Keep foreign keys on for every database connection (closes #207)

SQLite keeps the foreign keys setting per connection, and the server
turned it on once with a PRAGMA. A query cancelled while it runs makes
the pool close its only connection and open a new one, which then ran
without foreign keys until a restart.

connect now adds `_pragma=foreign_keys(1)` to the database URL. The
driver runs every `_pragma` parameter on each connection it opens, so
this also holds for a `DBURL` without `_pragma` parameters. The new
test cancels a query on a file database, then checks that the tables
are still there and that foreign keys are on.

Model: opus-5-5

.golangci.yml

@@ -61,10 +61,6 @@ linters:
               desc: >-
                 Test-support code belongs in test files and in packages whose
                 directory name ends in test, not in the shipped binary.
-            - pkg: sneak.berlin/go/neoirc/internal/dbtest
-              desc: >-
-                Test-support code belongs in test files and in packages whose
-                directory name ends in test, not in the shipped binary.
     # Only decisions already recorded in the Go package defaults are
     # listed here. Every entry matches the module path exactly.
     gomodguard_v2:

AGENTS.md

@@ -1,73 +1,55 @@
-# Rules for coding agents
+# AGENTS.md — Rules for AI Agents
 
-This file holds the rules for coding agents working in this repository.
-`CONVENTIONS.md` defines the architecture. `REPO_POLICIES.md` defines the
-repository standards. Both are copies of shared documents. Do not edit them
-here.
+## Before Every Commit
 
-## Before every commit
+1. **Format**: `make fmt`
+2. **Check**: `make check` — the tests and the linter, which run in Docker, and
+   the format check: all passing, zero issues
 
-1. Run `make fmt`.
-2. Run `make check`. It runs the tests and the linter in Docker, then the format
-   check. All three must pass with no findings.
+Never run `go test`, `golangci-lint` or `gofmt` directly; use the `make`
+targets.
 
-Never run `go test`, `golangci-lint` or `gofmt` directly. Use the `make` targets
-instead, such as `make test` and `make lint`.
+No commit lands on main with lint errors, test failures, or formatting issues.
 
-## Branches and pull requests
+## Code Style
 
-- Never commit to `main` or `next` directly. Every change is a pull request from
-  a feature branch into `next`.
-- Only the owner merges `next` into `main`.
-- A pull request that closes an issue has the title `Description (closes #N)`.
-- One logical change per commit.
-- Commit messages are in the imperative mood and short.
+- Follow CONVENTIONS.md exactly — it defines the architecture
+- All exported types, functions, methods, and vars must have doc comments
+- All packages must have a package doc comment
+- JSON tags use camelCase (not snake_case)
+- No magic numbers — use named constants
+- No inline error handling (`if err := ...; err != nil`) — use plain assignment
+- Blank line before every `return` statement
+- Blank line separating embedded fields from regular fields in structs
+- Blank imports must have a justification comment
 
-## Code style
+## Git Workflow
 
-- Follow `CONVENTIONS.md`.
-- Outside test files, every package has a package doc comment.
-- Outside test files, every exported type, function and variable has a doc
-  comment.
-- JSON tags are camelCase. The HTTP API's `last_id`, `pow_token` and
-  `hashcash_bits` stay as they are, each with a `//nolint:tagliatelle` comment.
-- Prefer named constants to magic numbers. The `mnd` linter checks for them
-  outside test files.
-- No inline error handling such as `if err := f(); err != nil`. Assign the error
-  on its own line, then test it.
-- A `return` that follows another statement in its block has a blank line before
-  it.
-- A blank line between the embedded fields of a struct and its other fields.
-- Outside test files, every blank import has a comment saying why it is there.
+- **Never commit directly to main** — all changes go on feature branches
+- Merge to main only when ready and passing all checks
+- PR titles: `Description (closes #N)` when closing an issue
+- One logical change per commit
+- Commit messages: imperative mood, concise
 
