feat: drop sqlite support

internal/testutil/postgres_main.go

@@ -0,0 +1,118 @@
+package testutil
+
+import (
+	"database/sql"
+	"fmt"
+	"net"
+	"os"
+	"os/exec"
+	"testing"
+	"time"
+
+	_ "github.com/jackc/pgx/v5/stdlib"
+)
+
+// PostgresMain is the TestMain entry point used by every package whose tests touch
+// the database. It guarantees a running PostgreSQL 17 instance for the duration of
+// the test binary:
+//
+//   - If BUDGIT_TEST_POSTGRES_URL is already set, it is used as-is. CI and `task test`
+//     hit this path.
+//   - Otherwise an ephemeral `postgres:17-alpine` container is started on a free
+//     local port, BUDGIT_TEST_POSTGRES_URL is exported to it for the test process,
+//     and the container is removed when the test binary exits — even on panic, via
+//     a deferred cleanup around m.Run().
+//
+// Usage in each test package:
+//
+//	func TestMain(m *testing.M) { testutil.PostgresMain(m) }
+func PostgresMain(m *testing.M) {
+	if os.Getenv("BUDGIT_TEST_POSTGRES_URL") != "" {
+		os.Exit(m.Run())
+	}
+
+	if _, err := exec.LookPath("docker"); err != nil {
+		fmt.Fprintln(os.Stderr, "testutil.PostgresMain: BUDGIT_TEST_POSTGRES_URL is unset and `docker` is not on PATH; cannot run db tests")
+		os.Exit(1)
+	}
+
+	port, err := freePort()
+	if err != nil {
+		fmt.Fprintf(os.Stderr, "testutil.PostgresMain: failed to find free port: %v\n", err)
+		os.Exit(1)
+	}
+
+	containerName := fmt.Sprintf("budgit-test-pg-%d-%d", os.Getpid(), time.Now().UnixNano())
+
+	startCmd := exec.Command("docker", "run", "--rm", "-d",
+		"--name", containerName,
+		"-p", fmt.Sprintf("%d:5432", port),
+		"-e", "POSTGRES_USER=budgit_test",
+		"-e", "POSTGRES_PASSWORD=testpass",
+		"-e", "POSTGRES_DB=budgit_test",
+		// tmpfs for the data dir keeps tests fast — we don't care about durability.
+		"--tmpfs", "/var/lib/postgresql/data:rw",
+		"postgres:17-alpine",
+	)
+	if out, err := startCmd.CombinedOutput(); err != nil {
+		fmt.Fprintf(os.Stderr, "testutil.PostgresMain: docker run failed: %v\n%s\n", err, out)
+		os.Exit(1)
+	}
+
+	stop := func() {
+		// `docker rm -f` because --rm only fires on a clean exit; force-stop the
+		// container regardless of state so leftover containers don't accumulate.
+		_ = exec.Command("docker", "rm", "-f", containerName).Run()
+	}
+
+	url := fmt.Sprintf("postgres://budgit_test:testpass@127.0.0.1:%d/budgit_test?sslmode=disable", port)
+	if err := waitForPostgres(url, 60*time.Second); err != nil {
+		stop()
+		fmt.Fprintf(os.Stderr, "testutil.PostgresMain: postgres did not become ready: %v\n", err)
+		os.Exit(1)
+	}
+
+	if err := os.Setenv("BUDGIT_TEST_POSTGRES_URL", url); err != nil {
+		stop()
+		fmt.Fprintf(os.Stderr, "testutil.PostgresMain: setenv failed: %v\n", err)
+		os.Exit(1)
+	}
+
+	// Run tests, then ALWAYS stop the container — including on panic.
+	code := func() int {
+		defer stop()
+		return m.Run()
+	}()
+	os.Exit(code)
+}
+
+func freePort() (int, error) {
+	l, err := net.Listen("tcp", "127.0.0.1:0")
+	if err != nil {
+		return 0, err
+	}
+	defer l.Close()
+	return l.Addr().(*net.TCPAddr).Port, nil
+}
+
+// waitForPostgres polls until a real client connection succeeds. pg_isready isn't
+// sufficient under load — under parallel `go test ./...` we've seen it report ready
+// while client connections still fail with "unexpected EOF" because the server is
+// still finishing startup.
+func waitForPostgres(url string, timeout time.Duration) error {
+	deadline := time.Now().Add(timeout)
+	var lastErr error
+	for time.Now().Before(deadline) {
+		db, err := sql.Open("pgx", url)
+		if err == nil {
+			if err = db.Ping(); err == nil {
+				_ = db.Close()
+				return nil
+			}
+			_ = db.Close()
+		}
+		lastErr = err
+		time.Sleep(200 * time.Millisecond)
+	}
+	return fmt.Errorf("timed out after %s: %w", timeout, lastErr)
+}