Keep test helpers out of the shipped binary (closes #506)

The test helpers lived in ordinary `testing.go` files inside the config, database, middleware and session packages, so they were built into the binary and the shared `test-support` lint rule could not see them. The four files are gone: the session's helpers move into its own `_test.go` file, and the rest into `configtest`, `databasetest` and `middlewaretest`, which the `depguard` deny list now names, so a non-test file importing them fails lint. The test-support packages build through the production constructors.

Judgement call: the session, the middleware and the webhook database manager now take the plain logger they log through, which the application wiring provides.
Judgement call: two idle-expiry tests move the stored timestamps back instead of advancing a fake clock.

Model: opus-5-5

internal/middleware/middleware_test.go

@@ -14,36 +14,34 @@ import (
 
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
+	"go.uber.org/fx/fxtest"
 	"sneak.berlin/go/webhooker/internal/config"
+	"sneak.berlin/go/webhooker/internal/database"
 	"sneak.berlin/go/webhooker/internal/middleware"
+	"sneak.berlin/go/webhooker/internal/middleware/middlewaretest"
 	"sneak.berlin/go/webhooker/internal/session"
 )
 
 const testKeySize = 32
 
 // testMiddleware creates a Middleware with minimal dependencies
-// for testing. It uses a real session.Session backed by an
-// in-memory cookie store.
+// for testing. It uses a real session.Session.
 func testMiddleware(
 	t *testing.T,
 	env string,
 ) (*middleware.Middleware, *session.Session) {
 	t.Helper()
 
-	m, s, _ := testMiddlewareWithSessionClock(t, env, 0, nil)
-
-	return m, s
+	return testMiddlewareWithIdleTimeout(t, env, 0)
 }
 
-// testMiddlewareWithSessionClock is testMiddleware with a
-// configurable session idle timeout and a manually advanced clock,
-// for the session-expiry tests. A nil clock uses the real one.
-func testMiddlewareWithSessionClock(
+// testMiddlewareWithIdleTimeout is testMiddleware with a
+// configurable session idle timeout, for the session-expiry tests.
+func testMiddlewareWithIdleTimeout(
 	t *testing.T,
 	env string,
 	idleTimeout time.Duration,
-	clock *fakeClock,
-) (*middleware.Middleware, *session.Session, *fakeClock) {
+) (*middleware.Middleware, *session.Session) {
 	t.Helper()
 
 	log := slog.New(slog.NewTextHandler(
@@ -56,59 +54,44 @@ func testMiddlewareWithSessionClock(
 		SessionIdleTimeout: idleTimeout,
 	}
 
-	sessManager := newTestSessionManager(cfg, log, clock)
+	sessManager := newTestSessionManager(t, cfg)
 
-	m := middleware.NewForTest(log, cfg, sessManager)
+	m := middlewaretest.New(t, log, cfg, sessManager)
 
-	return m, sessManager, clock
+	return m, sessManager
 }
 
 // newTestSessionManager builds the real session.Session the
-// middleware tests run against: an in-memory cookie store with a
-// known key, and optionally a manually advanced clock.
+// middleware tests run against, through session.New, with its key
+// in a main database of its own.
 func newTestSessionManager(
+	t *testing.T,
 	cfg *config.Config,
-	log *slog.Logger,
-	clock *fakeClock,
 ) *session.Session {
-	key := make([]byte, testKeySize)
+	t.Helper()
 
-	for i := range key {
-		key[i] = byte(i)
-	}
+	discard := slog.New(slog.DiscardHandler)
 
-	store := session.NewStore(key)
+	db, err := database.Open(t.TempDir(), discard)
+	require.NoError(t, err)
 
-	var now func() time.Time
+	t.Cleanup(func() { _ = db.Close() })
 
-	if clock != nil {
-		now = clock.Now
-	}
+	lc := fxtest.NewLifecycle(t)
 
-	return session.NewForTest(store, cfg, log, key, now)
-}
+	sessManager, err := session.New(lc, session.Params{
+		Config:   cfg,
+		Database: db,
+		Logger:   discard,
+	})
+	require.NoError(t, err)
 
-// fakeClock is a manually advanced clock, so session expiry can be
-// tested without sleeping.
-type fakeClock struct {
-	t time.Time
-}
+	// The start hook reads the key from db and builds the cookie
+	// store.
+	lc.RequireStart()
+	t.Cleanup(lc.RequireStop)
 
-func (c *fakeClock) Now() time.Time {
-	return c.t
-}
-
-func (c *fakeClock) Advance(d time.Duration) {
-	c.t = c.t.Add(d)
-}
-
-// newFakeClock returns a clock started at a fixed instant.
-func newFakeClock() *fakeClock {
-	return &fakeClock{
-		t: time.Date(
-			2026, time.January, 2, 3, 4, 5, 0, time.UTC,
-		),
-	}
+	return sessManager
 }
 
