Let ircserver and db tests pass under heavy host load (closes #265)

testTimeout, the limit on every read and wait in the ircserver tests,
goes from 5 to 30 seconds. A passing test never reaches it.

TestQuietClientNotAnsweringPingIsClosed uses a 4 second ping interval,
and measures its upper bound from the end of registration. The bound
leaves 2.7 seconds for scheduling delay, and is a second before the
close a two-interval read deadline would make. The lower bound, from
the client's last line, is unchanged.

The cancelled-query tests in internal/db run the endless query for 2
seconds instead of 100 ms. A context that ends before the statement
starts interrupts nothing, so the pool kept its connection.

Model: opus-5-5

README.md

@@ -168,10 +168,8 @@ either.
 - Request bodies for `POST /api/v1/session`, `POST /api/v1/login` and
   `POST /api/v1/messages` are limited to `MAX_MESSAGE_SIZE` bytes (default
   `4096`). A larger body gets `400` `invalid request body`.
-- `GET /api/v1/server` and `GET /.well-known/healthcheck.json` answer a request
+- The server allows cross-origin requests from any origin, with credentials. The
-  from any origin with `Access-Control-Allow-Origin: *`. Every other route sends
+  cookie is `SameSite=Strict`, so a browser sends it only from the same site.
-  no `Access-Control-Allow-*` header, so a page on another origin cannot read
-  its responses.
 
 ### The auth cookie
 
@@ -1895,14 +1893,14 @@ The IRC listener has no TLS.
   seconds. A request still running after 60 seconds is cancelled, and the
   connection closes without a response. Headers may be up to 1 MiB.
 - A long poll waits at most 30 seconds.
-- Every response to a well-formed request carries a `Content-Security-Policy`
+- Every response to a well-formed request, except to a cross-origin preflight,
-  header:
+  carries a `Content-Security-Policy` header:
   `default-src 'self'; script-src 'self'; style-src 'self'; connect-src 'self'; img-src 'self'; font-src 'self'; object-src 'none'; frame-ancestors 'none'; base-uri 'self'; form-action 'self'`.
   The web client works within it.
-- `GET /api/v1/server` and `GET /.well-known/healthcheck.json` answer a request
+- Cross-origin requests are allowed from any origin, with credentials. The
-  from any origin with `Access-Control-Allow-Origin: *`. Every other route sends
+  allowed methods are `GET`, `POST`, `PUT`, `DELETE` and `OPTIONS`. The allowed
-  no `Access-Control-Allow-*` header, so a page on another origin cannot read
+  request headers are `Accept`, `Content-Type` and `X-CSRF-Token`. The cookie's
-  its responses.
+  `SameSite=Strict` still keeps it to the same site.
 
 ### Logging
 

internal/config/config.go

@@ -36,9 +36,9 @@ Type /help for available commands.`
 const DefaultDBURL = "file:///var/lib/neoirc/state.db" +
 	"?_pragma=journal_mode(WAL)&_pragma=busy_timeout(5000)"
 
-// DefaultTrustedProxies is TRUSTED_PROXIES when it is not set: the
+// defaultTrustedProxies is TRUSTED_PROXIES when it is not set: the
 // private address ranges of RFC 1918.
-const DefaultTrustedProxies = "10.0.0.0/8,172.16.0.0/12,192.168.0.0/16"
+const defaultTrustedProxies = "10.0.0.0/8,172.16.0.0/12,192.168.0.0/16"
 
 var errOutOfRange = errors.New("setting out of range")
 
@@ -117,7 +117,7 @@ func New(
 	viper.SetDefault("LOGIN_RATE_LIMIT", "1")
 	viper.SetDefault("LOGIN_RATE_BURST", "5")
 	viper.SetDefault("IRC_LISTEN_ADDR", ":6667")
-	viper.SetDefault("TRUSTED_PROXIES", DefaultTrustedProxies)
+	viper.SetDefault("TRUSTED_PROXIES", defaultTrustedProxies)
 
 	err := viper.ReadInConfig()
 	if err != nil {
@@ -219,7 +219,9 @@ func parseStringAllowEmptyEnv(key string, value *string) error {
 	return parseString(key, value)
 }
 
-// parseTrustedProxies sets *value to the addresses in TRUSTED_PROXIES.
+// parseTrustedProxies sets *value to the addresses in TRUSTED_PROXIES, a
+// comma-separated list of networks such as 10.0.0.0/8 and single
+// addresses such as 192.0.2.1. The empty string trusts nothing.
 func parseTrustedProxies(value **netipx.IPSet) error {
 	var raw string
 
@@ -228,7 +230,18 @@ func parseTrustedProxies(value **netipx.IPSet) error {
 		return err
 	}
 
-	ipSet, err := ParseTrustedProxies(raw)
+	var builder netipx.IPSetBuilder
+
+	if strings.TrimSpace(raw) != "" {
+		for entry := range strings.SplitSeq(raw, ",") {
+			err = addTrustedProxy(&builder, strings.TrimSpace(entry))
+			if err != nil {
+				return fmt.Errorf("cannot parse TRUSTED_PROXIES: %w", err)
+			}
+		}
+	}
+
+	ipSet, err := builder.IPSet()
 	if err != nil {
 		return fmt.Errorf("cannot parse TRUSTED_PROXIES: %w", err)
 	}
@@ -238,25 +251,6 @@ func parseTrustedProxies(value **netipx.IPSet) error {
 	return nil
 }
 
-// ParseTrustedProxies returns the addresses in list, which has the form
-// of TRUSTED_PROXIES: a comma-separated list of networks such as
-// 10.0.0.0/8 and single addresses such as 192.0.2.1. The empty string
-// trusts nothing.
-func ParseTrustedProxies(list string) (*netipx.IPSet, error) {
-	var builder netipx.IPSetBuilder
-
-	if strings.TrimSpace(list) != "" {
-		for entry := range strings.SplitSeq(list, ",") {
-			err := addTrustedProxy(&builder, strings.TrimSpace(entry))
-			if err != nil {
-				return nil, err
-			}
-		}
-	}
-
-	return builder.IPSet()
-}
-
 // addTrustedProxy adds entry, a network with a slash or a single
 // address, to builder. An IPv4 address written in IPv6 form, such as
 // ::ffff:192.0.2.1, is added as IPv4. A network in that form and an

internal/db/auth.go

@@ -22,7 +22,7 @@ func (database *Database) SetPassword(
 	password string,
 ) error {
 	hash, err := bcrypt.GenerateFromPassword(
-		[]byte(password), database.passwordCost,
+		[]byte(password), bcrypt.DefaultCost,
 	)
 	if err != nil {
 		return fmt.Errorf("hash password: %w", err)

internal/db/db.go

@@ -15,7 +15,6 @@ import (
 	"strings"
 
 	"go.uber.org/fx"
-	"golang.org/x/crypto/bcrypt"
 	"sneak.berlin/go/neoirc/internal/config"
 	"sneak.berlin/go/neoirc/internal/logger"
 
@@ -40,19 +39,13 @@ type Params struct {
 
 	Logger *logger.Logger
 	Config *config.Config
-
-	// PasswordCost is the bcrypt cost at which SetPassword hashes
-	// a password. The server leaves it unset, which means
-	// bcrypt.DefaultCost. Tests set a lower cost to save time.
-	PasswordCost int `optional:"true"`
 }
 
 // Database manages the SQLite connection and migrations.
 type Database struct {
-	conn         *sql.DB
+	conn   *sql.DB
-	log          *slog.Logger
+	log    *slog.Logger
-	params       *Params
+	params *Params
-	passwordCost int
 }
 