 ## Architecture
 
-- The server uses `go.uber.org/fx` for dependency injection.
-  `cmd/neoircd/main.go` lists its `fx` providers, such as `db.New` and
-  `handlers.New`.
-- Application packages live under `internal/`, one package per concern.
-- `pkg/irc` holds the IRC command names and numeric reply codes.
-- The `web` package embeds the built web client.
-- Each exported `Handle…` method of `Handlers` returns an `http.HandlerFunc`.
-- A request struct is defined inside the method that decodes it.
-- The server uses the database only through the methods of `db.Database`.
-- The database migrations live in `internal/db/schema/` and are embedded with
-  `go:embed`.
-- The database is SQLite, through the pure Go driver `modernc.org/sqlite`.
+- Dependency injection via Uber fx — all components are fx providers
+- `internal/` for all application packages — one package per concern
+- Handlers return `http.HandlerFunc` using the closure pattern
+- Request/response structs defined inside handler closures
+- Models embed `models.Base` for database access to relation methods
+- Database migrations in `internal/db/schema/` — embedded via `go:embed`
+- SQLite by default (pure Go driver: modernc.org/sqlite)
 
 ## Testing
 
-- Prefer table-driven tests.
-- Use `testing.T` helpers, not assertion libraries.
-- A test file lives next to the code it tests and ends in `_test.go`.
-- The linter requires each test file to be in the package's external test
-  package, such as `handlers_test`. It allows `export_test.go` and files ending
-  in `_internal_test.go` in the package itself.
-- An `export_test.go` file gives the external tests access to the package's
-  unexported code.
+- Table-driven tests preferred
+- Use `testing.T` helpers, not assertion libraries
+- Test files live next to the code they test
+- `_test.go` suffix, same package for white-box testing
 
 ## Dependencies
 
-- The required libraries are listed in `CONVENTIONS.md` §1.
-- No new dependency without a reason given in the pull request.
-- Prefer dependencies written in pure Go, which build without cgo.
+- Required libraries are listed in CONVENTIONS.md §1
+- No new dependencies without justification
+- Pure Go preferred (no CGO)

README.md

@@ -2611,7 +2611,7 @@ listener.
 | Variable               | Type   | Default                                                                                | Description                                                                                                                                                                                                                                                                             |
 | ---------------------- | ------ | -------------------------------------------------------------------------------------- | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
 | `PORT`                 | int    | `8080`                                                                                 | HTTP listen port                                                                                                                                                                                                                                                                        |
-| `DBURL`                | string | `file:///var/lib/neoirc/state.db?_pragma=journal_mode(WAL)&_pragma=busy_timeout(5000)` | SQLite connection string. For file-based: `file:///path/to/db.db?_pragma=journal_mode(WAL)&_pragma=busy_timeout(5000)`. For in-memory (testing): `file::memory:?cache=shared`. It must not set `foreign_keys`. See [SQLite Considerations](#sqlite-considerations).                     |
+| `DBURL`                | string | `file:///var/lib/neoirc/state.db?_pragma=journal_mode(WAL)&_pragma=busy_timeout(5000)` | SQLite connection string. For file-based: `file:///path/to/db.db?_pragma=journal_mode(WAL)&_pragma=busy_timeout(5000)`. For in-memory (testing): `file::memory:?cache=shared`. See [SQLite Considerations](#sqlite-considerations).                                                     |
 | `DEBUG`                | bool   | `false`                                                                                | Switch logging to debug level                                                                                                                                                                                                                                                           |
 | `MESSAGE_MAX_AGE`      | string | `720h`                                                                                 | Maximum age of messages as a Go duration string (e.g. `720h`, `24h`). Messages older than this are pruned. Default is 30 days.                                                                                                                                                          |
 | `SESSION_IDLE_TIMEOUT` | string | `720h`                                                                                 | Idle timeout as a Go duration string (e.g. `720h`, `24h`). Clients with no authenticated HTTP API request or IRC listener command for this long are removed, and a session left with none is expired and its nick released (see [Data Lifecycle](#data-lifecycle)). Default is 30 days. |
@@ -3342,7 +3342,6 @@ neoirc/
 │   │   └── schema/
 │   │       ├── 000.sql     # schema_migrations bootstrap
 │   │       └── 001_initial.sql
-│   ├── dbtest/             # Gives each test its own database; only tests import it
 │   ├── globals/            # Application-wide metadata
 │   │   └── globals.go
 │   ├── handlers/           # HTTP request handlers

internal/db/db.go

@@ -5,11 +5,9 @@ import (
 	"context"
 	"database/sql"
 	"embed"
-	"errors"
 	"fmt"
 	"io/fs"
 	"log/slog"
-	"net/url"
 	"sort"
 	"strconv"
 	"strings"
@@ -24,10 +22,6 @@ import (
 
 const minMigrationParts = 2
 
-var errForeignKeysInDBURL = errors.New(
-	"DBURL must not set foreign_keys, which the server always turns on",
-)
-
 // SchemaFiles contains embedded SQL migration files.
 //
 //go:embed schema/*.sql
@@ -97,27 +91,11 @@ func (database *Database) connect(ctx context.Context) error {
 	}
 
