ENGCOM-2534: Allow 3rd party modules to perform actions after totals calculation #17127

Author: Stanislav Idolov

app/code/Magento/Checkout/view/frontend/web/js/model/cart/totals-processor/default.js

@@ -38,7 +38,7 @@ define([
             payload.addressInformation['shipping_carrier_code'] = quote.shippingMethod()['carrier_code'];
         }
 
-        storage.post(
+        return storage.post(
             serviceUrl, JSON.stringify(payload), false
         ).done(function (result) {
             var data = {
@@ -96,7 +96,7 @@ define([
             ) {
                 quote.setTotals(cartCache.get('totals'));
             } else {
-                loadFromServer(address);
+                return loadFromServer(address);
             }
         }
     };

dev/tests/js/jasmine/tests/app/code/Magento/Checkout/frontend/js/model/cart/totals-processor/default.test.js

@@ -106,6 +106,8 @@ define([
         });
 
         it('estimateTotals if data wasn\'t cached and request was successfully sent', function () {
+            var deferral = new $.Deferred();
+
             spyOn(mocks['Magento_Checkout/js/model/cart/cache'], 'isChanged').and.returnValue(true);
             spyOn(mocks['Magento_Customer/js/customer-data'], 'get').and.returnValue(
                 ko.observable({
@@ -117,9 +119,9 @@ define([
                 data.shippingMethodCode = mocks['Magento_Checkout/js/model/quote'].shippingMethod()['method_code'];
                 data.shippingCarrierCode = mocks['Magento_Checkout/js/model/quote'].shippingMethod()['carrier_code'];
 
-                return new $.Deferred().resolve(result);
+                return deferral.resolve(result);
             });
-            expect(defaultProcessor.estimateTotals(address)).toBeUndefined();
+            expect(defaultProcessor.estimateTotals(address)).toBe(deferral);
             expect(mocks['Magento_Checkout/js/model/quote'].setTotals).toHaveBeenCalledWith(totals);
             expect(mocks['Magento_Checkout/js/model/totals'].isLoading.calls.argsFor(0)[0]).toBe(true);
             expect(mocks['Magento_Checkout/js/model/totals'].isLoading.calls.argsFor(1)[0]).toBe(false);
@@ -129,6 +131,8 @@ define([
         });
 
         it('estimateTotals if data wasn\'t cached and request returns error', function () {
+            var deferral = new $.Deferred();
+
             spyOn(mocks['Magento_Checkout/js/model/cart/cache'], 'isChanged').and.returnValue(true);
             spyOn(mocks['Magento_Customer/js/customer-data'], 'get').and.returnValue(
                 ko.observable({
@@ -137,9 +141,9 @@ define([
             );
             spyOn(mocks['Magento_Checkout/js/model/cart/cache'], 'get');
             spyOn(mocks['mage/storage'], 'post').and.callFake(function () {
-                return new $.Deferred().reject('Error Message');
+                return deferral.reject('Error Message');
             });
-            expect(defaultProcessor.estimateTotals(address)).toBeUndefined();
+            expect(defaultProcessor.estimateTotals(address)).toBe(deferral);
             expect(mocks['Magento_Checkout/js/model/totals'].isLoading.calls.argsFor(0)[0]).toBe(true);
             expect(mocks['Magento_Checkout/js/model/totals'].isLoading.calls.argsFor(1)[0]).toBe(false);
             expect(mocks['mage/storage'].post).toHaveBeenCalled();