 // New creates a new Database and registers lifecycle hooks.
@@ -60,15 +53,9 @@ func New(
 	lifecycle fx.Lifecycle,
 	params Params,
 ) (*Database, error) {
-	passwordCost := params.PasswordCost
-	if passwordCost == 0 {
-		passwordCost = bcrypt.DefaultCost
-	}
-
 	database := &Database{ //nolint:exhaustruct // conn set in OnStart
-		params:       &params,
+		params: &params,
-		log:          params.Logger.Get(),
+		log:    params.Logger.Get(),
-		passwordCost: passwordCost,
 	}
 
 	database.log.Info("Database instantiated")

internal/db/db_test.go

@@ -10,7 +10,6 @@ import (
 	"time"
 
 	"go.uber.org/fx/fxtest"
-	"golang.org/x/crypto/bcrypt"
 	"sneak.berlin/go/neoirc/internal/config"
 	"sneak.berlin/go/neoirc/internal/db"
 	"sneak.berlin/go/neoirc/internal/dbtest"
@@ -241,85 +240,6 @@ func TestDBURLSettingForeignKeysFailsStartup(t *testing.T) {
 	}
 }
 
-// TestPasswordCost checks the bcrypt cost of the hash that SetPassword
-// stores: bcrypt.DefaultCost when db.Params leaves PasswordCost unset,
-// as the server does, and PasswordCost when it is set.
-func TestPasswordCost(t *testing.T) {
-	t.Parallel()
-
-	tests := []struct {
-		name         string
-		passwordCost int
-		wantCost     int
-	}{
-		{name: "unset", wantCost: bcrypt.DefaultCost},
-		{
-			name:         "bcrypt.MinCost",
-			passwordCost: bcrypt.MinCost,
-			wantCost:     bcrypt.MinCost,
-		},
-	}
-
-	for _, test := range tests {
-		t.Run(test.name, func(t *testing.T) {
-			t.Parallel()
-
-			lifecycle := fxtest.NewLifecycle(t)
-
-			log, err := logger.New(lifecycle, logger.Params{
-				Globals: &globals.Globals{},
-			})
-			if err != nil {
-				t.Fatal(err)
-			}
-
-			database, err := db.New(lifecycle, db.Params{
-				Logger:       log,
-				Config:       &config.Config{DBURL: dbtest.NewURL(t)},
-				PasswordCost: test.passwordCost,
-			})
-			if err != nil {
-				t.Fatal(err)
-			}
-
-			lifecycle.RequireStart()
-			t.Cleanup(lifecycle.RequireStop)
-
-			sessionID, _, _, err := database.CreateSession(
-				t.Context(), "costuser", "", "", "",
-			)
-			if err != nil {
-				t.Fatal(err)
-			}
-
-			err = database.SetPassword(t.Context(), sessionID, "password123")
-			if err != nil {
-				t.Fatal(err)
-			}
-
-			var hash string
-
-			err = database.GetDB().QueryRowContext(
-				t.Context(),
-				"SELECT password_hash FROM sessions WHERE id = ?",
-				sessionID,
-			).Scan(&hash)
-			if err != nil {
-				t.Fatal(err)
-			}
-
-			cost, err := bcrypt.Cost([]byte(hash))
-			if err != nil {
-				t.Fatal(err)
-			}
-
-			if cost != test.wantCost {
-				t.Errorf("cost = %d, want %d", cost, test.wantCost)
-			}
-		})
-	}
-}
-
 // startDatabase starts a Database for dbURL the way the server does.
 // It returns the error that stopped it from starting, if any.
 func startDatabase(t *testing.T, dbURL string) (*db.Database, error) {

internal/db/export_test.go

@@ -8,12 +8,10 @@ import (
 	"testing"
 	"time"
 
-	"golang.org/x/crypto/bcrypt"
 	"sneak.berlin/go/neoirc/internal/dbtest"
 )
 
-// NewTestDatabase creates an in-memory database for testing. It
+// NewTestDatabase creates an in-memory database for testing.
-// hashes passwords at bcrypt.MinCost.
 func NewTestDatabase(tb testing.TB) (*Database, error) {
 	tb.Helper()
 
@@ -25,9 +23,8 @@ func NewTestDatabase(tb testing.TB) (*Database, error) {
 	}
 
 	database := &Database{ //nolint:exhaustruct // test helper, params not needed
-		conn:         conn,
+		conn: conn,
-		log:          slog.Default(),
+		log:  slog.Default(),
-		passwordCost: bcrypt.MinCost,
 	}
 
 	err = database.runMigrations(context.Background())

internal/handlers/api_test.go

@@ -145,46 +145,34 @@ type testServer struct {
 	handlers   *handlers.Handlers
 }
 
-const (
+// viperMu makes tests start their servers one at a time,
-	// maxMessageSize is MAX_MESSAGE_SIZE on every test server, the
+// because config.New writes the global viper instance and
-	// setting's default.
+// the server reads it as it starts.
-	maxMessageSize = 4096
+//
-
+//nolint:gochecknoglobals // guards a global, so must be one
-	// loginRateLimit is LOGIN_RATE_LIMIT on every test server, the
+var viperMu sync.Mutex
-	// setting's default.
-	loginRateLimit = 1
-
-	// loginRateBurst is LOGIN_RATE_BURST on every test server, the
-	// setting's default.
-	loginRateBurst = 5
-)
 
 func newTestServer(
 	t *testing.T,
 ) *testServer {
 	t.Helper()
 
-	return newTestServerWith(t, 0, "", "", config.DefaultTrustedProxies)
+	return newTestServerWith(t, 0, "", "")
 }
 
 func newTestServerWith(
 	t *testing.T,
 	hashcashBits int,
-	operName, operPassword, trustedProxies string,
+	operName, operPassword string,
 ) *testServer {
 	t.Helper()
 
+	viperMu.Lock()
+	defer viperMu.Unlock()
+
 	dbURL := dbtest.NewURL(t)
 	copyTemplateDB(t, dbURL)
 
-	trusted, err := config.ParseTrustedProxies(trustedProxies)
-	if err != nil {
-		t.Fatalf("parse trusted proxies: %v", err)
-	}
-
-	// Each duration setting defaults to 30 days.
-	const thirtyDays = "720h"
-
 	var (
 		srv      *server.Server
 		brk      *broker.Broker
@@ -196,25 +184,31 @@ func newTestServerWith(
 		fx.Provide(
 			newTestGlobals,
 			logger.New,
-			// Built here rather than by config.New, which writes
+			func(
-			// the global viper instance, so servers start in
+				lifecycle fx.Lifecycle,
-			// parallel.
+				globs *globals.Globals,
-			func() *config.Config {
+				log *logger.Logger,
-				return &config.Config{
+			) (*config.Config, error) {
-					DBURL: dbURL,
+				cfg, err := config.New(
-					// One line: each line is a database write per new session.
+					lifecycle, config.Params{ //nolint:exhaustruct
-					MOTD:               "neoirc test server",
+						Globals: globs, Logger: log,
-					MaxMessageSize:     maxMessageSize,
+					},
-					HashcashBits:       hashcashBits,
+				)
-					OperName:           operName,
+				if err != nil {
-					OperPassword:       operPassword,
+					return nil, fmt.Errorf(
-					MessageMaxAge:      thirtyDays,
+						"test config: %w", err,
-					QueueMaxAge:        thirtyDays,
+					)
-					SessionIdleTimeout: thirtyDays,
-					LoginRateLimit:     loginRateLimit,
-					LoginRateBurst:     loginRateBurst,
-					TrustedProxies:     trusted,
 				}
+
+				cfg.DBURL = dbURL
+				cfg.Port = 0
+				// One line: each line is a database write per new session.
+				cfg.MOTD = "neoirc test server"
+				cfg.HashcashBits = hashcashBits
+				cfg.OperName = operName
+				cfg.OperPassword = operPassword
+
+				return cfg, nil
 			},
 			newTestDB,
 			broker.New,
@@ -261,7 +255,7 @@ func newTestDB(
 	cfg *config.Config,
 ) (*db.Database, error) {
 	database, err := db.New(lifecycle, db.Params{ //nolint:exhaustruct
-		Logger: log, Config: cfg, PasswordCost: bcrypt.MinCost,
+		Logger: log, Config: cfg,
 	})
 	if err != nil {
 		return nil, fmt.Errorf("test db: %w", err)
@@ -836,7 +830,10 @@ func (tserver *testServer) postBody(
 func TestRequestBodyLimit(t *testing.T) {
 	t.Parallel()
 
