WIP: Move test to cypress.io

This is mostly just a PoC to see if our CI infrastructure is able to run
cypress.io tests.

Changing language currently triggers a "500 Parse Error" in cypress,
which needs to be fixed in Cockpit.

cypress/integration/application.js

@@ -0,0 +1,54 @@
+// Use this for skipping the login page, i. e. all tests which do not test the login page itself
+const visit_opts = { auth: { username: 'admin', password: 'foobar' } };
+
+describe('Application', () => {
+    beforeEach('start VM', function () {
+        cy.task('startVM').then(url => Cypress.config('baseUrl', url));
+
+        // Programmatically enable the "Reuse my password for privileged tasks" option
+        cy.server({
+            onAnyRequest: function (route, proxy) {
+                proxy.xhr.setRequestHeader('X-Authorize',  'password');
+            }
+        });
+    });
+
+    afterEach('stop VM', function() {
+        cy.task('stopVM');
+    });
+
+    it('basic functionality', function () {
+        // cypress doesn't handle frames, so go to specific frame
+        cy.visit('/cockpit/@localhost/starter-kit/index.html', visit_opts)
+        // verify expected heading
+        cy.get('.container-fluid h2').should('contain', 'Starter Kit');
+        // verify expected host name
+        cy.task('runVM', 'cat /etc/hostname').then(out => {
+            cy.get('.container-fluid p').should('contain', 'Running on ' + out.trim());
+        });
+    });
+
+    it('test with German translations', function() {
+        cy.visit('/', visit_opts);
+
+        // change language in menu
+        cy.get('#content-user-name').click();
+        cy.get('.display-language-menu a').click();
+        cy.get('#display-language select').select('de-de');
+
+        // HACK: language switching in Chrome not working in current session (Cockpit issue #8160)
+        cy.on('uncaught:exception', (err, runnable) => {
+            cy.log("Uncaught exception:", err);
+            return false;
+        });
+
+        // menu label (from manifest) should be translated
+        cy.get('#display-language-select-button').click();
+        cy.get("#host-apps a[href='/starter-kit']").should('contain', 'Bausatz');
+
+        // page label (from js) should be translated
+        cy.visit('/cockpit/@localhost/starter-kit/index.html');
+        cy.get('.container-fluid p').should('contain', 'Läuft auf');
+    });
+
+})

cypress/plugins/index.js

@@ -0,0 +1,69 @@
+const child_process = require("child_process");
+
+var vm_proc, ssh_args, cockpit_url;
+
+// poor man's polling implementation
+function waitpid(pid) {
+    return new Promise((resolve, reject) => {
+        function check() {
+            try {
+                process.kill(pid);
+                // succeeds → process still exists, poll again
+                setTimeout(check, 50);
+            } catch(e) {
+                // ESRCH → process is gone
+                if (e.code == "ESRCH")
+                    resolve(null);
+                else
+                    throw e;
+            }
+        }
+
+        check();
+    });
+}
+
+module.exports = (on, config) => {
+    on("task", {
+        startVM: image => {
+            if (!image)
+                image = process.env.TEST_OS || "fedora-29";
+            // already running? happens when cypress restarts the test after visiting a baseUrl the first time
+            if (vm_proc)
+                return cockpit_url;
+
+            // no, start a new VM
+            return new Promise((resolve, reject) => {
+                let proc = child_process.spawn("bots/machine/testvm.py", [image],
+                                               { stdio: ["pipe", "pipe", "inherit"] });
+                let buf = "";
+                vm_proc = proc.pid;
+                proc.stdout.on("data", data => {
+                    buf += data.toString();
+                    if (buf.indexOf("\nRUNNING\n") > 0) {
+                        let lines = buf.split("\n");
+                        ssh_args = lines[0].split(" ").slice(1);
+                        cockpit_url = lines[1];
+                        resolve(cockpit_url);
+                    }
+                });
+                proc.on("error", err => reject (err));
+            });
+        },
+
+        stopVM: () => {
+            process.kill(vm_proc);
+            let p = waitpid(vm_proc);
+            p.then(() => { vm_proc = null; });
+            return p;
+        },
+
+        runVM: command => {
+            res = child_process.spawnSync("ssh", ssh_args.concat(command),
+                                          { stdio: ["pipe", "pipe", "inherit"], encoding: "UTF-8" });
+            if (res.status)
+                throw new Error(`Command "${command} failed with code ${res.status}`);
+            return res.stdout;
+        }
+    });
+}