 	// SQLite keeps the foreign keys setting per connection. The driver
-	// runs each _pragma parameter on every connection it opens. So the
-	// one added below also covers the connection the pool opens after
-	// a cancelled query breaks the old one. A foreign_keys pragma in
-	// DBURL could undo it, because the driver sorts the pragmas.
-	_, query, hasQuery := strings.Cut(dbURL, "?")
-
-	urlParams, err := url.ParseQuery(query)
-	if err != nil {
-		return fmt.Errorf("parse DBURL: %w", err)
-	}
-
-	for _, pragma := range urlParams["_pragma"] {
-		if strings.Contains(strings.ToLower(pragma), "foreign_keys") {
-			return fmt.Errorf(
-				"%w: _pragma=%s", errForeignKeysInDBURL, pragma,
-			)
-		}
-	}
-
+	// runs each _pragma parameter on every connection it opens. A
+	// PRAGMA run once would miss the connection the pool opens after a
+	// cancelled query breaks the old one.
 	separator := "?"
-	if hasQuery {
+	if strings.Contains(dbURL, "?") {
 		separator = "&"
 	}
 

internal/db/db_test.go

@@ -3,7 +3,6 @@ package db_test
 import (
 	"context"
 	"errors"
-	"net/url"
 	"path/filepath"
 	"strings"
 	"testing"
@@ -12,7 +11,6 @@ import (
 	"go.uber.org/fx/fxtest"
 	"sneak.berlin/go/neoirc/internal/config"
 	"sneak.berlin/go/neoirc/internal/db"
-	"sneak.berlin/go/neoirc/internal/dbtest"
 	"sneak.berlin/go/neoirc/internal/globals"
 	"sneak.berlin/go/neoirc/internal/logger"
 )
@@ -91,10 +89,8 @@ func TestDefaultDBURLSetsWALAndBusyTimeout(t *testing.T) {
 
 // TestForeignKeysOnAfterCancelledQuery cancels a query while it
 // runs, which makes the pool close its only connection and open a
-// new one. A TEMP table lasts only as long as its connection, so
-// its absence shows the connection was replaced. The test then
-// checks that the file database keeps its tables and that the new
-// connection has foreign keys on.
+// new one. It checks that the file database keeps its tables and
+// that the new connection has foreign keys on.
 func TestForeignKeysOnAfterCancelledQuery(t *testing.T) {
 	t.Parallel()
 
@@ -112,18 +108,26 @@ func TestForeignKeysOnAfterCancelledQuery(t *testing.T) {
 			dbURL := "file://" +
 				filepath.Join(t.TempDir(), "state.db") + params
 
-			database, err := startDatabase(t, dbURL)
+			lifecycle := fxtest.NewLifecycle(t)
+
+			log, err := logger.New(lifecycle, logger.Params{
+				Globals: &globals.Globals{},
+			})
 			if err != nil {
 				t.Fatal(err)
 			}
 
-			_, err = database.GetDB().ExecContext(
-				t.Context(), "CREATE TEMP TABLE first_connection (x)",
-			)
+			database, err := db.New(lifecycle, db.Params{
+				Logger: log,
+				Config: &config.Config{DBURL: dbURL},
+			})
 			if err != nil {
 				t.Fatal(err)
 			}
 
+			lifecycle.RequireStart()
+			t.Cleanup(lifecycle.RequireStop)
+
 			ctx, cancel := context.WithTimeout(
 				t.Context(), endlessQueryTimeout,
 			)
@@ -134,145 +138,32 @@ func TestForeignKeysOnAfterCancelledQuery(t *testing.T) {
 				t.Fatalf("endless query: err = %v", err)
 			}
 
-			tempTables := queryInt(
-				t, database, "SELECT COUNT(*) FROM sqlite_temp_schema",
-			)
-			if tempTables != 0 {
-				t.Fatal("the pool kept its first connection")
+			var migrations int
+
+			err = database.GetDB().QueryRowContext(
+				t.Context(),
+				"SELECT COUNT(*) FROM schema_migrations",
+			).Scan(&migrations)
+			if err != nil {
+				t.Fatal(err)
 			}
 