-	const nick = "alice_bodylimit"
+	const (
+		maxMessageSize = 4096 // the default MAX_MESSAGE_SIZE
+		nick           = "alice_bodylimit"
+	)
 
 	endpoints := []struct {
 		name, path, value string
@@ -1753,67 +1750,52 @@ func TestConcurrentQuitsSendOneQuit(t *testing.T) {
 // that the second session then holds one QUIT from the
 // first, and that the first session is deleted: its tokens
 // are refused and its nick is free. It does all this
-// quitRaceTrials times, at once, each on a new server, because
+// quitRaceTrials times, each on a new server, because each
-// each trial logs in and logins are rate limited.
+// trial logs in and logins are rate limited.
 func checkQuitRace(
 	t *testing.T,
 	leave func(tserver *testServer, tokens []string),
 ) {
 	t.Helper()
 
-	for trial := range quitRaceTrials {
-		t.Run(fmt.Sprintf("trial %d", trial), func(t *testing.T) {
-			t.Parallel()
-
-			checkQuitRaceOnce(t, newTestServer(t), leave)
-		})
-	}
-}
-
-// checkQuitRaceOnce runs one trial of checkQuitRace on
-// tserver.
-func checkQuitRaceOnce(
-	t *testing.T,
-	tserver *testServer,
-	leave func(tserver *testServer, tokens []string),
-) {
-	t.Helper()
-
 	const nick = "racingquitter"
 
-	firstToken := tserver.createSession(nick)
+	for trial := range quitRaceTrials {
-	observerToken := tserver.createSession("raceobserver")
+		tserver := newTestServer(t)
+		firstToken := tserver.createSession(nick)
+		observerToken := tserver.createSession("raceobserver")
 
-	tserver.setPassword(nick)
+		tserver.setPassword(nick)
 
-	tokens := []string{firstToken, tserver.login(nick)}
+		tokens := []string{firstToken, tserver.login(nick)}
 
-	for _, token := range []string{firstToken, observerToken} {
+		for _, token := range []string{firstToken, observerToken} {
-		tserver.sendCommand(token, map[string]any{
+			tserver.sendCommand(token, map[string]any{
-			commandKey: joinCmd, toKey: "#quitrace",
+				commandKey: joinCmd, toKey: "#quitrace",
-		})
+			})
-	}
-
-	_, lastID := tserver.pollMessages(observerToken, 0)
-
-	leave(tserver, tokens)
-
-	msgs, _ := tserver.pollMessages(observerToken, lastID)
-
-	quits := countQuits(msgs, nick)
-	if quits != 1 {
-		t.Errorf("%d QUITs, want 1: %v", quits, msgs)
-	}
-
-	for _, token := range tokens {
-		status, _ := tserver.getState(token)
-		if status != http.StatusUnauthorized {
-			t.Errorf("state got %d, want 401", status)
 		}
-	}
 
-	// createSession fails the test if the nick is taken.
+		_, lastID := tserver.pollMessages(observerToken, 0)
-	tserver.createSession(nick)
+
+		leave(tserver, tokens)
+
+		msgs, _ := tserver.pollMessages(observerToken, lastID)
+
+		quits := countQuits(msgs, nick)
+		if quits != 1 {
+			t.Errorf("trial %d: %d QUITs, want 1: %v", trial, quits, msgs)
+		}
+
+		for _, token := range tokens {
+			status, _ := tserver.getState(token)
+			if status != http.StatusUnauthorized {
+				t.Errorf("trial %d: state got %d, want 401", trial, status)
+			}
+		}
+
+		// createSession fails the test if the nick is taken.
+		tserver.createSession(nick)
+	}
 }
 
 // TestLogoutOfOneClientKeepsSession checks that when one of
@@ -1951,28 +1933,11 @@ const (
 	// return once the session has left.
 	quitWakeDeadline = 5 * time.Second
 
-	// pollWaitStep is how often waitForLongPoll checks
+	// pollWaitStep is how often checkQuitWakesPoll checks
 	// whether the long poll is waiting yet.
 	pollWaitStep = 10 * time.Millisecond
 )
 
-// waitForLongPoll waits until a long poll of the session
-// sessionID is waiting, and fails the test if none is within
-// quitWakeDeadline.
-func (tserver *testServer) waitForLongPoll(sessionID int64) {
-	tserver.t.Helper()
-
-	deadline := time.Now().Add(quitWakeDeadline)
-
-	for tserver.broker.ListenerCount(sessionID) == 0 {
-		if time.Now().After(deadline) {
-			tserver.t.Fatal("the long poll did not start waiting")
-		}
-
-		time.Sleep(pollWaitStep)
-	}
-}
-
 // TestQuitWakesPeerLongPoll checks that a session's QUIT
 // wakes the long poll of a user who shares a channel with
 // it.
@@ -2047,7 +2012,15 @@ func checkQuitWakesPoll(
 		msgs, pollErr = tserver.longPoll(peerToken, lastID, quitWakePollTimeout)
 	}()
 
-	tserver.waitForLongPoll(peerID)
+	deadline := time.Now().Add(quitWakeDeadline)
+
+	for tserver.broker.ListenerCount(peerID) == 0 {
+		if time.Now().After(deadline) {
+			t.Fatal("the long poll did not start waiting")
+		}
+
+		time.Sleep(pollWaitStep)
+	}
 
 	leave(tserver, token)
 
@@ -2877,12 +2850,7 @@ func TestLongPoll(t *testing.T) {
 		pollMsgs = result.Messages
 	}()
 
-	bobID, err := tserver.database.GetSessionByNick(t.Context(), "lp_bob")
+	time.Sleep(200 * time.Millisecond)
-	if err != nil {
-		t.Fatalf("get session of lp_bob: %v", err)
-	}
-
-	tserver.waitForLongPoll(bobID)
 
 	tserver.sendCommand(aliceToken, map[string]any{
 		commandKey: privmsgCmd,
@@ -3041,18 +3009,18 @@ func TestGetMessagesRemovesWaitChannel(t *testing.T) {
 		longTimeout = 10
 
 		// shortTimeout, in seconds, is the timeout of the
-		// request that waits it out.
+		// requests that wait it out.
 		shortTimeout = 1
 	)
 
