fs storage

pkg/storage/fs/fs_test.go

@@ -0,0 +1,529 @@
+package fs
+
+import (
+	"errors"
+	"os"
+	"path/filepath"
+	"reflect"
+	"strings"
+	"sync/atomic"
+	"testing"
+	"time"
+
+	"galaxy/model/client"
+	"galaxy/model/order"
+	"galaxy/model/report"
+)
+
+const testTimeout = time.Second
+
+type callbackResult[T any] struct {
+	value T
+	err   error
+}
+
+func TestStateRoundTripAsync(t *testing.T) {
+	s := newTestStorage(t)
+	want := sampleState()
+
+	saveDone := make(chan error, 1)
+	s.SaveState(want, func(err error) {
+		saveDone <- err
+	})
+	if err := waitError(t, saveDone); err != nil {
+		t.Fatalf("save state: %v", err)
+	}
+
+	existsDone := make(chan callbackResult[bool], 1)
+	s.StateExists(func(ok bool, err error) {
+		existsDone <- callbackResult[bool]{value: ok, err: err}
+	})
+	exists := waitResult(t, existsDone)
+	if exists.err != nil {
+		t.Fatalf("state exists: %v", exists.err)
+	}
+	if !exists.value {
+		t.Fatal("state file should exist after save")
+	}
+
+	loadDone := make(chan callbackResult[client.State], 1)
+	s.LoadState(func(state client.State, err error) {
+		loadDone <- callbackResult[client.State]{value: state, err: err}
+	})
+	got := waitResult(t, loadDone)
+	if got.err != nil {
+		t.Fatalf("load state: %v", got.err)
+	}
+	if !reflect.DeepEqual(got.value, want) {
+		t.Fatalf("loaded state mismatch\nwant: %#v\ngot:  %#v", want, got.value)
+	}
+}
+
+func TestReportAndOrderRoundTripAsync(t *testing.T) {
+	s := newTestStorage(t)
+	id := client.GameID("game-1")
+	turn := uint(7)
+	initialReport := sampleReport(turn, "Terran")
+	updatedReport := sampleReport(turn, "Zenith")
+	wantOrder := sampleOrder()
+
+	saveReportDone := make(chan error, 1)
+	s.SaveReport(id, turn, initialReport, func(err error) {
+		saveReportDone <- err
+	})
+	if err := waitError(t, saveReportDone); err != nil {
+		t.Fatalf("save report: %v", err)
+	}
+
+	saveOrderDone := make(chan error, 1)
+	s.SaveOrder(id, turn, wantOrder, func(err error) {
+		saveOrderDone <- err
+	})
+	if err := waitError(t, saveOrderDone); err != nil {
+		t.Fatalf("save order: %v", err)
+	}
+
+	saveUpdatedReportDone := make(chan error, 1)
+	s.SaveReport(id, turn, updatedReport, func(err error) {
+		saveUpdatedReportDone <- err
+	})
+	if err := waitError(t, saveUpdatedReportDone); err != nil {
+		t.Fatalf("save updated report: %v", err)
+	}
+
+	loadReportDone := make(chan callbackResult[report.Report], 1)
+	s.LoadReport(id, turn, func(rep report.Report, err error) {
+		loadReportDone <- callbackResult[report.Report]{value: rep, err: err}
+	})
+	gotReport := waitResult(t, loadReportDone)
+	if gotReport.err != nil {
+		t.Fatalf("load report: %v", gotReport.err)
+	}
+	if !reflect.DeepEqual(gotReport.value, updatedReport) {
+		t.Fatalf("loaded report mismatch\nwant: %#v\ngot:  %#v", updatedReport, gotReport.value)
+	}
+
+	loadOrderDone := make(chan callbackResult[order.Order], 1)
+	s.LoadOrder(id, turn, func(got order.Order, err error) {
+		loadOrderDone <- callbackResult[order.Order]{value: got, err: err}
+	})
+	gotOrder := waitResult(t, loadOrderDone)
+	if gotOrder.err != nil {
+		t.Fatalf("load order: %v", gotOrder.err)
+	}
+	if !reflect.DeepEqual(gotOrder.value, wantOrder) {
+		t.Fatalf("loaded order mismatch\nwant: %#v\ngot:  %#v", wantOrder, gotOrder.value)
+	}
+}
+
+func TestSaveOrderBeforeReportReturnsNotExist(t *testing.T) {
+	s := newTestStorage(t)
+
+	done := make(chan error, 1)
+	s.SaveOrder("game-2", 3, sampleOrder(), func(err error) {
+		done <- err
+	})
+	err := waitError(t, done)
+	if !errors.Is(err, os.ErrNotExist) {
