extract container transforms from the api layer (#4478)

removes the cache container transformation funcs
from the exchange api container enumeration params. This ensures a cleaner separation of ownership where the api is only responsible for enumerating containers, and the caller is responsible for transforming them.

---

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

- [x] ⛔ No

#### Type of change

- [ ] 🧹 Tech Debt/Cleanup


#### Test Plan

- [x] ⚡ Unit test
- [x] 💚 E2E

src/internal/m365/collection/exchange/backup.go

@@ -21,9 +21,6 @@ import (
 	"github.com/alcionai/corso/src/pkg/services/m365/api"
 )
 
-// CreateCollections - utility function that retrieves M365
-// IDs through Microsoft Graph API. The selectors.ExchangeScope
-// determines the type of collections that are retrieved.
 func CreateCollections(
 	ctx context.Context,
 	bpc inject.BackupProducerConfig,

src/internal/m365/collection/exchange/backup_test.go

@@ -796,53 +796,25 @@ func (suite *BackupIntgSuite) TestContactSerializationRegression() {
 // TestEventsSerializationRegression ensures functionality of createCollections
 // to be able to successfully query, download and restore event objects
 func (suite *BackupIntgSuite) TestEventsSerializationRegression() {
-	t := suite.T()
-
-	ctx, flush := tester.NewContext(t)
-	defer flush()
-
 	var (
 		users    = []string{suite.user}
 		handlers = BackupHandlers(suite.ac)
-		calID    string
-		bdayID   string
 	)
 
-	fn := func(gcc graph.CachedContainer) error {
-		if ptr.Val(gcc.GetDisplayName()) == api.DefaultCalendar {
-			calID = ptr.Val(gcc.GetId())
-		}
-
-		if ptr.Val(gcc.GetDisplayName()) == "Birthdays" {
-			bdayID = ptr.Val(gcc.GetId())
-		}
-
-		return nil
-	}
-
-	err := suite.ac.Events().EnumerateContainers(
-		ctx,
-		suite.user,
-		"",
-		false,
-		fn,
-		fault.New(true))
-	require.NoError(t, err, clues.ToCore(err))
-
 	tests := []struct {
-		name, expected string
-		scope          selectors.ExchangeScope
+		name, expectedContainerName string
+		scope                       selectors.ExchangeScope
 	}{
 		{
-			name:     "Default Event Calendar",
-			expected: calID,
+			name:                  "Default Event Calendar",
+			expectedContainerName: api.DefaultCalendar,
 			scope: selectors.NewExchangeBackup(users).EventCalendars(
 				[]string{api.DefaultCalendar},
 				selectors.PrefixMatch())[0],
 		},
 		{
-			name:     "Birthday Calendar",
-			expected: bdayID,
+			name:                  "Birthday Calendar",
+			expectedContainerName: "Birthdays",
 			scope: selectors.NewExchangeBackup(users).EventCalendars(
 				[]string{"Birthdays"},
 				selectors.PrefixMatch())[0],
@@ -879,13 +851,16 @@ func (suite *BackupIntgSuite) TestEventsSerializationRegression() {
 			wg.Add(len(collections))
 
 			for _, edc := range collections {
+				dlp, isDLP := edc.(data.LocationPather)
+
 				var isMetadata bool
 
-				if edc.FullPath().Service() != path.ExchangeMetadataService {
-					isMetadata = true
-					assert.Equal(t, test.expected, edc.FullPath().Folder(false))
+				if edc.FullPath().Service() == path.ExchangeService {
+					require.True(t, isDLP, "must be a location pather")
+					assert.Contains(t, dlp.LocationPath().Elements(), test.expectedContainerName)
 				} else {
-					assert.Equal(t, "", edc.FullPath().Folder(false))
+					isMetadata = true
+					assert.Empty(t, edc.FullPath().Folder(false))
 				}
 
 				for item := range edc.Items(ctx, fault.New(true)) {

src/internal/m365/collection/exchange/contacts_container_cache.go

@@ -4,6 +4,7 @@ import (
 	"context"
 
 	"github.com/alcionai/clues"
+	"github.com/microsoftgraph/msgraph-sdk-go/models"
 