 	// queued is whether a message is queued before the request,
-	// whose timeout is in seconds. failingRead and notified are
+	// whose timeout is in seconds. failingRead is as for
-	// as for getMessagesFailingRead. wantReads is how many times
+	// getMessagesFailingRead. wantReads is how many times the
-	// the handler reads the queue: once if it answers at once,
+	// handler reads the queue: once if it answers at once,
 	// twice if it waits first.
 	tests := []struct {
 		name                  string
-		queued, notified      bool
+		queued                bool
 		timeout, failingRead  int
 		wantReads, wantStatus int
 	}{
@@ -3073,9 +3041,9 @@ func TestGetMessagesRemovesWaitChannel(t *testing.T) {
 			wantReads: 1, wantStatus: http.StatusInternalServerError,
 		},
 		{
-			name: "read after the wait failed", notified: true,
+			name: "read after the wait failed", timeout: shortTimeout,
-			timeout: handlers.MaxLongPollTimeout, failingRead: 2,
+			failingRead: 2, wantReads: 2,
-			wantReads: 2, wantStatus: http.StatusInternalServerError,
+			wantStatus: http.StatusInternalServerError,
 		},
 	}
 
@@ -3107,7 +3075,7 @@ func TestGetMessagesRemovesWaitChannel(t *testing.T) {
 			}
 
 			status, reads := tserver.getMessagesFailingRead(
-				token, sessionID, lastID, tc.timeout, tc.failingRead, tc.notified,
+				token, lastID, tc.timeout, tc.failingRead,
 			)
 			if status != tc.wantStatus {
 				t.Errorf("status %d, want %d", status, tc.wantStatus)
@@ -3124,17 +3092,14 @@ func TestGetMessagesRemovesWaitChannel(t *testing.T) {
 }
 
 // getMessagesFailingRead sends GET /api/v1/messages for the
-// client token of the session sessionID, with timeout and
+// client token with timeout and after afterID. The handler's
-// after afterID. The handler's read of the queue numbered
+// read of the queue numbered failingRead, counting from 1,
-// failingRead, counting from 1, fails; with 0, none does.
+// fails; with 0, none does. It returns the response status
-// With notified, it notifies the broker once the request
+// and how many times the handler read the queue.
-// waits. It returns the response status and how many times
-// the handler read the queue.
 func (tserver *testServer) getMessagesFailingRead(
 	token string,
-	sessionID, afterID int64,
+	afterID int64,
 	timeout, failingRead int,
-	notified bool,
 ) (int, int) {
 	tserver.t.Helper()
 
@@ -3156,45 +3121,20 @@ func (tserver *testServer) getMessagesFailingRead(
 		)
 	})
 
-	var (
+	resp, err := doRequestAuth(
-		status int
+		tserver.t, http.MethodGet,
-		err    error
+		tserver.url(fmt.Sprintf(
+			"%s?timeout=%d&after=%d", apiMessages, timeout, afterID,
+		)),
+		token, nil,
 	)
-
-	answered := make(chan struct{})
-
-	go func() {
-		defer close(answered)
-
-		var resp *http.Response
-
-		resp, err = doRequestAuth(
-			tserver.t, http.MethodGet,
-			tserver.url(fmt.Sprintf(
-				"%s?timeout=%d&after=%d", apiMessages, timeout, afterID,
-			)),
-			token, nil,
-		)
-		if err != nil {
-			return
-		}
-
-		status = resp.StatusCode
-		_ = resp.Body.Close()
-	}()
-
-	if notified {
-		tserver.waitForLongPoll(sessionID)
-		tserver.broker.Notify(sessionID)
-	}
-
-	<-answered
-
 	if err != nil {
 		tserver.t.Fatalf("get messages: %v", err)
 	}
 
-	return status, reads
+	_ = resp.Body.Close()
+
+	return resp.StatusCode, reads
 }
 
 // TestLongPollRemovesWaitChannelWhenClientGivesUp checks that
@@ -4403,11 +4343,12 @@ func TestLoginRateLimitIgnoresForwardedHeaders(t *testing.T) {
 }
 
 func TestLoginRateLimitPerClientBehindTrustedProxy(t *testing.T) {
-	t.Parallel()
-
 	// The test client connects from 127.0.0.1. Trusted as a proxy, it
-	// passes each client's address in X-Forwarded-For.
+	// passes each client's address in X-Forwarded-For. t.Setenv rules
-	tserver := newTestServerWith(t, 0, "", "", "127.0.0.1")
+	// out t.Parallel.
+	t.Setenv("TRUSTED_PROXIES", "127.0.0.1")
+
+	tserver := newTestServer(t)
 
 	// An empty JSON object is refused after the rate limit counts the
 	// attempt, so no attempt checks a password or looks up a hostname.
@@ -5138,9 +5079,7 @@ func TestRefusedSessionLeavesStampUnspent(t *testing.T) {
 		badNick = "bad nick"
 	)
 
-	tserver := newTestServerWith(
+	tserver := newTestServerWith(t, bits, "", "")
-		t, bits, "", "", config.DefaultTrustedProxies,
-	)
 
 	// A server with no SERVER_NAME takes stamps for "neoirc".
 	status := postSessionWithStamp(
@@ -5346,7 +5285,6 @@ func newTestServerWithOper(
 
 	return newTestServerWith(
 		t, 0, testOperName, testOperPassword,
-		config.DefaultTrustedProxies,
 	)
 }
 

internal/handlers/export_test.go

@@ -6,10 +6,6 @@ import (
 	"sneak.berlin/go/neoirc/internal/db"
 )
 
-// MaxLongPollTimeout is the longest HandleGetMessages waits, in
-// seconds.
-const MaxLongPollTimeout = maxLongPollTimeout
-
 // SetPollMessages makes HandleGetMessages read the client
 // output queue with poll in place of Database.PollMessages.
 func (hdlr *Handlers) SetPollMessages(

internal/ircserver/conn.go

@@ -70,10 +70,6 @@ type Conn struct {
 	closed      bool
 	killed      bool
 
-	// pollInterval is how often the relay checks the client
-	// output queue when no broker notification arrives.
-	pollInterval time.Duration
-
 	// quitReason is the reason in the QUIT that peers are
 	// sent when the connection ends. The client's QUIT
 	// replaces it.
@@ -87,7 +83,6 @@ func newConn(
 	brk *broker.Broker,
 	cfg *config.Config,
 	svc *service.Service,
-	poll time.Duration,
 ) *Conn {
 	host, _, _ := net.SplitHostPort(tcpConn.RemoteAddr().String())
 
@@ -106,8 +101,6 @@ func newConn(
 		serverSfx:  srvName,
 		remoteIP:   host,
 		quitReason: "Connection closed",
-
-		pollInterval: poll,
 	}
 
 	conn.commands = conn.buildCommandMap()

internal/ircserver/export_test.go

@@ -14,16 +14,16 @@ import (
 )
 
 // NewTestServer creates a Server suitable for testing, whose
-// connections use interval, deadline and poll in place of
+// connections use interval and deadline in place of
-// pingInterval, pongDeadline and pollInterval, and resolve in
+// pingInterval and pongDeadline, and resolve in place of
-// place of resolveHost.
+// resolveHost.
 // The caller must call Stop() when finished.
 func NewTestServer(
 	log *slog.Logger,
 	cfg *config.Config,
 	database *db.Database,
 	brk *broker.Broker,
-	interval, deadline, poll time.Duration,
+	interval, deadline time.Duration,
 	resolve func(ctx context.Context, addr string) string,
 ) *Server {
 	globs := &globals.Globals{
@@ -46,18 +46,10 @@ func NewTestServer(
 
 		pingInterval: interval,
 		pongDeadline: deadline,
-		pollInterval: poll,
-		stopTimeout:  stopTimeout,
 		resolveHost:  resolve,
 	}
 }
 
-// SetStopTimeout makes Stop wait at most timeout for the
-// connections' cleanup.
-func (s *Server) SetStopTimeout(timeout time.Duration) {
-	s.stopTimeout = timeout
-}
-
 // ResolveHost is the reverse DNS lookup that a server made by
 // New does for each client.
 func ResolveHost(ctx context.Context, addr string) string {
@@ -107,6 +99,10 @@ const PingInterval = pingInterval
 // for a line before it closes the connection.
 const PongDeadline = pongDeadline
 
