Testing

Test strategy

See ADR 0002 for the full rationale. Three tiers, each with a distinct role:

Unit tests (Vitest, tests/unit/) — pure functions and isolated business rules only. No DB, no I/O.

Integration tests (Vitest, tests/integration/) — server actions and API route handlers against a real in-memory SQLite DB. Verify post-condition state through a read surface in order of preference: (1) the corresponding GET endpoint, (2) repo read methods, (3) direct DB rows (last resort). Only redirect() and revalidatePath() are mocked.

E2E tests (Playwright, tests/e2e/) — behavior that only manifests in a browser: routing, phase-dependent UI, modals, form interaction, mobile layout. Prefer fewer, high-confidence tests over broad coverage.

Test quality guardrails

  • A test that breaks on an internal rename without a user-visible behavior change is a bad test. Rewrite or delete it.
  • Never assert on call counts of internal helpers.
  • If making a test pass requires reaching into a private, the test is wrong.
  • Factories produce minimal entities; tests override only the fields they care about. If a test sets 12 fields, the factory is wrong.
  • No cross-test state. Each test builds what it needs.

TDD workflow

Every code change must follow red → green → refactor. Do not skip or reorder steps.

  1. Write a failing test that captures the expected behavior.
  2. Run the test and confirm it actually fails (see commands below).
  3. Implement the minimum code to make it pass.
  4. Run the test again and confirm it is green.
  5. Refactor if needed — do not touch the test during refactor.

Exceptions (apply conservatively):

  • Pure UI/layout/styling changes with no behavior change
  • Refactors where existing tests already fully cover the changed code

Running tests

make test                # Run unit and integration tests (Vitest)
make test-e2e            # Run E2E tests (headless)
make test-e2e-headed     # Run E2E tests (headed, for local dev)
make test-e2e-docker     # Run E2E tests against the production Docker image

Warning: E2E tests reset the test database before each run. Do not run against production data.

Tests that send real email (in make test and make test-e2e) are opt-in: they need a local mailpit (start it with make mailpit) and the mail variables set in .env.test.local:

# .env.test.local
MAILPIT_API_URL=http://localhost:8025
SMTP_URL=smtp://localhost:1025
SMTP_FROM='Test <mailer-test@test.example>'

When these are unset (the default on a fresh checkout), the email tests are reported as skipped; when they are set but mailpit is unreachable, the tests fail. CI always sets them (in .github/workflows/ci.yml and .github/workflows/ci-e2e.yml, where mailpit is started from docker-compose.dev.yml so its image pin lives in one place) and the tests fail there if the variables go missing, so they can never be silently skipped in CI.

E2E tests run in their own workflow so that they can be skipped for changes that cannot affect the app — documentation, the landing page, repository prose. Adding a top-level path that the app doesn’t use? Add it to both paths-ignore lists in .github/workflows/ci-e2e.yml.

Running another clone or workspace of this project alongside this one? See Running Multiple Instances for the ports that have to be kept apart.

Install Playwright browsers before first use:

make install-playwright

Run a single E2E spec, or filter by test title with -g:

bun set-env.ts test bun x playwright test tests/e2e/proposals.spec.ts
bun set-env.ts test bun x playwright test tests/e2e/proposals.spec.ts:42   # single test by line
bun set-env.ts test bun x playwright test -g "creates a proposal"          # by title substring

The suite runs as two projects. firefox holds everything and runs in parallel; firefox-globals holds the specs that change site-wide settings — one row every other test reads — and depends on firefox, so it starts only once the parallel bulk is done and has the site to itself. It runs on a single worker, so its specs don’t race each other either. settings.spec.ts is the only member today; add a spec here (via GLOBALS_MUTATING_SPECS in playwright.config.ts) when it mutates a singleton rather than data of its own.