+		t.Fatalf("save order error = %v, want os.ErrNotExist", err)
+	}
+}
+
+func TestRawFileCRUDAndList(t *testing.T) {
+	s := newTestStorage(t)
+
+	if err := s.WriteFile("/nested/alpha.txt", []byte("alpha")); err != nil {
+		t.Fatalf("write alpha: %v", err)
+	}
+	if err := s.WriteFile("beta.txt", []byte("beta")); err != nil {
+		t.Fatalf("write beta: %v", err)
+	}
+
+	alphaExists, err := s.FileExists("nested/alpha.txt")
+	if err != nil {
+		t.Fatalf("file exists: %v", err)
+	}
+	if !alphaExists {
+		t.Fatal("nested/alpha.txt should exist")
+	}
+
+	alphaData, err := s.ReadFile("nested/alpha.txt")
+	if err != nil {
+		t.Fatalf("read alpha: %v", err)
+	}
+	if string(alphaData) != "alpha" {
+		t.Fatalf("read alpha = %q, want %q", alphaData, "alpha")
+	}
+
+	if err := os.WriteFile(filepath.Join(s.storageRoot, "skip.txt"+newFileSuffix), []byte("tmp"), 0o644); err != nil {
+		t.Fatalf("create stale .new file: %v", err)
+	}
+	if err := os.WriteFile(filepath.Join(s.storageRoot, "skip.txt"+oldFileSuffix), []byte("tmp"), 0o644); err != nil {
+		t.Fatalf("create stale .old file: %v", err)
+	}
+
+	files, err := s.ListFiles()
+	if err != nil {
+		t.Fatalf("list files: %v", err)
+	}
+	wantFiles := []string{
+		"beta.txt",
+		filepath.Join("nested", "alpha.txt"),
+	}
+	if !reflect.DeepEqual(files, wantFiles) {
+		t.Fatalf("listed files mismatch\nwant: %#v\ngot:  %#v", wantFiles, files)
+	}
+
+	if err := s.DeleteFile("beta.txt"); err != nil {
+		t.Fatalf("delete beta: %v", err)
+	}
+	if err := s.DeleteFile("beta.txt"); !errors.Is(err, os.ErrNotExist) {
+		t.Fatalf("delete missing beta error = %v, want os.ErrNotExist", err)
+	}
+}
+
+func TestPathTraversalRejected(t *testing.T) {
+	s := newTestStorage(t)
+
+	for _, path := range []string{"../escape.txt", "..\\escape.txt", ""} {
+		t.Run(path, func(t *testing.T) {
+			err := s.WriteFile(path, []byte("blocked"))
+			if err == nil {
+				t.Fatalf("write %q unexpectedly succeeded", path)
+			}
+		})
+	}
+}
+
+func TestAtomicWriteFirstAndOverwrite(t *testing.T) {
+	s := newTestStorage(t)
+	target := filepath.Join("turns", "12.bin")
+
+	if err := s.WriteFile(target, []byte("first")); err != nil {
+		t.Fatalf("first write: %v", err)
+	}
+	assertFileContent(t, s, target, "first")
+	assertNoTempArtifacts(t, s, target)
+
+	if err := s.WriteFile(target, []byte("second")); err != nil {
+		t.Fatalf("overwrite: %v", err)
+	}
+	assertFileContent(t, s, target, "second")
+	assertNoTempArtifacts(t, s, target)
+}
+
+func TestAtomicWriteStaleTempCollision(t *testing.T) {
+	t.Run("stale new file", func(t *testing.T) {
+		s := newTestStorage(t)
+		target := "collision-new.txt"
+		absTarget, err := s.resolvePath(target)
+		if err != nil {
+			t.Fatalf("resolve target: %v", err)
+		}
+		if err := os.MkdirAll(filepath.Dir(absTarget), os.ModePerm); err != nil {
+			t.Fatalf("create parent dir: %v", err)
+		}
+		if err := os.WriteFile(absTarget+newFileSuffix, []byte("stale"), 0o644); err != nil {
+			t.Fatalf("write stale new file: %v", err)
+		}
+
+		err = s.WriteFile(target, []byte("payload"))
+		if err == nil || !strings.Contains(err.Error(), "new file already exists") {
+			t.Fatalf("write error = %v, want stale new file error", err)
+		}
+	})
+
+	t.Run("stale old file", func(t *testing.T) {
+		s := newTestStorage(t)
+		target := "collision-old.txt"
+		absTarget, err := s.resolvePath(target)
+		if err != nil {
+			t.Fatalf("resolve target: %v", err)
+		}
+		if err := os.WriteFile(absTarget, []byte("current"), 0o644); err != nil {
+			t.Fatalf("write target: %v", err)
+		}
