test(download): reproduce task resurrection after deletion

pkg/download/delete_lifecycle_test.go

@@ -0,0 +1,137 @@
+package download
+
+import (
+	"errors"
+	"fmt"
+	"sync"
+	"testing"
+	"time"
+
+	"github.com/GopeedLab/gopeed/internal/fetcher"
+	"github.com/GopeedLab/gopeed/pkg/base"
+)
+
+type deleteResolveManager struct {
+	*generationTestManager
+	returned chan struct{}
+}
+
+func (m *deleteResolveManager) Build() fetcher.Fetcher {
+	return &deleteResolveFetcher{generationTestFetcher: m.generationTestManager.Build().(*generationTestFetcher), returned: m.returned}
+}
+
+type deleteResolveFetcher struct {
+	*generationTestFetcher
+	returned chan struct{}
+}
+
+func (f *deleteResolveFetcher) Resolve(req *base.Request) error {
+	defer close(f.returned)
+	return f.generationTestFetcher.Resolve(req)
+}
+func waitDeleteTest(t *testing.T, ch <-chan struct{}) {
+	t.Helper()
+	select {
+	case <-ch:
+	case <-time.After(3 * time.Second):
+		t.Fatal("operation did not finish")
+	}
+}
+func TestDeleteDuringResolveCannotRestartOrPersist(t *testing.T) {
+	for _, force := range []bool{false, true} {
+		for _, resolveErr := range []error{nil, errors.New("late resolve error")} {
+			t.Run(fmt.Sprintf("force=%v/error=%v", force, resolveErr != nil), func(t *testing.T) {
+				release := make(chan struct{})
+				var once sync.Once
+				defer once.Do(func() { close(release) })
+				m := &deleteResolveManager{generationTestManager: &generationTestManager{resolveStarted: make(chan struct{}), resolveRelease: release, resolveErr: resolveErr}, returned: make(chan struct{})}
+				d := NewDownloader(&DownloaderConfig{Storage: NewMemStorage(), StorageDir: t.TempDir(), TempDir: t.TempDir(), FetchManagers: []fetcher.FetcherManager{m}})
+				if err := d.Setup(); err != nil {
+					t.Fatal(err)
+				}
+				defer d.Close()
+				id, err := d.CreateDirect(&base.Request{URL: "generation://delete"}, &base.Options{Path: t.TempDir(), Name: "delete.bin"})
+				if err != nil {
+					t.Fatal(err)
+				}
+				waitDeleteTest(t, m.resolveStarted)
+				task := d.GetTask(id)
+				if err := d.Delete(&TaskFilter{IDs: []string{id}}, force); err != nil {
+					t.Fatal(err)
+				}
+				once.Do(func() { close(release) })
+				waitDeleteTest(t, m.returned)
+				task.lock.Lock()
+				task.lock.Unlock()
+				// A stale error callback can run immediately after the startup handler exits.
+				d.doOnError(task, errors.New("late callback"))
+				if got := m.starts.Load(); got != 0 {
+					t.Errorf("deleted task started %d time(s)", got)
+				}
+				if d.GetTask(id) != nil {
+					t.Error("deleted task is still listed")
+				}
+				for _, bucket := range []string{bucketTask, bucketSave, bucketTaskStats} {
+					var value any
+					present, err := d.storage.Get(bucket, id, &value)
+					if err != nil {
+						t.Fatal(err)
+					}
+					if present {
+						t.Errorf("deleted task resurrected in %s", bucket)
+					}
+				}
+			})
+		}
+	}
+}
+
+type blockedTaskStorage struct {
+	Storage
+	entered chan struct{}
+	release chan struct{}
+	blockID string
+	once    sync.Once
+}
+
+func (s *blockedTaskStorage) Put(bucket, key string, value any) error {
+	if bucket == bucketTask && key == s.blockID {
+		s.once.Do(func() { close(s.entered); <-s.release })
+	}
+	return s.Storage.Put(bucket, key, value)
+}
+func TestDeleteSerializesInFlightTaskCheckpoint(t *testing.T) {
+	s := &blockedTaskStorage{Storage: NewMemStorage(), entered: make(chan struct{}), release: make(chan struct{})}
+	d := NewDownloader(&DownloaderConfig{Storage: s, StorageDir: t.TempDir(), TempDir: t.TempDir(), FetchManagers: []fetcher.FetcherManager{&generationTestManager{}}})
+	if err := d.Setup(); err != nil {
+		t.Fatal(err)
+	}
+	defer d.Close()
+	d.cfg.MaxRunning = 0
+	id, err := d.CreateDirect(&base.Request{URL: "generation://checkpoint"}, &base.Options{Path: t.TempDir()})
+	if err != nil {
+		t.Fatal(err)
+	}
+	task := d.GetTask(id)
+	s.blockID = id
+	saved := make(chan struct{})
+	go func() { defer close(saved); _ = d.saveTask(task) }()
+	waitDeleteTest(t, s.entered)
+	deleted := make(chan struct{})
+	go func() { defer close(deleted); _ = d.Delete(&TaskFilter{IDs: []string{id}}, false) }()
+	deadline := time.Now().Add(3 * time.Second)
+	for d.GetTask(id) != nil && time.Now().Before(deadline) {
+		time.Sleep(time.Millisecond)
+	}
+	close(s.release)
+	waitDeleteTest(t, saved)
+	waitDeleteTest(t, deleted)
+	var value any
+	present, err := s.Get(bucketTask, id, &value)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if present {
+		t.Fatal("in-flight checkpoint restored a deleted task")
+	}
+}