The price of the dependency: a failure anywhere in firefox skips firefox-globals altogether, so those specs report nothing until the bulk is green again. Run them on their own to see where they stand. That also pulls in the whole project they depend on, so pass --no-deps:

bun set-env.ts test bun x playwright test tests/e2e/settings.spec.ts --no-deps

Run against a different environment (e.g. dev database — still resets it):

bun set-env.ts dev bun x playwright test

Release-upgrade tests

Every other tier starts from a database this checkout’s migrations built. A self-hoster’s does not: it was written by an older release and is migrated forward when they pull a new image. tests/integration/release-upgrade.test.ts covers that path — for each stored release it restores that release’s seeded database, lets the repositories migrate it (what starting the app does), and then checks that

  • every migration applied, and the result has the same shape as a fresh database — same columns, foreign keys and indexes;
  • the old release’s data still reads back through the repositories;
  • creating, updating and deleting works for proposals, votes, sessions, rooms, days, RSVPs, comments, guests and the site settings.

It runs in make test like any other integration test; the whole set takes a few seconds. It is deliberately shallow — enough to catch a migration that only fails against real data, or a read path that assumes a shape only new rows have, not an exhaustive replay of every feature.

The fixtures are SQL dumps of a release’s seeded database in tests/fixtures/upgrade/, one per distinct schema rather than per release: a release that ships no migration reaches the same database as the one before it, so it needs no dump of its own. Record one while finalizing the changelog, in the release commit itself (see Releasing a New Version):

make dump-release-db VERSION=v3.5.0

The dump has to come from the release itself — its schema, its seed script. At that point that is the working tree, which the script seeds with the small profile into a scratch database of its own. Recording a version that is already tagged instead checks the tag out into a throwaway git worktree and seeds it there, so a dump taken after the fact still comes from the released code. When the release applies the same migrations as a dump that already exists, no dump is written.

tests/fixtures/upgrade/releases.json says which dump covers which release, so a release without one is on the record instead of just missing:

{ "v3.4.1": "v3.4.0" } // no migrations of its own, v3.4.0's dump covers it

The tests hold that file to the changelog — every released version has to appear in it, so a forgotten make dump-release-db fails make test in the release commit rather than quietly leaving a version untested. They also check the other direction: every dump the file names exists, and every stored dump is named.

Dumps are never edited or regenerated: an old one is a record of what that release actually wrote, and make dump-release-db refuses to overwrite one. When support for upgrading from old versions is dropped, delete those dumps, drop their releases.json entries, and raise oldestSupported to the oldest version still covered.

Testing the Docker image

make test-e2e runs the suite against next build && next start, which is not what we ship. The image runs the standalone build as node server.js, as a different user, with the database, migrations and uploads on a mounted /data volume. make test-e2e-docker runs the same suite against a container built from the working tree, which is the only tier that covers that gap:

make test-e2e-docker                     # build the image, then run the suite against it
IMAGE=schellingboard/schellingboard:v3.1.0 \
  bun set-env.ts test bash scripts/e2e-docker.sh    # test an existing image instead of building

# A subset, same arguments as `playwright test`:
bun set-env.ts test bash scripts/e2e-docker.sh tests/e2e/proposals.spec.ts

It is not part of make precommit — it builds an image and takes a few minutes. The release workflow runs it against the image it is about to publish and refuses to publish if it fails (see Releasing a New Version), so the reason to run it by hand is a change to the Dockerfile, the standalone build, or anything touching paths, uploads or migrations — well before a release rather than at one.

What it does, and why each piece is there:

