[Tabs] Fix "Eager Load Tabs" option (#4371)

* If eager load is checked, tabs are pre-fetched and kept alive.
* If eager load is not checked, tabs are not pre-fetched, and are not kept alive

src/plugins/tabs/components/tabs.vue

@@ -152,6 +152,10 @@ export default {
     },
     methods: {
         addTabToLoaded(tab) {
+            if (!this.internalDomainObject.keep_alive) {
+                this.loadedTabs = {};
+            }
+
             this.loadedTabs[tab.keyString] = true;
         },
         setCurrentTabByIndex(index) {

src/plugins/tabs/pluginSpec.js

@@ -173,9 +173,34 @@ describe('the plugin', function () {
             return Vue.nextTick();
         });
 
+        afterEach(() => {
+            count = 0;
+        });
+
         it ('renders a tab for each item', () => {
             let tabEls = element.querySelectorAll('.js-tab');
+
             expect(tabEls.length).toEqual(2);
         });
+
+        describe('with domainObject.keep_alive set to', () => {
+
+            it ('true, will keep all views loaded, regardless of current tab view', () => {
+                let tabViewEls = element.querySelectorAll('.c-tabs-view__object');
+
+                expect(tabViewEls.length).toEqual(2);
+            });
+
+            it ('false, will only keep the current tab view loaded', async () => {
+                testViewObject.keep_alive = false;
+
+                await Vue.nextTick();
+
+                let tabViewEls = element.querySelectorAll('.c-tabs-view__object');
+
+                expect(tabViewEls.length).toEqual(1);
+            });
+
+        });
     });
 });