-			migrations := queryInt(
-				t, database, "SELECT COUNT(*) FROM schema_migrations",
-			)
 			if migrations == 0 {
 				t.Error("schema_migrations is empty")
 			}
 
-			foreignKeys := queryInt(t, database, "PRAGMA foreign_keys")
+			var foreignKeys int
+
+			err = database.GetDB().QueryRowContext(
+				t.Context(), "PRAGMA foreign_keys",
+			).Scan(&foreignKeys)
+			if err != nil {
+				t.Fatal(err)
+			}
+
 			if foreignKeys != 1 {
 				t.Errorf("foreign_keys = %d, want 1", foreignKeys)
 			}
 		})
 	}
 }
-
-// TestNewURLKeepsDataAfterCancelledQuery cancels a query on a test
-// database while it runs, which makes the pool close its only
-// connection and open a new one. A TEMP table lasts only as long as
-// its connection, so its absence shows the connection was replaced.
-// The database must still have its tables and rows.
-func TestNewURLKeepsDataAfterCancelledQuery(t *testing.T) {
-	t.Parallel()
-
-	database, err := startDatabase(t, dbtest.NewURL(t))
-	if err != nil {
-		t.Fatal(err)
-	}
-
-	_, err = database.GetOrCreateChannel(t.Context(), "#test")
-	if err != nil {
-		t.Fatal(err)
-	}
-
-	_, err = database.GetDB().ExecContext(
-		t.Context(), "CREATE TEMP TABLE first_connection (x)",
-	)
-	if err != nil {
-		t.Fatal(err)
-	}
-
-	ctx, cancel := context.WithTimeout(t.Context(), endlessQueryTimeout)
-	defer cancel()
-
-	_, err = database.GetDB().ExecContext(ctx, endlessQuery)
-	if !errors.Is(err, context.DeadlineExceeded) {
-		t.Fatalf("endless query: err = %v", err)
-	}
-
-	tempTables := queryInt(
-		t, database, "SELECT COUNT(*) FROM sqlite_temp_schema",
-	)
-	if tempTables != 0 {
-		t.Fatal("the pool kept its first connection")
-	}
-
-	channels := queryInt(t, database, "SELECT COUNT(*) FROM channels")
-	if channels != 1 {
-		t.Errorf("channels = %d, want 1", channels)
-	}
-}
-
-// TestDBURLSettingForeignKeysFailsStartup checks that the database
-// refuses to start when DBURL sets foreign_keys itself, however it
-// is spelled.
-func TestDBURLSettingForeignKeysFailsStartup(t *testing.T) {
-	t.Parallel()
-
-	pragmas := []string{
-		"foreign_keys(0)",
-		"foreign_keys(off)",
-		"foreign_keys=0",
-		"FOREIGN_KEYS(FALSE)",
-		" Foreign_Keys = 1",
-	}
-
-	for _, pragma := range pragmas {
-		t.Run(pragma, func(t *testing.T) {
-			t.Parallel()
-
-			dbURL := "file://" +
-				filepath.Join(t.TempDir(), "state.db") +
-				"?_pragma=" + url.QueryEscape(pragma)
-
-			_, err := startDatabase(t, dbURL)
-			if err == nil {
-				t.Fatal("the database started")
-			}
-
-			if !strings.Contains(err.Error(), "DBURL") {
-				t.Errorf("error %q does not name DBURL", err)
-			}
-		})
-	}
-}
-
-// 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) {
-	t.Helper()
-
-	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: dbURL},
-	})
-	if err != nil {
-		t.Fatal(err)
-	}
-
-	t.Cleanup(lifecycle.RequireStop)
-
-	return database, lifecycle.Start(t.Context())
-}
-
-// queryInt runs a query that returns a single number.
-func queryInt(t *testing.T, database *db.Database, query string) int {
-	t.Helper()
-
-	var result int
-
-	err := database.GetDB().QueryRowContext(t.Context(), query).Scan(&result)
-	if err != nil {
-		t.Fatal(err)
-	}
-
-	return result
-}

internal/db/export_test.go

@@ -5,16 +5,21 @@ import (
 	"database/sql"
 	"fmt"
 	"log/slog"
-	"testing"
-
-	"sneak.berlin/go/neoirc/internal/dbtest"
+	"sync/atomic"
 )
 
-// NewTestDatabase creates an in-memory database for testing.
-func NewTestDatabase(tb testing.TB) (*Database, error) {
-	tb.Helper()
+//nolint:gochecknoglobals // test counter
+var testDBCounter atomic.Int64
 