 	"github.com/alcionai/corso/src/internal/common/ptr"
 	"github.com/alcionai/corso/src/internal/m365/graph"
@@ -37,11 +38,30 @@ func (r *contactRefresher) refreshContainer(
 
 type contactContainerCache struct {
 	*containerResolver
-	enumer containersEnumerator
+	enumer containersEnumerator[models.ContactFolderable]
 	getter containerGetter
 	userID string
 }
 
+func (cfc *contactContainerCache) init(
+	ctx context.Context,
+	baseNode string,
+	baseContainerPath []string,
+) error {
+	if len(baseNode) == 0 {
+		return clues.New("m365 folderID required for base contact folder").WithClues(ctx)
+	}
+
+	if cfc.containerResolver == nil {
+		cfc.containerResolver = newContainerResolver(&contactRefresher{
+			userID: cfc.userID,
+			getter: cfc.getter,
+		})
+	}
+
+	return cfc.populateContactRoot(ctx, baseNode, baseContainerPath)
+}
+
 func (cfc *contactContainerCache) populateContactRoot(
 	ctx context.Context,
 	directoryID string,
@@ -77,39 +97,35 @@ func (cfc *contactContainerCache) Populate(
 		return clues.Wrap(err, "initializing")
 	}
 
-	err := cfc.enumer.EnumerateContainers(
+	el := errs.Local()
+
+	containers, err := cfc.enumer.EnumerateContainers(
 		ctx,
 		cfc.userID,
 		baseID,
-		false,
-		cfc.addFolder,
-		errs)
+		false)
 	if err != nil {
 		return clues.Wrap(err, "enumerating containers")
 	}
 
+	for _, c := range containers {
+		if el.Failure() != nil {
+			return el.Failure()
+		}
+
+		cacheFolder := graph.NewCacheFolder(c, nil, nil)
+
+		err := cfc.addFolder(&cacheFolder)
+		if err != nil {
+			errs.AddRecoverable(
+				ctx,
+				graph.Stack(ctx, err).Label(fault.LabelForceNoBackupCreation))
+		}
+	}
+
 	if err := cfc.populatePaths(ctx, errs); err != nil {
 		return clues.Wrap(err, "populating paths")
 	}
 
-	return nil
-}
-
-func (cfc *contactContainerCache) init(
-	ctx context.Context,
-	baseNode string,
-	baseContainerPath []string,
-) error {
-	if len(baseNode) == 0 {
-		return clues.New("m365 folderID required for base contact folder").WithClues(ctx)
-	}
-
-	if cfc.containerResolver == nil {
-		cfc.containerResolver = newContainerResolver(&contactRefresher{
-			userID: cfc.userID,
-			getter: cfc.getter,
-		})
-	}
-
-	return cfc.populateContactRoot(ctx, baseNode, baseContainerPath)
+	return el.Failure()
 }

src/internal/m365/collection/exchange/container_resolver.go

@@ -23,14 +23,12 @@ type containerGetter interface {
 	) (graph.Container, error)
 }
 
-type containersEnumerator interface {
+type containersEnumerator[T any] interface {
 	EnumerateContainers(
 		ctx context.Context,
 		userID, baseDirID string,
 		immutableIDs bool,
-		fn func(graph.CachedContainer) error,
-		errs *fault.Bus,
-	) error
+	) ([]T, error)
 }
 
 type containerRefresher interface {

src/internal/m365/collection/exchange/events_container_cache.go

@@ -4,6 +4,7 @@ import (
 	"context"
 
 	"github.com/alcionai/clues"
+	"github.com/microsoftgraph/msgraph-sdk-go/models"
 
 	"github.com/alcionai/corso/src/internal/common/ptr"
 	"github.com/alcionai/corso/src/internal/m365/graph"
@@ -16,7 +17,7 @@ var _ graph.ContainerResolver = &eventContainerCache{}
 
 type eventContainerCache struct {
 	*containerResolver
-	enumer containersEnumerator
+	enumer containersEnumerator[models.Calendarable]
 	getter containerGetter
 	userID string
 }
@@ -70,22 +71,40 @@ func (ecc *eventContainerCache) Populate(
 		return clues.Wrap(err, "initializing")
 	}
 
-	err := ecc.enumer.EnumerateContainers(
+	el := errs.Local()
+
+	containers, err := ecc.enumer.EnumerateContainers(
 		ctx,
 		ecc.userID,
 		"",
-		false,
-		ecc.addFolder,
-		errs)
+		false)
 	if err != nil {
 		return clues.Wrap(err, "enumerating containers")
 	}
 
