✅ Add real basic integration tests

package.json

@@ -8,11 +8,13 @@
     "lint:js": "eslint --ext .js,.vue,.html calendar datepicker tests docs",
     "lint:sass": "sass-lint -q -v",
     "pretest": "npm run lint",
-    "test": "npm run docs:generate",
+    "test": "npm run unit && npm run integration",
+    "posttest": "npm run docs:generate",
     "start": "npm run docs",
     "docs": "NODE_ENV=dev nuxt -c docs/nuxt.config.js",
     "docs:generate": "nuxt generate -c docs/nuxt.config.js",
-    "unit": "karma start tests/unit/karma.conf.js --single-run"
+    "unit": "karma start tests/unit/karma.conf.js --single-run",
+    "integration": "ava tests/integration"
   },
   "repository": {
     "type": "git",
@@ -37,6 +39,7 @@
   "devDependencies": {
     "@nuxtjs/markdownit": "^1.1.2",
     "@nuxtjs/pwa": "^0.2.1",
+    "ava": "^0.22.0",
     "babel-eslint": "^8.0.0",
     "babel-loader": "^7.1.2",
     "chai": "^4.1.2",

tests/integration/calendar.js

@@ -0,0 +1,32 @@
+import test from 'ava';
+import puppeteer from 'puppeteer';
+import server from '../test-server';
+
+// Set up a new server for each test
+test.cb.beforeEach(t => {
+  t.context.port = ~~(Math.random() * 1000) + 8000; // eslint-disable-line no-param-reassign
+  t.context[`server-${t.context.port}`] = server.listen(t.context.port, 'localhost', () => { // eslint-disable-line no-param-reassign
+    t.end();
+  });
+});
+
+// Break down server after each test
+test.afterEach.cb(t => {
+  t.context[`server-${t.context.port}`].close();
+  t.end();
+});
+
+test('Today has focus', async t => {
+  const browser = await puppeteer.launch();
+  const page = await browser.newPage();
+  await page.goto(`http://localhost:${t.context.port}`);
+  await page.press('Tab');
+
+  const active = await page.evaluate(() => {
+    return document.activeElement;
+  });
+
+  await browser.close();
+
+  t.is(active._prevClass, 'calendar__link');
+});