-	dsn := dbtest.NewURL(tb) + "&_pragma=foreign_keys(1)"
+// NewTestDatabase creates an in-memory database for testing.
+func NewTestDatabase() (*Database, error) {
+	counter := testDBCounter.Add(1)
+
+	dsn := fmt.Sprintf(
+		"file:testdb%d?mode=memory"+
+			"&cache=shared&_pragma=foreign_keys(1)",
+		counter,
+	)
 
 	conn, err := sql.Open("sqlite", dsn)
 	if err != nil {

internal/db/queries_test.go

@@ -13,7 +13,7 @@ import (
 func setupTestDB(t *testing.T) *db.Database {
 	t.Helper()
 
-	database, err := db.NewTestDatabase(t)
+	database, err := db.NewTestDatabase()
 	if err != nil {
 		t.Fatal(err)
 	}

internal/dbtest/dbtest.go

@@ -1,39 +0,0 @@
-// Package dbtest gives each test a database of its own. Only tests
-// may import it.
-package dbtest
-
-import (
-	"crypto/rand"
-	"database/sql"
-	"testing"
-
-	_ "modernc.org/sqlite" // registers the sqlite driver
-)
-
-// NewURL returns the URL of a new, empty in-memory database for one
-// test. SQLite deletes an in-memory database when its last connection
-// closes. A pool closes a connection when a query on it is cancelled
-// while it runs. So this function holds a connection of its own open
-// until the test ends.
-func NewURL(tb testing.TB) string {
-	tb.Helper()
-
-	// A random name, so that no other test can share the database.
-	dbURL := "file:" + rand.Text() + "?mode=memory&cache=shared"
-
-	pool, err := sql.Open("sqlite", dbURL)
-	if err != nil {
-		tb.Fatalf("open test database: %v", err)
-	}
-
-	tb.Cleanup(func() { _ = pool.Close() })
-
-	conn, err := pool.Conn(tb.Context())
-	if err != nil {
-		tb.Fatalf("connect to test database: %v", err)
-	}
-
-	tb.Cleanup(func() { _ = conn.Close() })
-
-	return dbURL
-}

internal/handlers/api_test.go

@@ -3,6 +3,7 @@ package handlers_test
 import (
 	"bytes"
 	"context"
+	"crypto/rand"
 	"database/sql"
 	"encoding/json"
 	"errors"
@@ -27,7 +28,6 @@ import (
 	api "sneak.berlin/go/neoirc/internal/cli/api"
 	"sneak.berlin/go/neoirc/internal/config"
 	"sneak.berlin/go/neoirc/internal/db"
-	"sneak.berlin/go/neoirc/internal/dbtest"
 	"sneak.berlin/go/neoirc/internal/globals"
 	"sneak.berlin/go/neoirc/internal/handlers"
 	"sneak.berlin/go/neoirc/internal/hashcash"
@@ -164,7 +164,13 @@ func newTestServerWith(
 	viperMu.Lock()
 	defer viperMu.Unlock()
 
-	dbURL := dbtest.NewURL(t)
+	// A random name, so that no other test can share it, not
+	// even one that has finished but still holds its database
+	// open.
+	dbURL := fmt.Sprintf(
+		"file:%s?mode=memory&cache=shared",
+		rand.Text(),
+	)
 	copyTemplateDB(t, dbURL)
 
 	var (

internal/ircserver/server_test.go

@@ -3,6 +3,7 @@ package ircserver_test
 import (
 	"bufio"
 	"context"
+	"crypto/rand"
 	"database/sql"
 	"errors"
 	"fmt"
@@ -19,7 +20,6 @@ import (
 	"sneak.berlin/go/neoirc/internal/broker"
 	"sneak.berlin/go/neoirc/internal/config"
 	"sneak.berlin/go/neoirc/internal/db"
-	"sneak.berlin/go/neoirc/internal/dbtest"
 	"sneak.berlin/go/neoirc/internal/globals"
 	"sneak.berlin/go/neoirc/internal/ircserver"
 	"sneak.berlin/go/neoirc/internal/logger"
@@ -107,7 +107,14 @@ func newTestEnvWithResolver(
 ) *testEnv {
 	t.Helper()
 