-	if err := ecc.populatePaths(ctx, errs); err != nil {
-		return clues.Wrap(err, "establishing calendar paths")
+	for _, c := range containers {
+		if el.Failure() != nil {
+			return el.Failure()
+		}
+
+		cacheFolder := graph.NewCacheFolder(
+			api.CalendarDisplayable{Calendarable: c},
+			path.Builder{}.Append(ptr.Val(c.GetId())),
+			path.Builder{}.Append(ptr.Val(c.GetName())))
+
+		err := ecc.addFolder(&cacheFolder)
+		if err != nil {
+			errs.AddRecoverable(
+				ctx,
+				graph.Stack(ctx, err).Label(fault.LabelForceNoBackupCreation))
+		}
 	}
 
-	return nil
+	if err := ecc.populatePaths(ctx, errs); err != nil {
+		return clues.Wrap(err, "populating paths")
+	}
+
+	return el.Failure()
 }
 
 // AddToCache adds container to map in field 'cache'

src/internal/m365/collection/exchange/mail_container_cache.go

@@ -4,6 +4,7 @@ import (
 	"context"
 
 	"github.com/alcionai/clues"
+	"github.com/microsoftgraph/msgraph-sdk-go/models"
 
 	"github.com/alcionai/corso/src/internal/m365/graph"
 	"github.com/alcionai/corso/src/pkg/fault"
@@ -40,7 +41,7 @@ func (r *mailRefresher) refreshContainer(
 // nameLookup map: Key: DisplayName Value: ID
 type mailContainerCache struct {
 	*containerResolver
-	enumer containersEnumerator
+	enumer containersEnumerator[models.MailFolderable]
 	getter containerGetter
 	userID string
 }
@@ -100,20 +101,35 @@ func (mc *mailContainerCache) Populate(
 		return clues.Wrap(err, "initializing")
 	}
 
-	err := mc.enumer.EnumerateContainers(
+	el := errs.Local()
+
+	containers, err := mc.enumer.EnumerateContainers(
 		ctx,
 		mc.userID,
 		"",
-		false,
-		mc.addFolder,
-		errs)
+		false)
 	if err != nil {
 		return clues.Wrap(err, "enumerating containers")
 	}
 
+	for _, c := range containers {
+		if el.Failure() != nil {
+			return el.Failure()
+		}
+
+		cacheFolder := graph.NewCacheFolder(c, nil, nil)
+
+		err := mc.addFolder(&cacheFolder)
+		if err != nil {
+			errs.AddRecoverable(
+				ctx,
+				graph.Stack(ctx, err).Label(fault.LabelForceNoBackupCreation))
+		}
+	}
+
 	if err := mc.populatePaths(ctx, errs); err != nil {
 		return clues.Wrap(err, "populating paths")
 	}
 
-	return nil
+	return el.Failure()
 }

src/pkg/services/m365/api/contacts_pager.go

@@ -10,7 +10,6 @@ import (
 
 	"github.com/alcionai/corso/src/internal/common/ptr"
 	"github.com/alcionai/corso/src/internal/m365/graph"
-	"github.com/alcionai/corso/src/pkg/fault"
 	"github.com/alcionai/corso/src/pkg/path"
 )
 
@@ -67,42 +66,14 @@ func (p *contactsFoldersPageCtrl) ValidModTimes() bool {
 	return true
 }
 
-// EnumerateContainers iterates through all of the users current
-// contacts folders, transforming each to a graph.CacheFolder, and calling
-// fn(cf).
-// Contact folders are represented in their current state, and do
-// not contain historical data.
+// EnumerateContainers retrieves all of the user's current contact folders.
 func (c Contacts) EnumerateContainers(
 	ctx context.Context,
 	userID, baseContainerID string,
 	immutableIDs bool,
-	fn func(graph.CachedContainer) error,
-	errs *fault.Bus,
-) error {
-	var (
-		el  = errs.Local()
-		pgr = c.NewContactFoldersPager(userID, baseContainerID, immutableIDs)
-	)
-
-	containers, err := batchEnumerateItems(ctx, pgr)
-	if err != nil {
-		return graph.Stack(ctx, err)
-	}
-
-	for _, c := range containers {
-		if el.Failure() != nil {
-			break
-		}
-
-		gncf := graph.NewCacheFolder(c, nil, nil)
-
-		if err := fn(&gncf); err != nil {
-			errs.AddRecoverable(ctx, graph.Stack(ctx, err).Label(fault.LabelForceNoBackupCreation))
-			continue
-		}
-	}
-
-	return el.Failure()
+) ([]models.ContactFolderable, error) {
+	containers, err := batchEnumerateItems(ctx, c.NewContactFoldersPager(userID, baseContainerID, immutableIDs))
+	return containers, graph.Stack(ctx, err).OrNil()
 }
 
