updates lists restore flow for replace collisions (#5073)

updates lists restore flow for replace collisions

#### Does this PR need a docs update or release note?

- [ ] ✅ Yes, it's included
- [ ] 🕐 Yes, but in a later PR
- [x] ⛔ No

#### Type of change

<!--- Please check the type of change your PR introduces: --->
- [ ] 🌻 Feature
- [x] 🐛 Bugfix
- [ ] 🗺️ Documentation
- [ ] 🤖 Supportability/Tests
- [ ] 💻 CI/Deployment
- [ ] 🧹 Tech Debt/Cleanup

#### Issue(s)
#4754 

#### Test Plan

<!-- How will this be tested prior to merging.-->
- [x] 💪 Manual
- [x] ⚡ Unit test
- [x] 💚 E2E

src/internal/m365/collection/site/handlers.go

@@ -36,6 +36,7 @@ type getItemser interface {
 
 type restoreHandler interface {
 	PostLister
+	PatchLister
 	DeleteLister
 	GetLister
 	GetListsByCollisionKeyser
@@ -50,6 +51,14 @@ type PostLister interface {
 	) (models.Listable, error)
 }
 
+type PatchLister interface {
+	PatchList(
+		ctx context.Context,
+		listID string,
+		list models.Listable,
+	) (models.Listable, error)
+}
+
 type DeleteLister interface {
 	DeleteList(
 		ctx context.Context,

src/internal/m365/collection/site/lists_handler.go

@@ -73,6 +73,14 @@ func (rh listsRestoreHandler) PostList(
 	return rh.ac.PostList(ctx, rh.protectedResource, listName, storedList, errs)
 }
 
+func (rh listsRestoreHandler) PatchList(
+	ctx context.Context,
+	listID string,
+	list models.Listable,
+) (models.Listable, error) {
+	return rh.ac.PatchList(ctx, rh.protectedResource, listID, list)
+}
+
 func (rh listsRestoreHandler) DeleteList(
 	ctx context.Context,
 	listID string,

src/internal/m365/collection/site/mock/list.go

@@ -95,17 +95,16 @@ func (lh *ListHandler) Check(t *testing.T, expected []string) {
 }
 
 type ListRestoreHandler struct {
-	getListErr    error
 	deleteListErr error
-	postListErrs  []error
-	postListCalls int
+	postListErr   error
+	patchListErr  error
 }
 
-func NewListRestoreHandler(getListErr, deleteListErr error, postListErrs []error) *ListRestoreHandler {
+func NewListRestoreHandler(deleteListErr error, postListErr, patchListErr error) *ListRestoreHandler {
 	return &ListRestoreHandler{
-		getListErr:    getListErr,
 		deleteListErr: deleteListErr,
-		postListErrs:  postListErrs,
+		postListErr:   postListErr,
+		patchListErr:  patchListErr,
 	}
 }
 
@@ -115,15 +114,16 @@ func (lh *ListRestoreHandler) PostList(
 	storedList models.Listable,
 	_ *fault.Bus,
 ) (models.Listable, error) {
-	lh.postListCalls++
-
 	ls, _ := api.ToListable(storedList, listName)
+	return ls, lh.postListErr
+}
 
-	if lh.postListCalls > len(lh.postListErrs) {
-		return ls, nil
-	}
-
-	return nil, lh.postListErrs[lh.postListCalls-1]
+func (lh *ListRestoreHandler) PatchList(
+	ctx context.Context,
+	listID string,
+	list models.Listable,
+) (models.Listable, error) {
+	return nil, lh.patchListErr
 }
 
 func (lh *ListRestoreHandler) GetList(
@@ -133,10 +133,6 @@ func (lh *ListRestoreHandler) GetList(
 	ls := models.NewList()
 	ls.SetId(ptr.To(listID))
 
-	if lh.getListErr != nil {
-		return nil, nil, lh.getListErr
-	}
-
 	return ls, api.ListToSPInfo(ls), nil
 }
 
@@ -148,10 +144,6 @@ func (lh *ListRestoreHandler) GetListsByCollisionKey(ctx context.Context) (map[s
 	return map[string]string{}, nil
 }
 
-func (lh *ListRestoreHandler) CheckPostListCalls(t *testing.T, expectedCalls int) {
-	assert.Equal(t, expectedCalls, lh.postListCalls, "unequal number of post-list calls")
-}
-
 func StubLists(ids ...string) []models.Listable {
 	lists := make([]models.Listable, 0, len(ids))
 

src/internal/m365/collection/site/restore.go

@@ -77,7 +77,7 @@ func restoreListItem(
 			ctr.Inc(count.CollisionSkip)
 			log.Debug("skipping item with collision")
 
-			return dii, core.ErrAlreadyExists
+			return dii, clues.Stack(core.ErrAlreadyExists)
 		}
 
 		collisionID = id
@@ -86,18 +86,19 @@ func restoreListItem(
 	if collisionPolicy != control.Replace {
 		restoredList, err = rh.PostList(ctx, newName, storedList, errs)
 		if err != nil {
-			return dii, clues.WrapWC(ctx, err, "restoring list")
+			return dii, clues.Wrap(err, "restoring list")
 		}
 	} else {
 		restoredList, err = handleListReplace(
 			ctx,
 			collisionID,
 			storedList,
+			newName,
 			rh,
 			ctr,
 			errs)
 		if err != nil {
-			return dii, err
+			return dii, clues.Stack(err)
 		}
 	}
 
@@ -110,42 +111,42 @@ func restoreListItem(
 
 func handleListReplace(
 	ctx context.Context,
-	collisionID string,
-	storedList models.Listable,
+	listID string,
+	listFromBackup models.Listable,
+	newName string,
 	rh restoreHandler,
 	ctr *count.Bus,
 	errs *fault.Bus,
 ) (models.Listable, error) {
-	collidedList, _, err := rh.GetList(ctx, collisionID)
+	restoredList, err := rh.PostList(
+		ctx,
+		newName,
+		listFromBackup,
+		errs)
 	if err != nil {
-		return nil, clues.WrapWC(ctx, err, "fetching collided list")
+		return nil, clues.WrapWC(ctx, err, "restoring list")
 	}
 
-	err = rh.DeleteList(ctx, collisionID)
+	err = rh.DeleteList(ctx, listID)
 	if err != nil {
 		return nil, clues.WrapWC(ctx, err, "deleting collided list")
 	}
 
-	restoredList, err := rh.PostList(
+	patchList := models.NewList()
+	patchList.SetDisplayName(listFromBackup.GetDisplayName())
+	_, err = rh.PatchList(
 		ctx,
-		ptr.Val(storedList.GetDisplayName()),
-		storedList,
-		errs)
-	if err == nil {
-		ctr.Inc(count.CollisionReplace)
-		return restoredList, nil
-	}
+		ptr.Val(restoredList.GetId()),
+		patchList)
 
-	_, collidedListErr := rh.PostList(
-		ctx,
-		ptr.Val(collidedList.GetDisplayName()),
-		collidedList,
-		errs)
-	if collidedListErr != nil {
-		return nil, clues.WrapWC(ctx, collidedListErr, "re-creating collided list")
+	if err != nil {
+		return nil, clues.WrapWC(ctx, err, "patching list")
 	}
 
-	return nil, clues.WrapWC(ctx, err, "restoring list")
+	restoredList.SetDisplayName(listFromBackup.GetDisplayName())
+	ctr.Inc(count.CollisionReplace)
+
+	return restoredList, nil
 }
 
 func RestoreListCollection(