+		if err := os.WriteFile(absTarget+oldFileSuffix, []byte("stale"), 0o644); err != nil {
+			t.Fatalf("write stale old file: %v", err)
+		}
+
+		err = s.WriteFile(target, []byte("payload"))
+		if err == nil || !strings.Contains(err.Error(), "old file already exists") {
+			t.Fatalf("write error = %v, want stale old file error", err)
+		}
+	})
+}
+
+func TestAtomicWriteRollbackOnRenameFailure(t *testing.T) {
+	s := newTestStorage(t)
+	target := filepath.Join("rollback", "state.txt")
+	absTarget, err := s.resolvePath(target)
+	if err != nil {
+		t.Fatalf("resolve target: %v", err)
+	}
+
+	if err := s.WriteFile(target, []byte("original")); err != nil {
+		t.Fatalf("seed target file: %v", err)
+	}
+
+	origRename := s.renameFileFn
+	s.renameFileFn = func(oldPath, newPath string) error {
+		if oldPath == absTarget+newFileSuffix && newPath == absTarget {
+			return errors.New("forced rename failure")
+		}
+		return origRename(oldPath, newPath)
+	}
+
+	err = s.WriteFile(target, []byte("replacement"))
+	if err == nil || !strings.Contains(err.Error(), "forced rename failure") {
+		t.Fatalf("write error = %v, want forced rename failure", err)
+	}
+
+	assertFileContent(t, s, target, "original")
+	assertNoTempArtifacts(t, s, target)
+}
+
+func TestSamePathOperationsSerialize(t *testing.T) {
+	s := newTestStorage(t)
+	target := "shared.txt"
+	absTarget, err := s.resolvePath(target)
+	if err != nil {
+		t.Fatalf("resolve target: %v", err)
+	}
+
+	entered := make(chan struct{})
+	release := make(chan struct{})
+	origWrite := s.writeFileFn
+	var writes atomic.Int32
+	s.writeFileFn = func(path string, data []byte, perm os.FileMode) error {
+		if path == absTarget+newFileSuffix && writes.Add(1) == 1 {
+			close(entered)
+			<-release
+		}
+		return origWrite(path, data, perm)
+	}
+
+	firstDone := make(chan error, 1)
+	go func() {
+		firstDone <- s.WriteFile(target, []byte("one"))
+	}()
+	waitSignal(t, entered, "first write entered")
+
+	secondDone := make(chan error, 1)
+	go func() {
+		secondDone <- s.WriteFile(target, []byte("two"))
+	}()
+
+	select {
+	case err := <-secondDone:
+		t.Fatalf("second write finished before first released: %v", err)
+	case <-time.After(50 * time.Millisecond):
+	}
+	if writes.Load() != 1 {
+		t.Fatalf("same-path write reached file hook %d times before release, want 1", writes.Load())
+	}
+
+	close(release)
+	if err := waitError(t, firstDone); err != nil {
+		t.Fatalf("first write: %v", err)
+	}
+	if err := waitError(t, secondDone); err != nil {
+		t.Fatalf("second write: %v", err)
+	}
+}
+
+func TestDifferentPathOperationsDoNotBlockEachOther(t *testing.T) {
+	s := newTestStorage(t)
+	blockedTarget := "blocked.txt"
+	absTarget, err := s.resolvePath(blockedTarget)
+	if err != nil {
+		t.Fatalf("resolve blocked target: %v", err)
+	}
+
+	entered := make(chan struct{})
+	release := make(chan struct{})
+	origWrite := s.writeFileFn
+	s.writeFileFn = func(path string, data []byte, perm os.FileMode) error {
+		if path == absTarget+newFileSuffix {
+			close(entered)
+			<-release
+		}
+		return origWrite(path, data, perm)
+	}
+
+	blockedDone := make(chan error, 1)
+	go func() {
+		blockedDone <- s.WriteFile(blockedTarget, []byte("blocked"))
+	}()
+	waitSignal(t, entered, "blocked write entered")
+
+	freeDone := make(chan error, 1)
+	go func() {
+		freeDone <- s.WriteFile("free.txt", []byte("free"))
+	}()
+
+	select {
+	case err := <-freeDone:
+		if err != nil {
+			t.Fatalf("free write: %v", err)
+		}
+	case <-time.After(testTimeout):
+		t.Fatal("write for a different path should not block")
+	}
+
+	close(release)