 // --- Logging Middleware Tests ---
@@ -583,6 +566,40 @@ func sessionCookies(
 	return out
 }
 
+// aged re-issues the session cookie in cookies with both of its
+// timestamps moved back by d: the cookie as it stands once d has
+// passed, so session expiry can be tested without sleeping.
+func aged(
+	t *testing.T,
+	sessManager *session.Session,
+	cookies []*http.Cookie,
+	d time.Duration,
+) []*http.Cookie {
+	t.Helper()
+
+	req := httptest.NewRequestWithContext(
+		context.Background(), http.MethodGet, "/", nil)
+
+	for _, c := range cookies {
+		req.AddCookie(c)
+	}
+
+	sess, err := sessManager.Get(req)
+	require.NoError(t, err)
+
+	for _, key := range []string{session.CreatedAtKey, session.LastSeenKey} {
+		at, ok := sess.Values[key].(int64)
+		require.True(t, ok, "the session has no %s", key)
+
+		sess.Values[key] = at - int64(d/time.Second)
+	}
+
+	w := httptest.NewRecorder()
+	require.NoError(t, sessManager.Save(req, w, sess))
+
+	return sessionCookies(w)
+}
+
 func TestRequireAuth_IdleExpiredSession_RedirectsToLogin(
 	t *testing.T,
 ) {
@@ -590,13 +607,11 @@ func TestRequireAuth_IdleExpiredSession_RedirectsToLogin(
 
 	idle := time.Hour
 
-	m, sessManager, clock := testMiddlewareWithSessionClock(
-		t, config.EnvironmentDev, idle, newFakeClock(),
+	m, sessManager := testMiddlewareWithIdleTimeout(
+		t, config.EnvironmentDev, idle,
 	)
 
-	cookies := loginCookies(t, sessManager)
-
-	clock.Advance(idle)
+	cookies := aged(t, sessManager, loginCookies(t, sessManager), idle)
 
 	called, w := runAuthed(t, m, cookies)
 
@@ -621,14 +636,12 @@ func TestRequireAuth_RefreshesIdleDeadlineOnActivity(
 
 	idle := time.Hour
 
-	m, sessManager, clock := testMiddlewareWithSessionClock(
-		t, config.EnvironmentDev, idle, newFakeClock(),
+	m, sessManager := testMiddlewareWithIdleTimeout(
+		t, config.EnvironmentDev, idle,
 	)
 
-	cookies := loginCookies(t, sessManager)
-
 	// Activity halfway through the idle window.
-	clock.Advance(idle / 2)
+	cookies := aged(t, sessManager, loginCookies(t, sessManager), idle/2)
 
 	called, w := runAuthed(t, m, cookies)
 	require.True(t, called, "handler should run while valid")
@@ -640,16 +653,22 @@ func TestRequireAuth_RefreshesIdleDeadlineOnActivity(
 	)
 
 	// Past the original deadline. The refreshed cookie is still
-	// good; the original one is not.
-	clock.Advance(idle - time.Second)
+	// good; the original one is not. A minute short of the idle
+	// window leaves room for the real clock, which the session
+	// reads, to tick on while the test runs.
+	later := idle - time.Minute
 
-	calledRefreshed, _ := runAuthed(t, m, refreshed)
+	calledRefreshed, _ := runAuthed(
+		t, m, aged(t, sessManager, refreshed, later),
+	)
 	assert.True(
 		t, calledRefreshed,
 		"refreshed session should outlive the original deadline",
 	)
 
-	calledStale, staleW := runAuthed(t, m, cookies)
+	calledStale, staleW := runAuthed(
+		t, m, aged(t, sessManager, cookies, later),
+	)
 	assert.False(
 		t, calledStale,
 		"the pre-refresh cookie carries the old idle deadline",
@@ -662,8 +681,8 @@ func TestRequireAuth_UnauthenticatedRequestDoesNotRefresh(
 ) {
 	t.Parallel()
 
-	m, sessManager, _ := testMiddlewareWithSessionClock(
-		t, config.EnvironmentDev, time.Hour, newFakeClock(),
+	m, sessManager := testMiddlewareWithIdleTimeout(
+		t, config.EnvironmentDev, time.Hour,
 	)
 
 	// A session cookie that exists but was never authenticated.
@@ -924,12 +943,9 @@ func metricsAuthMiddleware(
 		MetricsPassword: "secret",
 	}
 
-	key := make([]byte, testKeySize)
-	store := session.NewStore(key)
-
-	sessManager := session.NewForTest(store, cfg, log, key, nil)
-
-	return middleware.NewForTest(log, cfg, sessManager)
+	return middlewaretest.New(
+		t, log, cfg, newTestSessionManager(t, cfg),
+	)
 }
 
 // runMetricsAuthRequest sends a GET /metrics request with the