+// StopTimeout is the longest Stop waits for the connections'
+// cleanup.
+const StopTimeout = stopTimeout
+
 // NewTestConn returns a Conn for nick on tcpConn, without a
 // server, database or service behind it.
 func NewTestConn(
@@ -115,7 +111,7 @@ func NewTestConn(
 	tcpConn net.Conn,
 	nick string,
 ) *Conn {
-	conn := newConn(tcpConn, log, nil, nil, cfg, nil, pollInterval)
+	conn := newConn(tcpConn, log, nil, nil, cfg, nil)
 	conn.nick = nick
 
 	return conn

internal/ircserver/integration_test.go

@@ -3,6 +3,7 @@ package ircserver_test
 import (
 	"strings"
 	"testing"
+	"time"
 
 	"sneak.berlin/go/neoirc/internal/config"
 )
@@ -1507,6 +1508,9 @@ func TestIntegrationThirdClientObserver(t *testing.T) {
 	bob.joinAndDrain("#trio")
 	carol.joinAndDrain("#trio")
 
+	// Drain join notifications.
+	time.Sleep(100 * time.Millisecond)
+
 	// alice sends; both bob and carol should receive.
 	alice.send("PRIVMSG #trio :hello trio")
 

internal/ircserver/relay.go

@@ -17,7 +17,7 @@ import (
 func (c *Conn) relayMessages(ctx context.Context) {
 	// Use a ticker as a fallback; primary wakeup is via
 	// broker notification.
-	ticker := time.NewTicker(c.pollInterval)
+	ticker := time.NewTicker(pollInterval)
 	defer ticker.Stop()
 
 	for {

internal/ircserver/relay_test.go

@@ -9,7 +9,6 @@ import (
 	"time"
 
 	"golang.org/x/crypto/bcrypt"
-	"sneak.berlin/go/neoirc/internal/config"
 	"sneak.berlin/go/neoirc/internal/dbtest"
 	"sneak.berlin/go/neoirc/internal/ircserver"
 	"sneak.berlin/go/neoirc/internal/service"
@@ -59,11 +58,7 @@ func (env *testEnv) queueMessage(
 func TestRelayKeepsOneWaitChannel(t *testing.T) {
 	t.Parallel()
 
-	env := newTestEnvWithResolver(
+	env := newTestEnv(t)
-		t, &config.Config{ServerName: testServerName},
-		ircserver.PingInterval, ircserver.PongDeadline,
-		ircserver.PollInterval, ircserver.ResolveHost,
-	)
 
 	client := env.dial(t)
 	client.register("idle")
@@ -124,63 +119,6 @@ func (env *testEnv) checkOneWaitChannel(
 	}
 }
 
-// TestRelayDeliversAfterFailedRead checks that when the relay
-// cannot read the client output queue, it waits for the next
-// notification, and delivers once the queue can be read again.
-func TestRelayDeliversAfterFailedRead(t *testing.T) {
-	t.Parallel()
-
-	env := newTestEnv(t)
-	client := env.dial(t)
-	client.register("reader")
-
-	sessionID, err := env.database.GetSessionByNick(t.Context(), "reader")
-	if err != nil {
-		t.Fatalf("get session of reader: %v", err)
-	}
-
-	dbtest.Exec(t, env.dbURL,
-		"ALTER TABLE client_queues RENAME TO hidden_queues")
-
-	// Each pass of the relay takes a wait channel and then reads
-	// the queue. Once it holds a channel after the second
-	// notification, the read after the first one has failed.
-	for range 2 {
-		env.waitForWaitChannel(t, sessionID)
-		env.brk.Notify(sessionID)
-	}
-
-	env.waitForWaitChannel(t, sessionID)
-
-	dbtest.Exec(t, env.dbURL,
-		"ALTER TABLE hidden_queues RENAME TO client_queues")
-
-	env.queueMessage(
-		t, "reader", "PRIVMSG", "carol", "reader", []string{"readable"},
-	)
-
-	client.readUntil(func(l string) bool {
-		return strings.Contains(l, "readable")
-	})
-}
-
-// waitForWaitChannel waits until the session sessionID holds a
-// broker wait channel, and fails the test if it does not
-// within testTimeout.
-func (env *testEnv) waitForWaitChannel(t *testing.T, sessionID int64) {
-	t.Helper()
-
-	deadline := time.Now().Add(testTimeout)
-
-	for env.brk.ListenerCount(sessionID) == 0 {
-		if time.Now().After(deadline) {
-			t.Fatal("the relay is not waiting for a notification")
-		}
-
-		time.Sleep(relayCheckStep)
-	}
-}
-
 // TestRelayMultiLineBody checks that each line of a PRIVMSG
 // or NOTICE body sent over the HTTP API reaches an IRC
 // listener user as its own line.

internal/ircserver/server.go

@@ -53,11 +53,6 @@ type Server struct {
 	pingInterval time.Duration
 	pongDeadline time.Duration
 
-	// pollInterval and stopTimeout are the constants of the
-	// same names, except in tests, which change them.
-	pollInterval time.Duration
-	stopTimeout  time.Duration
-
 	// resolveHost is the function of the same name, except in
 	// tests, which replace it with one that blocks.
 	resolveHost func(ctx context.Context, addr string) string
@@ -84,8 +79,6 @@ func New(
 
 		pingInterval: pingInterval,
 		pongDeadline: pongDeadline,
-		pollInterval: pollInterval,
-		stopTimeout:  stopTimeout,
 		resolveHost:  resolveHost,
 	}
 
@@ -161,10 +154,10 @@ func (s *Server) stop() {
 
 	select {
 	case <-done:
-	case <-time.After(s.stopTimeout):
+	case <-time.After(stopTimeout):
 		s.log.Error(
 			"irc connections not cleaned up before stop timeout",
-			"timeout", s.stopTimeout,
+			"timeout", stopTimeout,
 		)
 	}
 }
@@ -188,7 +181,7 @@ func (s *Server) acceptLoop(ctx context.Context) {
 
 		client := newConn(
 			tcpConn, s.log,
-			s.database, s.brk, s.cfg, s.svc, s.pollInterval,
+			s.database, s.brk, s.cfg, s.svc,
 		)
 
 		s.mu.Lock()

internal/ircserver/server_test.go

@@ -18,7 +18,6 @@ import (
 	"time"
 
 	"go.uber.org/fx/fxtest"
-	"golang.org/x/crypto/bcrypt"
 	"sneak.berlin/go/neoirc/internal/broker"
 	"sneak.berlin/go/neoirc/internal/config"
 	"sneak.berlin/go/neoirc/internal/db"
@@ -36,12 +35,6 @@ import (
 // enough for a heavily loaded host.
 const testTimeout = 30 * time.Second
 
-// testPollInterval is how often the relay of a test server
-// checks the client output queue without a broker
-// notification. It is so long that the relay delivers only on
-// notification, and a test fails when one is missing.
-const testPollInterval = time.Hour
-
 // testEnv holds the shared test infrastructure.
 type testEnv struct {
 	dbURL    string
@@ -101,19 +94,16 @@ func newTestEnvWithPingTimes(
 	t.Helper()
 
 	return newTestEnvWithResolver(
-		t, cfg, interval, deadline, testPollInterval,
+		t, cfg, interval, deadline, ircserver.ResolveHost,
-		ircserver.ResolveHost,
 	)
 }
 