+	if err := waitError(t, blockedDone); err != nil {
+		t.Fatalf("blocked write: %v", err)
+	}
+}
+
+func TestSaveStateIsNonBlockingAndCallbackBased(t *testing.T) {
+	s := newTestStorage(t)
+
+	entered := make(chan struct{})
+	release := make(chan struct{})
+	origWrite := s.writeFileFn
+	s.writeFileFn = func(path string, data []byte, perm os.FileMode) error {
+		close(entered)
+		<-release
+		return origWrite(path, data, perm)
+	}
+
+	callbacks := make(chan error, 2)
+	s.SaveState(sampleState(), func(err error) {
+		callbacks <- err
+	})
+
+	waitSignal(t, entered, "async save entered")
+
+	select {
+	case err := <-callbacks:
+		t.Fatalf("callback fired before storage write completed: %v", err)
+	default:
+	}
+
+	close(release)
+	if err := waitError(t, callbacks); err != nil {
+		t.Fatalf("callback error: %v", err)
+	}
+
+	select {
+	case err := <-callbacks:
+		t.Fatalf("callback fired more than once: %v", err)
+	case <-time.After(50 * time.Millisecond):
+	}
+}
+
+func newTestStorage(t *testing.T) *fsStorage {
+	t.Helper()
+
+	s, err := NewFS(t.TempDir())
+	if err != nil {
+		t.Fatalf("new test storage: %v", err)
+	}
+	return s
+}
+
+func sampleState() client.State {
+	return client.State{
+		GameState: []client.GameState{
+			{ID: client.GameID("game-1"), LastTurn: 12, ActiveTurn: 11},
+			{ID: client.GameID("game-2"), LastTurn: 4, ActiveTurn: 4},
+		},
+		ActiveGameID: client.GameID("game-2"),
+	}
+}
+
+func sampleReport(turn uint, race string) report.Report {
+	return report.Report{
+		Turn:        turn,
+		Width:       160,
+		Height:      90,
+		PlanetCount: 8,
+		Race:        race,
+		VoteFor:     "assembly",
+	}
+}
+
+func sampleOrder() order.Order {
+	return order.Order{
+		UpdatedAt: 1700,
+		Commands: []order.DecodableCommand{
+			&order.CommandPlanetRename{
+				CommandMeta: order.CommandMeta{
+					CmdType: order.CommandTypePlanetRename,
+					CmdID:   "rename-planet",
+				},
+				Number: 2,
+				Name:   "Nova Prime",
+			},
+			&order.CommandRaceVote{
+				CommandMeta: order.CommandMeta{
+					CmdType: order.CommandTypeRaceVote,
+					CmdID:   "vote-race",
+				},
+				Acceptor: "ZENITH",
+			},
+		},
+	}
+}
+
+func assertFileContent(t *testing.T, s *fsStorage, path, want string) {
+	t.Helper()
+
+	got, err := s.ReadFile(path)
+	if err != nil {
+		t.Fatalf("read %q: %v", path, err)
+	}
+	if string(got) != want {
+		t.Fatalf("content for %q = %q, want %q", path, got, want)
+	}
+}
+
+func assertNoTempArtifacts(t *testing.T, s *fsStorage, path string) {
+	t.Helper()
+
+	absPath, err := s.resolvePath(path)
+	if err != nil {
+		t.Fatalf("resolve path %q: %v", path, err)
+	}
+	for _, tempPath := range []string{absPath + newFileSuffix, absPath + oldFileSuffix} {
+		if _, err := os.Stat(tempPath); !errors.Is(err, os.ErrNotExist) {
+			t.Fatalf("temp artifact %q should not exist, stat err = %v", tempPath, err)
+		}
+	}
+}
+
+func waitSignal(t *testing.T, ch <-chan struct{}, name string) {
+	t.Helper()
+
+	select {
+	case <-ch:
+	case <-time.After(testTimeout):
+		t.Fatalf("timeout waiting for %s", name)
+	}
+}
+
+func waitError(t *testing.T, ch <-chan error) error {
+	t.Helper()
+
+	select {
+	case err := <-ch:
+		return err
+	case <-time.After(testTimeout):
+		t.Fatal("timeout waiting for error callback")
+		return nil
+	}
+}
+
+func waitResult[T any](t *testing.T, ch <-chan callbackResult[T]) callbackResult[T] {
+	t.Helper()
+
+	select {
+	case result := <-ch:
+		return result
+	case <-time.After(testTimeout):
+		t.Fatal("timeout waiting for callback result")
+		return callbackResult[T]{}
+	}
+}