fix: use slash-separated lock paths on Windows (#344)

lib/locksystem_test.go

@@ -0,0 +1,79 @@
+package lib
+
+import (
+	"path"
+	"path/filepath"
+	"testing"
+	"time"
+
+	"github.com/stretchr/testify/require"
+	"golang.org/x/net/webdav"
+)
+
+func TestLockSystemRootLockProtectsDescendants(t *testing.T) {
+	t.Parallel()
+
+	locks := newLockSystem(webdav.NewMemLS(), filepath.Join(t.TempDir(), "nested"))
+	now := time.Now()
+
+	token, err := locks.Create(now, webdav.LockDetails{
+		Root:     "/",
+		Duration: time.Minute,
+	})
+	require.NoError(t, err)
+	t.Cleanup(func() {
+		require.NoError(t, locks.Unlock(time.Now(), token))
+	})
+
+	_, err = locks.Create(now, webdav.LockDetails{
+		Root:      "/child.txt",
+		Duration:  time.Minute,
+		ZeroDepth: true,
+	})
+	require.ErrorIs(t, err, webdav.ErrLocked)
+}
+
+func TestLockSystemSharesLocksAcrossNestedUserDirectories(t *testing.T) {
+	t.Parallel()
+
+	shared := webdav.NewMemLS()
+	parentDirectory := t.TempDir()
+	childDirectory := filepath.Join(parentDirectory, "child")
+	parent := newLockSystem(shared, parentDirectory)
+	child := newLockSystem(shared, childDirectory)
+	now := time.Now()
+
+	token, err := parent.Create(now, webdav.LockDetails{
+		Root:     "/",
+		Duration: time.Minute,
+	})
+	require.NoError(t, err)
+	t.Cleanup(func() {
+		require.NoError(t, parent.Unlock(time.Now(), token))
+	})
+
+	_, err = child.Create(now, webdav.LockDetails{
+		Root:      "/file.txt",
+		Duration:  time.Minute,
+		ZeroDepth: true,
+	})
+	require.ErrorIs(t, err, webdav.ErrLocked)
+
+	// The lock key is slash-separated on every platform, so the child's file
+	// nests under the parent's root lock rather than diverging on Windows.
+	key, err := child.resolve("/file.txt")
+	require.NoError(t, err)
+	require.Equal(t, path.Join(filepath.ToSlash(childDirectory), "file.txt"), key)
+}
+
+func TestMultiDirLockSystemUsesSlashSeparatedKeys(t *testing.T) {
+	t.Parallel()
+
+	mounts := DirectoryMounts{{Name: "docs", Path: filepath.Join(t.TempDir(), "docs")}}
+	locks := newMultiDirLockSystem(webdav.NewMemLS(), mounts)
+
+	key, err := locks.resolve("/docs/report.txt")
+	require.NoError(t, err)
+	require.Equal(t, path.Join(filepath.ToSlash(mounts[0].Path), "report.txt"), key)
+	require.NotContains(t, key, "\\")
+}