  • Picks a free port and starts the container on it, then waits for /api/health.
  • Builds through scripts/docker-build.sh, the script make docker-build and the release workflow run too — same build arguments, same :<version> tag, so what gets published is what was tested. (In the release workflow the build comes first and is handed here by name in IMAGE, so the very image that is pushed is the one the suite ran against.) The version is the one scripts/app-version.js prints, which is also what the footer shows.
  • Bind-mounts .e2e-docker/ (gitignored) as /data. Seeding runs on the host, as usual, and writes to the same SQLite file and uploads directory the container reads — so no seeding code has to exist inside the image. The directory is deleted at the start of every run, since a stale database hides exactly the failures this run looks for. Seeding migrates the database first, so what the container’s own migration run covers is that drizzle/ shipped and loads, not applying migrations to an empty database.
  • Runs the container as your own uid (--user), so the files it writes into the bind mount don’t end up owned by the image’s uid 1001 and unremovable. As a consequence /app isn’t writable, so Next’s image optimizer gets a tmpfs for its cache — otherwise every optimized image logs an EACCES.
  • Starts mailpit if it isn’t already running, because once the mail variables are set the email specs fail rather than skip. One it started itself is stopped again afterwards, unless the run failed — then it is left up, since its web UI is where a failing email test is diagnosed.
  • Points SITE_URL and the SMTP host at the container’s view of the host (host.docker.internal), so emails link back to the right port and reach mailpit.

Playwright starts no server of its own here: the script sets E2E_EXTERNAL_SERVER=1 and E2E_PORT, and playwright.config.ts omits its webServer when it sees them.

The container runs in UTC. That is what makes this tier worth having: with next start, the server and the browser share your machine’s timezone, so a component that formats a date in the ambient zone renders identically on both sides and its hydration mismatch stays invisible. In the image it does not. Dates must be formatted in an explicit zone — the event’s — never the process’s.

Flake hunting

A test that fails once in twenty runs is invisible to a normal make test-e2e. scripts/e2e-flake-hunt.sh runs the suite repeatedly and keeps the evidence, so flakes can be ranked by failure rate instead of by whoever noticed one last:

scripts/e2e-flake-hunt.sh                      # 20 runs of the whole suite
scripts/e2e-flake-hunt.sh 5 -- tests/e2e/voting.spec.ts --repeat-each=3
nohup scripts/e2e-flake-hunt.sh 20 > flake-hunt.log 2>&1 &   # overnight

Everything lands in .flake-hunt/<UTC timestamp>/ (gitignored): meta.json (commit, worker count, machine), then one run-NNN/ per iteration holding that run’s results.json (the Playwright JSON report), its console log, and traces of whatever failed. Traces are recorded with --trace=retain-on-failure, so a failure comes with network log, console and per-action DOM snapshots — open one with bun x playwright show-trace <path>.

The app is built and started once for the whole hunt, not per run: a next build per iteration would dominate the runtime, while the part that has to repeat — reseeding the database in globalSetup — still happens once per run. Retries are forced to 0: the hunt wants raw failure rates, not Playwright’s own flake classification.

Two knobs, both environment variables:

  • E2E_WORKERS=N — passed on as --workers. Setting it at or above the core count overloads the CPU deliberately, which makes timing-dependent flakes surface in far fewer runs.
  • HUNT_KEEP_PASSING=0 — shrink green runs’ results.json to their stats block. Only worth it for very long hunts: the report still counts those runs as passes, but their per-test durations are gone, so the duration-outlier section is left looking at the red runs alone.

The hunt ends by aggregating itself. To re-aggregate, or to compare a hunt from before a fix with one from after:

bun scripts/e2e-flake-report.ts .flake-hunt/<ts>
bun scripts/e2e-flake-report.ts .flake-hunt/<before> .flake-hunt/<after>

The report — printed and written to report.md in the last directory given — lists flaky tests (failed in some runs, passed in others) with their failure rate, normalized error signature and the runs whose traces to open; persistent failures separately, since failing every time is a breakage rather than a flake; tests whose p95 duration is within striking distance of their timeout; and failures grouped by signature, which is what reveals that several tests share one root cause.

If the mail variables are set in .env.test.local, start mailpit (make mailpit) before a hunt — otherwise the email specs fail identically in every run and clutter the report as persistent failures.

