Add e2e tests for export hosts feature (#5895)

cypress/integration/all/app/hosts.spec.ts

@@ -29,7 +29,6 @@ describe("Hosts flow", () => {
       cy.visit("/hosts/manage");
 
       cy.getAttached(".manage-hosts").within(() => {
-        // cy.getAttached(".manage-hosts__export-btn").click(); // Feature pushed back from 4.13 release
         cy.contains("button", /add hosts/i).click();
       });
       cy.getAttached(".react-tabs").within(() => {
@@ -71,6 +70,20 @@ describe("Hosts flow", () => {
         });
       }
     });
+    it(`exports hosts to CSV`, () => {
+      cy.visit("/hosts/manage");
+      cy.getAttached(".manage-hosts").within(() => {
+        cy.getAttached(".manage-hosts__export-btn").click();
+      });
+      if (Cypress.platform !== "win32") {
+        // windows has issues with downloads location
+        const formattedTime = format(new Date(), "yyyy-MM-dd");
+        const filename = `Hosts ${formattedTime}.csv`;
+        cy.readFile(path.join(Cypress.config("downloadsFolder"), filename), {
+          timeout: 5000,
+        });
+      }
+    });
     it(`hides and shows "Used by" column`, () => {
       cy.visit("/hosts/manage");
       cy.getAttached("thead").within(() =>

frontend/pages/hosts/ManageHostsPage/ManageHostsPage.tsx

@@ -1281,7 +1281,7 @@ const ManageHostsPage = ({
     evt.preventDefault();
 
     const hiddenColumnsStorage = localStorage.getItem("hostHiddenColumns");
-    let currentHiddenColumns;
+    let currentHiddenColumns = [];
     let visibleColumns;
     if (hiddenColumnsStorage) {
       currentHiddenColumns = JSON.parse(hiddenColumnsStorage);