Integration tests using spectron (#410)

Signed-off-by: Jari Kolehmainen <jari.kolehmainen@gmail.com>

spec/integration/helpers/utils.ts

@@ -0,0 +1,34 @@
+import { Application } from "spectron";
+
+let appPath = ""
+switch(process.platform) {
+case "win32":
+  appPath = "./dist/win-unpacked/Lens.exe"
+  break
+case "linux":
+  appPath = "./dist/linux-unpacked/kontena-lens"
+  break
+case "darwin":
+  appPath = "./dist/mac/LensDev.app/Contents/MacOS/LensDev"
+  break
+}
+
+export function setup() {
+  return new Application({
+    // path to electron app
+    args: [],
+    path: appPath,
+    startTimeout: 30000,
+    waitTimeout: 30000,
+  })
+}
+
+export async function tearDown(app: Application) {
+  const pid = app.mainProcess.pid
+  await app.stop()
+  try {
+    process.kill(pid, 0);
+  } catch(e) {
+    return
+  }
+}