Flaky tests

Locally the suite retries a failing test once, and a test that then passes still fails the run (failOnFlakyTests). The retry is not leniency, it is evidence: trace: on-first-retry records nothing when nothing is retried, so without it a local flake left an error message and no way to look into it. Now it leaves test-results/<test>-retry1/trace.zip, and the terminal ends with a flaky section naming the test — which also tells you at a glance whether the test is flaky or plain broken, since a broken one fails both attempts. Open the trace with:

bun x playwright show-trace test-results/<test>-retry1/trace.zip

A second local retry would buy only a failure rate out of three, at the price of running every genuinely failing test three times while you work — measuring rates is what Flake hunting is for.

CI is the other way round: it retries twice and stays green, because nobody is watching a run to interrupt, and a suite that goes red on a known flake gets ignored wholesale. So the run records instead of failing:

  • Error annotations — Playwright’s own github reporter annotates every failed attempt with its error message and location, flaky tests included. So a green run can carry red annotations: they are a failed attempt, not a failed run.
  • Warning annotations — scripts/ci-flaky-summary.ts reads the JSON report and emits one ::warning per test Playwright classified as flaky, plus a table in the job summary — the part the reporter cannot do, and the one that survives being scrolled past.
  • The playwright-report artifact (14 days) holds the html report, the JSON report and test-results/ — including the trace of the failed attempt, since trace: on-first-retry records exactly that one. Download it, unzip it and open the trace with bun x playwright show-trace <path>.

A flaky warning is a test that failed for a reason; treat it as a bug to be diagnosed from that trace, not as noise. CI’s retries stay at 2 until the suite is stable — the aim there is to measure flakiness, not to start failing on it.

E2E conventions

  • Imitate human behavior — click visible elements, navigate naturally
  • Use semantic locators (getByRole, getByText, getByLabel), not IDs or CSS classes
  • Never construct URLs with internal IDs or replay raw API payloads
  • Never assert on a global aggregate of shared data — an exact total, “first in the list”. The whole suite shares one database and runs in parallel, so another spec creating a user or editing a profile can move any of them. Assert within data the test created itself, or between two named seeded rows (“Alice sorts above Ahmad”), which stays true however many rows appear around them. Comparing one count against another (fewer after a filter than before) holds only where no row a parallel spec can add moves the two the same way
  • Give anything a test creates a name of its own (E2E Admin User ${uniqueSuffix()}), distinctive enough that no other spec’s search or filter can match it. Take the suffix from tests/e2e/helpers/unique.ts, never a bare Date.now(): workers are separate processes sharing one database, and two of them can land in the same millisecond
  • A cross-test invariant that only a comment states (“no other test votes on this proposal”) is enforced by nothing. Put it in the seed or the fixture where it can be relied on, or write the assertion so it does not need the invariant
  • Nothing a page does in an effect is covered by an assertion the server render already satisfies. toHaveCount(0) on something the markup never contained passes instantly, and a click on a server-rendered control satisfies every actionability check a moment before React attaches its handler — so both come up green while hydration is still pending. Where the behavior under test lives in an effect, wait for that effect’s own result before acting on it: kiosk.spec.ts polls until the kiosk cookie is gone before it navigates on, helpers/user.ts taps the chip again
  • The unattended reminder tick is off (REMINDER_DISPATCH_INTERVAL_MS=0 in .env.test, and in the allowlist scripts/e2e-docker.sh forwards to the container). The seed dates every fixture relative to new Date(), so a live tick would drop unrelated mail into the mailbox the delivery assertions search, and unrelated notifications into the lists the notification tests read — flaky by time of day, and worst in the Docker tier. That variable is the only thing that turns the tick off: unsetting SMTP does not, since a reminder is delivered in the app whether or not it can also be mailed. A test that needs reminders delivered clicks Send due reminders on the ?dev=1 toolbar, which runs one dispatch against the dev clock

Test data

Each E2E run starts from a clean database with 3 events (Alpha/Beta/Gamma) in different phases, plus pre-created proposals, sessions, users, and auth. See tests/reset-database.ts for details. Auth helpers: tests/helpers/auth.ts (login, loginAndGoto).

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