 // newTestEnvWithResolver is newTestEnvWithPingTimes, except
-// that the relay checks the client output queue every poll
+// that the server looks up a client's hostname with resolve.
-// without a broker notification, and the server looks up a
-// client's hostname with resolve.
 func newTestEnvWithResolver(
 	t *testing.T,
 	cfg *config.Config,
-	interval, deadline, poll time.Duration,
+	interval, deadline time.Duration,
 	resolve func(ctx context.Context, addr string) string,
 ) *testEnv {
 	t.Helper()
@@ -129,9 +119,8 @@ func newTestEnvWithResolver(
 	}
 
 	database, err := db.New(lifecycle, db.Params{
-		Logger:       dbLog,
+		Logger: dbLog,
-		Config:       &config.Config{DBURL: dbURL},
+		Config: &config.Config{DBURL: dbURL},
-		PasswordCost: bcrypt.MinCost,
 	})
 	if err != nil {
 		t.Fatalf("new database: %v", err)
@@ -148,7 +137,7 @@ func newTestEnvWithResolver(
 	))
 
 	srv := ircserver.NewTestServer(
-		log, cfg, database, brk, interval, deadline, poll, resolve,
+		log, cfg, database, brk, interval, deadline, resolve,
 	)
 
 	// Port 0 makes the system pick a free port. dial reads it
@@ -444,8 +433,7 @@ func TestRegistrationWhileAnotherLookupIsPending(t *testing.T) {
 
 	env := newTestEnvWithResolver(
 		t, &config.Config{ServerName: testServerName},
-		ircserver.PingInterval, ircserver.PongDeadline,
+		ircserver.PingInterval, ircserver.PongDeadline, resolve,
-		testPollInterval, resolve,
 	)
 
 	env.dial(t)
@@ -1076,16 +1064,12 @@ func TestStopEndsSessions(t *testing.T) {
 }
 
 // TestStopReturnsWhileCleanupIsStuck checks that Stop stops
-// waiting for a connection's cleanup after its stop timeout,
+// waiting for a connection's cleanup after StopTimeout, so a
-// so a cleanup that cannot finish does not hold up stopping.
+// cleanup that cannot finish does not hold up stopping.
 func TestStopReturnsWhileCleanupIsStuck(t *testing.T) {
 	t.Parallel()
 
-	const stopTimeout = 100 * time.Millisecond
-
 	env := newTestEnv(t)
-	env.srv.SetStopTimeout(stopTimeout)
-
 	client := env.dial(t)
 
 	client.register("stuck")
@@ -1111,7 +1095,7 @@ func TestStopReturnsWhileCleanupIsStuck(t *testing.T) {
 
 	select {
 	case <-stopped:
-	case <-time.After(stopTimeout + testTimeout):
+	case <-time.After(ircserver.StopTimeout + testTimeout):
 		t.Error("Stop did not return while a cleanup was stuck")
 	}
 
@@ -1163,6 +1147,9 @@ func TestDirectMessage(t *testing.T) {
 	receiver := env.dial(t)
 	receiver.register("dmreceiver")
 
+	// Give relay goroutines time to start.
+	time.Sleep(100 * time.Millisecond)
+
 	sender.send("PRIVMSG dmreceiver :hello privately")
 
 	lines := receiver.readUntil(func(line string) bool {

internal/middleware/middleware.go

@@ -200,19 +200,24 @@ func (mware *Middleware) Logging() func(http.Handler) http.Handler {
 	}
 }
 
-// CORS returns middleware that lets a page on any origin read the
+// CORS returns middleware that handles Cross-Origin Resource Sharing.
-// response. Use it only on public, read-only routes.
+// AllowCredentials is true so browsers include cookies in
+// cross-origin API requests.
 func (mware *Middleware) CORS() func(http.Handler) http.Handler {
 	return cors.Handler(cors.Options{ //nolint:exhaustruct // optional fields
-		AllowedOrigins: []string{"*"},
+		AllowOriginFunc: func(
+			_ *http.Request, _ string,
+		) bool {
+			return true
+		},
 		AllowedMethods: []string{
 			"GET", "POST", "PUT", "DELETE", "OPTIONS",
 		},
 		AllowedHeaders: []string{
-			"Accept", "Authorization", "Content-Type", "X-CSRF-Token",
+			"Accept", "Content-Type", "X-CSRF-Token",
 		},
 		ExposedHeaders:   []string{"Link"},
-		AllowCredentials: false,
+		AllowCredentials: true,
 		MaxAge:           corsMaxAge,
 	})
 }

internal/server/routes.go

@@ -30,6 +30,7 @@ func (srv *Server) SetupRoutes() {
 		srv.router.Use(srv.mw.Metrics())
 	}
 
+	srv.router.Use(srv.mw.CORS())
 	srv.router.Use(srv.mw.CSP())
 	srv.router.Use(middleware.Timeout(routeTimeout))
 
@@ -44,7 +45,7 @@ func (srv *Server) SetupRoutes() {
 	}
 
 	// Health check.
-	srv.router.With(srv.mw.CORS()).Get(
+	srv.router.Get(
 		"/.well-known/healthcheck.json",
 		srv.handlers.HandleHealthCheck(),
 	)
@@ -68,7 +69,7 @@ func (srv *Server) SetupRoutes() {
 }
 
 func (srv *Server) setupAPIv1(router chi.Router) {
-	router.With(srv.mw.CORS()).Get(
+	router.Get(
 		"/server",
 		srv.handlers.HandleServerInfo(),
 	)

internal/server/server_test.go

@@ -6,10 +6,8 @@ package server_test
 
 import (
 	"fmt"
-	"maps"
 	"net"
 	"net/http"
-	"net/http/httptest"
 	"strconv"
 	"strings"
 	"testing"
@@ -190,88 +188,6 @@ func TestServeAfterStopDoesNotStopApp(t *testing.T) {
 	}
 }
 
-// TestCORSHeaders checks the Access-Control-Allow-* headers on the
-// answers to requests from another origin. The public, read-only
-// routes answer with Access-Control-Allow-Origin: * alone. Routes
-// that need the cookie, and a preflight to one, answer with none.
-func TestCORSHeaders(t *testing.T) {
-	var srv *server.Server
-
-	startApp(t, fx.Populate(&srv))
-
-	tests := []struct {
-		name          string
-		method        string
-		path          string
-		requestMethod string
-		wantHeaders   map[string]string
-	}{
-		{
-			name:        "server information",
-			method:      http.MethodGet,
-			path:        "/api/v1/server",
-			wantHeaders: map[string]string{"Access-Control-Allow-Origin": "*"},
-		},
-		{
-			name:        "health check",
-			method:      http.MethodGet,
-			path:        "/.well-known/healthcheck.json",
-			wantHeaders: map[string]string{"Access-Control-Allow-Origin": "*"},
-		},
-		{
-			name:   "send",
-			method: http.MethodPost,
-			path:   "/api/v1/messages",
-		},
-		{
-			name:   "state",
-			method: http.MethodGet,
-			path:   "/api/v1/state",
-		},
-		{
-			name:          "preflight for send",
-			method:        http.MethodOptions,
-			path:          "/api/v1/messages",
-			requestMethod: http.MethodPost,
-		},
-	}
-
-	for _, test := range tests {
-		t.Run(test.name, func(t *testing.T) {
-			request := httptest.NewRequestWithContext(
-				t.Context(), test.method,
-				"http://chat.example.com"+test.path, nil,
-			)
-			request.Header.Set("Origin", "http://blog.example.com")
-
-			if test.requestMethod != "" {
-				request.Header.Set(
-					"Access-Control-Request-Method", test.requestMethod,
-				)
-			}
-
-			recorder := httptest.NewRecorder()
-
-			srv.ServeHTTP(recorder, request)
-
-			gotHeaders := map[string]string{}
-
-			for name := range recorder.Header() {
-				if strings.HasPrefix(name, "Access-Control-Allow-") {
-					gotHeaders[name] = recorder.Header().Get(name)
-				}
-			}
-
-			if !maps.Equal(gotHeaders, test.wantHeaders) {
-				t.Errorf(
-					"Access-Control-Allow-* headers are %v, want %v",
-					gotHeaders, test.wantHeaders,
-				)
-			}
-		})
-	}
-}
-
 // startApp starts the app newApp builds, with the HTTP port
 // set to 0, so the system gives the server a free port.
 func startApp(

