
         vm.transferAccount = account;
       })
       .catch(Notify.handleError);
 
     // look up the cash account
     Accounts.read(accounts.account_id)
-      .then(function (account) {
+      .then((account) => {
         account.hrlabel = Accounts.label(account);
         vm.cashAccount = account;
       })

server/config/express.js

@@ -97,7 +97,6 @@ exports.configure = function configure(app) {
 
   // Only allow routes to use /login, /projects, /logout, and /languages if a
   // user session does not exists
-
   app.use((req, res, next) => {
     if (_.isUndefined(req.session.user) && !within(req.path, publicRoutes)) {
       debug(`Rejecting unauthorized access to ${req.path} from ${req.ip}`);

test/client-unit/services/AccountService.spec.js

@@ -4,11 +4,16 @@ describe('AccountService', () => {
 
   let Accounts;
   let $httpBackend;
+  let $timeout;
+  let $verifyNoPendingTasks;
 
   beforeEach(module('bhima.services', 'bhima.mocks', 'angularMoment', 'bhima.constants'));
 
-  beforeEach(inject((_$httpBackend_, AccountService, MockDataService) => {
+  beforeEach(inject((_$httpBackend_, AccountService, MockDataService, _$timeout_, _$verifyNoPendingTasks_) => {
     $httpBackend = _$httpBackend_;
+    $timeout = _$timeout_;
+    $verifyNoPendingTasks = _$verifyNoPendingTasks_;
+
     Accounts = AccountService;
 
     $httpBackend.when('GET', '/accounts/')
@@ -19,17 +24,21 @@ describe('AccountService', () => {
   afterEach(() => {
     $httpBackend.verifyNoOutstandingExpectation();
     $httpBackend.verifyNoOutstandingRequest();
+    $verifyNoPendingTasks('$timeout');
   });
 
 
-  it('#read() will fire an HTTP GET request each time it is called', () => {
+  it('#read() will fire only a single HTTP GET request when called mutliple times in a row', () => {
     const NUM_REQUESTS = 10;
     let count = NUM_REQUESTS;
     while (count--) {
       Accounts.read();
     }
 
+    $timeout.flush();
+
     // this would throw if too many requests were called.
-    expect(() => $httpBackend.flush(NUM_REQUESTS)).not.to.throw();
+    expect(() => $httpBackend.flush(1)).not.to.throw();
+    expect(() => $httpBackend.flush(1)).to.throw();
   });
 });

test/client-unit/services/VoucherForm.spec.js

@@ -6,6 +6,7 @@ describe('VoucherForm', () => {
   let Session;
   let form;
   let Mocks;
+  let $timeout;
 
   beforeEach(module(
     'bhima.services',
@@ -19,10 +20,11 @@ describe('VoucherForm', () => {
     'bhima.mocks'
   ));
 
-  beforeEach(inject((_VoucherForm_, $httpBackend, _SessionService_, _MockDataService_) => {
+  beforeEach(inject((_VoucherForm_, $httpBackend, _SessionService_, _MockDataService_, _$timeout_) => {
     VoucherForm = _VoucherForm_;
     Session = _SessionService_;
     Mocks = _MockDataService_;
+    $timeout = _$timeout_;
 
     // set up the required properties for the session
     Session.create(Mocks.user(), Mocks.enterprise(), Mocks.project());
@@ -37,6 +39,7 @@ describe('VoucherForm', () => {
 
   // make sure $http is clean after tests
   afterEach(() => {
+    $timeout.flush();
     httpBackend.flush();
     httpBackend.verifyNoOutstandingExpectation();
     httpBackend.verifyNoOutstandingRequest();