-	conn, err := sql.Open("sqlite", dbtest.NewURL(t))
+	// A random name, so that no other test environment, not
+	// even an earlier run of the same test, can share it.
+	dsn := fmt.Sprintf(
+		"file:%s?mode=memory&cache=shared",
+		rand.Text(),
+	)
+
+	conn, err := sql.Open("sqlite", dsn)
 	if err != nil {
 		t.Fatalf("open db: %v", err)
 	}
@@ -137,6 +144,20 @@ func newTestEnvWithResolver(
 
 	brk := broker.New()
 
+	var listenConfig net.ListenConfig
+
+	listener, err := listenConfig.Listen(t.Context(), "tcp", "127.0.0.1:0")
+	if err != nil {
+		t.Fatalf("listen: %v", err)
+	}
+
+	addr := listener.Addr().String()
+
+	err = listener.Close()
+	if err != nil {
+		t.Fatalf("close listener: %v", err)
+	}
+
 	log := slog.New(slog.NewTextHandler(
 		os.Stderr,
 		&slog.HandlerOptions{Level: slog.LevelError}, //nolint:exhaustruct
@@ -146,9 +167,7 @@ func newTestEnvWithResolver(
 		log, cfg, database, brk, interval, deadline, resolve,
 	)
 
-	// Port 0 makes the system pick a free port. dial reads it
-	// back from the server's listener.
-	err = srv.Start("127.0.0.1:0")
+	err = srv.Start(addr)
 	if err != nil {
 		t.Fatalf("start irc server: %v", err)
 	}

internal/server/export_test.go

@@ -15,12 +15,6 @@ func NewTestSPAServer() *Server {
 	return srv
 }
 
-// Listener returns the listener the start hook bound for the
-// HTTP server.
-func (srv *Server) Listener() net.Listener {
-	return srv.listener
-}
-
 // ServeUntilShutdown runs serveUntilShutdown, which serves the
 // HTTP server on listener, and returns when it does.
 func (srv *Server) ServeUntilShutdown(listener net.Listener) {

internal/server/server.go

@@ -50,7 +50,6 @@ type Server struct {
 	sentryEnabled bool
 	log           *slog.Logger
 	httpServer    *http.Server
-	listener      net.Listener
 	router        *chi.Mux
 	params        Params
 	mw            *middleware.Middleware
@@ -180,8 +179,6 @@ func (srv *Server) startHTTP(ctx context.Context) error {
 		return fmt.Errorf("http listen: %w", err)
 	}
 
-	srv.listener = listener
-
 	srv.httpServer = &http.Server{ //nolint:exhaustruct // optional fields
 		Addr:           listenAddr,
 		ReadTimeout:    httpReadTimeout,

internal/server/server_test.go

@@ -5,6 +5,7 @@
 package server_test
 
 import (
+	"crypto/rand"
 	"fmt"
 	"net"
 	"net/http"
@@ -18,7 +19,6 @@ import (
 	"sneak.berlin/go/neoirc/internal/broker"
 	"sneak.berlin/go/neoirc/internal/config"
 	"sneak.berlin/go/neoirc/internal/db"
-	"sneak.berlin/go/neoirc/internal/dbtest"
 	"sneak.berlin/go/neoirc/internal/globals"
 	"sneak.berlin/go/neoirc/internal/handlers"
 	"sneak.berlin/go/neoirc/internal/healthcheck"
@@ -45,9 +45,10 @@ const (
 // for a long poll the HTTP server is serving to finish, and
 // that the poll gets its response.
 func TestStopWaitsForRequestInProgress(t *testing.T) {
-	var srv *server.Server
+	port := freePort(t)
+	addr := net.JoinHostPort("127.0.0.1", strconv.Itoa(port))
 
-	app, brk, database := startApp(t, fx.Populate(&srv))
+	app, brk, database := startApp(t, port)
 
 	sessionID, _, token, err := database.CreateSession(
 		t.Context(), "poller", "poller", "", "",
@@ -56,12 +57,9 @@ func TestStopWaitsForRequestInProgress(t *testing.T) {
 		t.Fatalf("create session: %v", err)
 	}
 
-	tcpAddr, ok := srv.Listener().Addr().(*net.TCPAddr)
-	if !ok {
-		t.Fatalf("listener address %v is not TCP", srv.Listener().Addr())
-	}
-
-	addr := net.JoinHostPort("127.0.0.1", strconv.Itoa(tcpAddr.Port))
+	waitUntil(t, "the HTTP server to listen", func() bool {
+		return canConnect(t, addr)
+	})
 
 	statuses := make(chan int, 1)
 
