headplane/docs/development/testing.md

Testing

Headplane has two test suites. Both run with Vitest.

Command	What it runs	Needs
pnpm test:unit	tests/unit, in about a second	Node
pnpm test:integration	tests/integration, against real Headscale and nodes	Docker
pnpm harness up	A seeded tailnet that keeps running until you stop it	Docker

Every test should be able to fail because of a regression you can name. Tests that only restate the code, or check that something exists, get deleted. See AGENTS.md for the full rules.

Unit tests

Unit tests cover the logic that doesn't need Headscale: config loading, auth sessions, roles, parsing, and form schemas. They use real implementations wherever they're cheap, such as the auth service on an in-memory SQLite database. Anything that talks to Headscale runs against the real thing in the integration tests instead of a fake or a stubbed client.

Integration tests

Integration tests run against real containers through the harness in tests/harness. It starts disposable tailnets built on Testcontainers, and works with Docker, Podman, Colima, and OrbStack.

import { createTailnet } from "../../harness/tailnet";

test("peers see a renamed machine", async () => {
  await using tailnet = await createTailnet({ policy: allowAll });
  const web = await tailnet.node({ name: "web", user: "alice@", ssh: true });
  const db = await tailnet.node({ name: "db", user: "alice@" });

  const app = await tailnet.headplane();
  // ...rename web through Headplane, then read db's `tailscale status`
});

Each tailnet has its own Docker network, a Headscale served over HTTPS with a generated certificate, and Tailscale nodes that join with pre-auth keys. A node can advertise routes, an exit node, tags, or SSH. node.down() and node.up() switch it off and on. tailnet.pendingNode() starts one that waits for interactive registration.

tailnet.headplane() runs Headplane in-process against the tailnet, built from the same app context production uses. Sign in as any role and call a route the way React Router would:

import { action } from "~/routes/settings/auth-keys/overview";

import { statusOf } from "../../support/app";

test("a viewer can't create a tag-only key", async () => {
  await using tailnet = await createTailnet();
  const app = await tailnet.headplane();
  const { cookie } = await app.signIn("viewer");

  const result = await app.call(action, "/settings/auth-keys", {
    as: cookie,
    form: { intent: "create", tags: "tag:prod", expiry: "90" },
  });

  expect(statusOf(result)).toBe(403);
});

tests/integration/headscale/contract.test.ts describes what Headplane relies on from Headscale's API, including the quirks of each version, and checks it through Headplane's own client. permissions.test.ts calls every route as each role, so a new route is covered as soon as it's added.

The supported Headscale versions live in tests/harness/versions.ts. Locally, integration tests run against the latest one. Set HP_HEADSCALE_VERSIONS=all (as CI does) or a comma-separated list to run others.

Scenarios

A scenario is a seeded tailnet described as data: users, machines, routes, a policy, and DNS settings. They live in tests/harness/scenarios.

pnpm harness list
pnpm harness up homelab --headplane
pnpm harness up fleet --version 0.28.0   # HP_FLEET_SIZE=200 for more machines

up prints the Headscale URL and API key and keeps everything running until you press Ctrl-C. With --headplane it also starts the dev server against it on port 3001. Use scenarios to try a change by hand, to reproduce a setup from a bug report, and to take the screenshots in these docs.