internal/service/service_test.go

@@ -1,3 +1,7 @@
+// Tests use a global viper instance for configuration,
+// making parallel execution unsafe.
+//
+//nolint:paralleltest
 package service_test
 
 import (
@@ -55,12 +59,28 @@ func newTestEnv(t *testing.T) *testEnv {
 				}
 			},
 			logger.New,
-			func() *config.Config {
+			func(
-				return &config.Config{
+				lifecycle fx.Lifecycle,
-					DBURL:        dbURL,
+				globs *globals.Globals,
-					OperName:     "admin",
+				log *logger.Logger,
-					OperPassword: "secret",
+			) (*config.Config, error) {
+				cfg, err := config.New(
+					lifecycle, config.Params{ //nolint:exhaustruct
+						Globals: globs, Logger: log,
+					},
+				)
+				if err != nil {
+					return nil, fmt.Errorf(
+						"test config: %w", err,
+					)
 				}
+
+				cfg.DBURL = dbURL
+				cfg.Port = 0
+				cfg.OperName = "admin"
+				cfg.OperPassword = "secret"
+
+				return cfg, nil
 			},
 			func(
 				lifecycle fx.Lifecycle,
@@ -116,8 +136,6 @@ func createSession(
 // environment starts on an empty database while another one
 // is still open.
 func TestEachTestEnvHasItsOwnDatabase(t *testing.T) {
-	t.Parallel()
-
 	ctx := t.Context()
 
 	first := newTestEnv(t)
@@ -128,8 +146,6 @@ func TestEachTestEnvHasItsOwnDatabase(t *testing.T) {
 }
 
 func TestFanOut(t *testing.T) {
-	t.Parallel()
-
 	env := newTestEnv(t)
 	ctx := t.Context()
 
@@ -157,8 +173,6 @@ func TestFanOut(t *testing.T) {
 }
 
 func TestJoinChannel(t *testing.T) {
-	t.Parallel()
-
 	env := newTestEnv(t)
 	ctx := t.Context()
 
@@ -199,8 +213,6 @@ func TestJoinChannel(t *testing.T) {
 }
 
 func TestPartChannel(t *testing.T) {
-	t.Parallel()
-
 	env := newTestEnv(t)
 	ctx := t.Context()
 
@@ -301,8 +313,6 @@ func joinConcurrently(
 // concurrent JOINs of a +l 2 channel with one member, one
 // gets in and the other gets ERR_CHANNELISFULL.
 func TestConcurrentJoinsRespectUserLimit(t *testing.T) {
-	t.Parallel()
-
 	const userLimit = 2
 
 	env := newTestEnv(t)
@@ -365,8 +375,6 @@ func TestConcurrentJoinsRespectUserLimit(t *testing.T) {
 // two concurrent JOINs that create a channel, exactly one
 // makes its session the operator.
 func TestConcurrentFirstJoinsMakeOneOperator(t *testing.T) {
-	t.Parallel()
-
 	env := newTestEnv(t)
 	ctx := t.Context()
 
@@ -418,8 +426,6 @@ func TestConcurrentFirstJoinsMakeOneOperator(t *testing.T) {
 // either joins a channel that still exists or gets
 // ERR_NOSUCHCHANNEL, and never fails otherwise.
 func TestJoinConcurrentWithLastPart(t *testing.T) {
-	t.Parallel()
-
 	env := newTestEnv(t)
 	ctx := t.Context()
 
@@ -485,8 +491,6 @@ func TestJoinConcurrentWithLastPart(t *testing.T) {
 // quits, gets in only once the channel is deleted, into a
 // new channel of that name with no key.
 func TestJoinConcurrentWithLastQuit(t *testing.T) {
-	t.Parallel()
-
 	env := newTestEnv(t)
 	ctx := t.Context()
 
@@ -565,95 +569,81 @@ const quitCrowdSize = 10
 // ahead of that JOIN. The quitting session is also on a
 // channel with quitCrowdSize other sessions, made before the
 // watcher's channel, so that its QUIT reaches the watcher
-// last. Each trial runs on a database of its own.
+// last.
 func TestQuitQueuedAheadOfNewNickHoldersJoin(t *testing.T) {
-	t.Parallel()
+	env := newTestEnv(t)
+	ctx := t.Context()
 
 	for trial := range concurrentJoinTrials {
-		t.Run(fmt.Sprintf("trial %d", trial), func(t *testing.T) {
+		nick := fmt.Sprintf("reused%d", trial)
-			t.Parallel()
+		crowd := fmt.Sprintf("#crowd%d", trial)
+		shared := fmt.Sprintf("#shared%d", trial)
+		quitterSID := createSession(ctx, t, env.db, nick)
 
-			checkQuitQueuedAheadOfJoin(t, newTestEnv(t))
+		for _, channel := range []string{crowd, shared} {
-		})
+			_, err := env.svc.JoinChannel(ctx, quitterSID, 0, nick, channel, "")
-	}
+			if err != nil {
-}
+				t.Fatalf("join %s: %v", channel, err)
-
+			}
-// checkQuitQueuedAheadOfJoin runs one trial of
-// TestQuitQueuedAheadOfNewNickHoldersJoin on env.
-func checkQuitQueuedAheadOfJoin(t *testing.T, env *testEnv) {
-	t.Helper()
-
-	const (
-		nick        = "reused"
-		crowd       = "#crowd"
-		shared      = "#shared"
-		watcherNick = "watcher"
-	)
-
-	ctx := t.Context()
-	quitterSID := createSession(ctx, t, env.db, nick)
-
-	for _, channel := range []string{crowd, shared} {
-		_, err := env.svc.JoinChannel(ctx, quitterSID, 0, nick, channel, "")
-		if err != nil {
-			t.Fatalf("join %s: %v", channel, err)
 		}
-	}
 
-	for member := range quitCrowdSize {
+		for member := range quitCrowdSize {
-		memberNick := fmt.Sprintf("crowd%d", member)
+			memberNick := fmt.Sprintf("crowd%dx%d", trial, member)
-		memberSID := createSession(ctx, t, env.db, memberNick)
+			memberSID := createSession(ctx, t, env.db, memberNick)
 
-		_, err := env.svc.JoinChannel(ctx, memberSID, 0, memberNick, crowd, "")
+			_, err := env.svc.JoinChannel(ctx, memberSID, 0, memberNick, crowd, "")
-		if err != nil {
+			if err != nil {
-			t.Fatalf("join %s: %v", memberNick, err)
+				t.Fatalf("join %s: %v", memberNick, err)
+			}
 		}
-	}
 
-	watcherSID, watcherClientID, _, err := env.db.CreateSession(
+		watcherNick := fmt.Sprintf("watcher%d", trial)
-		ctx, watcherNick, watcherNick, "localhost", "127.0.0.1",
-	)
-	if err != nil {
-		t.Fatalf("create session %s: %v", watcherNick, err)
-	}
 