@@ -147,7 +145,7 @@ func TestStartFailsWhenHTTPPortIsTaken(t *testing.T) {
 func TestServeFailureStopsApp(t *testing.T) {
 	var srv *server.Server
 
-	app, _, _ := startApp(t, fx.Populate(&srv))
+	app, _, _ := startApp(t, freePort(t), fx.Populate(&srv))
 
 	shutdowns := app.Wait()
 
@@ -170,7 +168,7 @@ func TestServeFailureStopsApp(t *testing.T) {
 func TestServeAfterStopDoesNotStopApp(t *testing.T) {
 	var srv *server.Server
 
-	app, _, _ := startApp(t, fx.Populate(&srv))
+	app, _, _ := startApp(t, freePort(t), fx.Populate(&srv))
 
 	shutdowns := app.Wait()
 
@@ -188,15 +186,16 @@ func TestServeAfterStopDoesNotStopApp(t *testing.T) {
 	}
 }
 
-// startApp starts the app newApp builds, with the HTTP port
-// set to 0, so the system gives the server a free port.
+// startApp starts the app newApp builds, with the HTTP server
+// listening on port.
 func startApp(
 	t *testing.T,
+	port int,
 	options ...fx.Option,
 ) (*fxtest.App, *broker.Broker, *db.Database) {
 	t.Helper()
 
-	app, brk, database := newApp(t, 0, options...)
+	app, brk, database := newApp(t, port, options...)
 
 	app.RequireStart()
 
@@ -242,7 +241,10 @@ func newApp(
 			stats.New,
 		),
 		fx.Decorate(func(cfg *config.Config) *config.Config {
-			cfg.DBURL = dbtest.NewURL(t)
+			// A random name, so that no other test can share it.
+			cfg.DBURL = fmt.Sprintf(
+				"file:%s?mode=memory&cache=shared", rand.Text(),
+			)
 			cfg.Port = port
 
 			return cfg
@@ -255,6 +257,21 @@ func newApp(
 	return app, brk, database
 }
 
+// freePort returns a TCP port that nothing was listening on a
+// moment ago.
+func freePort(t *testing.T) int {
+	t.Helper()
+
+	listener := closedListener(t)
+
+	tcpAddr, ok := listener.Addr().(*net.TCPAddr)
+	if !ok {
+		t.Fatalf("listener address %v is not TCP", listener.Addr())
+	}
+
+	return tcpAddr.Port
+}
+
 // closedListener returns a TCP listener that has already been
 // closed, so that accepting a connection on it fails.
 func closedListener(t *testing.T) net.Listener {
@@ -277,6 +294,22 @@ func closedListener(t *testing.T) net.Listener {
 	return listener
 }
 
+// canConnect reports whether addr accepts a TCP connection.
+func canConnect(t *testing.T, addr string) bool {
+	t.Helper()
+
+	var dialer net.Dialer
+
+	conn, err := dialer.DialContext(t.Context(), "tcp", addr)
+	if err != nil {
+		return false
+	}
+
+	_ = conn.Close()
+
+	return true
+}
+
 // waitUntil calls done every checkStep until it returns true,
 // and fails the test if it does not within testTimeout.
 func waitUntil(t *testing.T, what string, done func() bool) {

internal/service/service_test.go

@@ -6,6 +6,7 @@ package service_test
 
 import (
 	"context"
+	"crypto/rand"
 	"encoding/json"
 	"errors"
 	"fmt"
@@ -22,7 +23,6 @@ import (
 	"sneak.berlin/go/neoirc/internal/broker"
 	"sneak.berlin/go/neoirc/internal/config"
 	"sneak.berlin/go/neoirc/internal/db"
-	"sneak.berlin/go/neoirc/internal/dbtest"
 	"sneak.berlin/go/neoirc/internal/globals"
 	"sneak.berlin/go/neoirc/internal/hashcash"
 	"sneak.berlin/go/neoirc/internal/logger"
@@ -46,7 +46,13 @@ type testEnv struct {
 func newTestEnv(t *testing.T) *testEnv {
 	t.Helper()
 
-	dbURL := dbtest.NewURL(t)
+	// A random name, so that no other test can share it, not
+	// even one that has finished but still holds its database
+	// open.
+	dbURL := fmt.Sprintf(
+		"file:%s?mode=memory&cache=shared",
+		rand.Text(),
+	)
 
 	var (
 		database *db.Database