-	_, err = env.svc.JoinChannel(ctx, watcherSID, 0, watcherNick, shared, "")
+		watcherSID, watcherClientID, _, err := env.db.CreateSession(
-	if err != nil {
+			ctx, watcherNick, watcherNick, "localhost", "127.0.0.1",
-		t.Fatalf("join %s: %v", watcherNick, err)
-	}
-
-	_, lastQueueID, err := env.db.PollMessages(ctx, watcherClientID, 0, 0)
-	if err != nil {
-		t.Fatalf("poll: %v", err)
-	}
-
-	errs := runConcurrently(
-		func() error {
-			env.svc.BroadcastQuit(ctx, quitterSID, nick, "")
-
-			return nil
-		},
-		func() error {
-			return takeNickAndJoin(ctx, env, nick, shared)
-		},
-	)
-	if errs[1] != nil {
-		t.Fatalf("new session: %v", errs[1])
-	}
-
-	msgs, _, err := env.db.PollMessages(
-		ctx, watcherClientID, lastQueueID, 0,
-	)
-	if err != nil {
-		t.Fatalf("poll: %v", err)
-	}
-
-	commands := commandsFrom(msgs, nick)
-	if !slices.Equal(commands, []string{irc.CmdQuit, irc.CmdJoin}) {
-		t.Errorf(
-			"watcher got %v from %s, want QUIT then JOIN",
-			commands, nick,
 		)
+		if err != nil {
+			t.Fatalf("create session %s: %v", watcherNick, err)
+		}
+
+		_, err = env.svc.JoinChannel(ctx, watcherSID, 0, watcherNick, shared, "")
+		if err != nil {
+			t.Fatalf("join %s: %v", watcherNick, err)
+		}
+
+		_, lastQueueID, err := env.db.PollMessages(ctx, watcherClientID, 0, 0)
+		if err != nil {
+			t.Fatalf("poll: %v", err)
+		}
+
+		errs := runConcurrently(
+			func() error {
+				env.svc.BroadcastQuit(ctx, quitterSID, nick, "")
+
+				return nil
+			},
+			func() error {
+				return takeNickAndJoin(ctx, env, nick, shared)
+			},
+		)
+		if errs[1] != nil {
+			t.Fatalf("trial %d: new session: %v", trial, errs[1])
+		}
+
+		msgs, _, err := env.db.PollMessages(
+			ctx, watcherClientID, lastQueueID, 0,
+		)
+		if err != nil {
+			t.Fatalf("poll: %v", err)
+		}
+
+		commands := commandsFrom(msgs, nick)
+		if !slices.Equal(commands, []string{irc.CmdQuit, irc.CmdJoin}) {
+			t.Errorf(
+				"trial %d: watcher got %v from %s, want QUIT then JOIN",
+				trial, commands, nick,
+			)
+		}
 	}
 }
 
@@ -701,8 +691,6 @@ func commandsFrom(msgs []db.IRCMessage, nick string) []string {
 // into a +i channel uses the invite up, so that a JOIN
 // after leaving gets ERR_INVITEONLYCHAN.
 func TestJoinUsesUpInvite(t *testing.T) {
-	t.Parallel()
-
 	const channel = "#club"
 
 	env := newTestEnv(t)
@@ -748,8 +736,6 @@ func TestJoinUsesUpInvite(t *testing.T) {
 // session's nick, username and hostname refuses its JOIN
 // with ERR_BANNEDFROMCHAN.
 func TestJoinRefusedByHostmaskBan(t *testing.T) {
-	t.Parallel()
-
 	const channel = "#club"
 
 	env := newTestEnv(t)
@@ -788,8 +774,6 @@ func TestJoinRefusedByHostmaskBan(t *testing.T) {
 // keeps a channel other members are still on and deletes
 // the channel when its last member parts.
 func TestPartDeletesChannelOnlyWhenEmpty(t *testing.T) {
-	t.Parallel()
-
 	const channel = "#room"
 
 	env := newTestEnv(t)
@@ -837,8 +821,6 @@ func TestPartDeletesChannelOnlyWhenEmpty(t *testing.T) {
 // TestKickOfLastMemberDeletesChannel checks that a KICK
 // that leaves a channel with no members deletes it.
 func TestKickOfLastMemberDeletesChannel(t *testing.T) {
-	t.Parallel()
-
 	const channel = "#room"
 
 	env := newTestEnv(t)
@@ -863,8 +845,6 @@ func TestKickOfLastMemberDeletesChannel(t *testing.T) {
 }
 
 func TestSendChannelMessage(t *testing.T) {
-	t.Parallel()
-
 	env := newTestEnv(t)
 	ctx := t.Context()
 
@@ -912,8 +892,6 @@ func TestSendChannelMessage(t *testing.T) {
 }
 
 func TestBroadcastQuit(t *testing.T) {
-	t.Parallel()
-
 	env := newTestEnv(t)
 	ctx := t.Context()
 
@@ -951,8 +929,6 @@ func TestBroadcastQuit(t *testing.T) {
 // error as a DM to an unknown nick. The trigger deletes the
 // target's session just before the DM is stored.
 func TestSendDirectMessageTargetQuits(t *testing.T) {
-	t.Parallel()
-
 	env := newTestEnv(t)
 	ctx := t.Context()
 
@@ -984,8 +960,6 @@ func TestSendDirectMessageTargetQuits(t *testing.T) {
 // trigger deletes the channel just before the message is
 // stored.
 func TestSendChannelMessageChannelDeleted(t *testing.T) {
-	t.Parallel()
-
 	env := newTestEnv(t)
 	ctx := t.Context()
 
@@ -1017,8 +991,6 @@ func TestSendChannelMessageChannelDeleted(t *testing.T) {
 }
 
 func TestSendChannelMessage_Moderated(t *testing.T) {
-	t.Parallel()
-
 	env := newTestEnv(t)
 	ctx := t.Context()
 
@@ -1070,8 +1042,6 @@ func TestSendChannelMessage_Moderated(t *testing.T) {
 // not spend its hashcash stamp: the operator can then send
 // the same message with it.
 func TestRefusedChannelMessageLeavesStampUnspent(t *testing.T) {
-	t.Parallel()
-
 	const (
 		channel = "#paid"
 		bits    = 2
@@ -1097,8 +1067,6 @@ func TestRefusedChannelMessageLeavesStampUnspent(t *testing.T) {
 
 	for _, refusal := range refusals {
 		t.Run(refusal.name, func(t *testing.T) {
-			t.Parallel()
-
 			env := newTestEnv(t)
 			ctx := t.Context()
 
@@ -1151,8 +1119,6 @@ func TestRefusedChannelMessageLeavesStampUnspent(t *testing.T) {
 }
 
 func TestQueryUserMode(t *testing.T) {
-	t.Parallel()
-
 	env := newTestEnv(t)
 	ctx := t.Context()
 
@@ -1203,8 +1169,6 @@ func TestQueryUserMode(t *testing.T) {
 }
 
 func TestUserhostReply(t *testing.T) {
-	t.Parallel()
-
 	env := newTestEnv(t)
 	ctx := t.Context()
 
@@ -1310,14 +1274,10 @@ func applyUserModeTests() []applyUserModeTest {
 }
 
 func TestApplyUserMode(t *testing.T) {
-	t.Parallel()
-
 	env := newTestEnv(t)
 
 	for i, test := range applyUserModeTests() {
 		t.Run(test.modeStr, func(t *testing.T) {
-			t.Parallel()
-
 			ctx := t.Context()
 			sid := createSession(
 				ctx, t, env.db, fmt.Sprintf("user%d", i),