 // ---------------------------------------------------------------------------

src/pkg/services/m365/api/events_pager.go

@@ -11,7 +11,6 @@ import (
 
 	"github.com/alcionai/corso/src/internal/common/ptr"
 	"github.com/alcionai/corso/src/internal/m365/graph"
-	"github.com/alcionai/corso/src/pkg/fault"
 	"github.com/alcionai/corso/src/pkg/path"
 )
 
@@ -68,45 +67,14 @@ func (p *eventsCalendarsPageCtrl) ValidModTimes() bool {
 	return true
 }
 
-// EnumerateContainers iterates through all of the users current
-// events calendars, transforming each to a graph.CacheFolder, and calling
-// fn(cf).
-// Calendars are represented in their current state, and do
-// not contain historical data.
+// EnumerateContainers retrieves all of the user's current mail folders.
 func (c Events) EnumerateContainers(
 	ctx context.Context,
-	userID, _ string, // baseContainerID not needed
+	userID, _ string, // baseContainerID not needed here
 	immutableIDs bool,
-	fn func(graph.CachedContainer) error,
-	errs *fault.Bus,
-) error {
-	var (
-		el  = errs.Local()
-		pgr = c.NewEventCalendarsPager(userID, immutableIDs)
-	)
-
-	containers, err := batchEnumerateItems(ctx, pgr)
-	if err != nil {
-		return graph.Stack(ctx, err)
-	}
-
-	for _, c := range containers {
-		if el.Failure() != nil {
-			break
-		}
-
-		gncf := graph.NewCacheFolder(
-			CalendarDisplayable{Calendarable: c},
-			path.Builder{}.Append(ptr.Val(c.GetId())),
-			path.Builder{}.Append(ptr.Val(c.GetName())))
-
-		if err := fn(&gncf); err != nil {
-			errs.AddRecoverable(ctx, graph.Stack(ctx, err).Label(fault.LabelForceNoBackupCreation))
-			continue
-		}
-	}
-
-	return el.Failure()
+) ([]models.Calendarable, error) {
+	containers, err := batchEnumerateItems(ctx, c.NewEventCalendarsPager(userID, immutableIDs))
+	return containers, graph.Stack(ctx, err).OrNil()
 }
 
 // ---------------------------------------------------------------------------

src/pkg/services/m365/api/events_test.go

@@ -13,13 +13,11 @@ import (
 
 	"github.com/alcionai/corso/src/internal/common/dttm"
 	"github.com/alcionai/corso/src/internal/common/ptr"
-	"github.com/alcionai/corso/src/internal/m365/graph"
 	exchMock "github.com/alcionai/corso/src/internal/m365/service/exchange/mock"
 	"github.com/alcionai/corso/src/internal/tester"
 	"github.com/alcionai/corso/src/internal/tester/tconfig"
 	"github.com/alcionai/corso/src/pkg/backup/details"
 	"github.com/alcionai/corso/src/pkg/control/testdata"
-	"github.com/alcionai/corso/src/pkg/fault"
 	"github.com/alcionai/corso/src/pkg/services/m365/api"
 )
 
@@ -294,8 +292,8 @@ func (suite *EventsAPIIntgSuite) TestEvents_canFindNonStandardFolder() {
 	var (
 		found         bool
 		calID         = ptr.Val(cal.GetId())
-		findContainer = func(gcc graph.CachedContainer) error {
-			if ptr.Val(gcc.GetId()) == calID {
+		findContainer = func(mc models.Calendarable) error {
+			if ptr.Val(mc.GetId()) == calID {
 				found = true
 			}
 
@@ -303,14 +301,18 @@ func (suite *EventsAPIIntgSuite) TestEvents_canFindNonStandardFolder() {
 		}
 	)
 
-	err = ac.EnumerateContainers(
+	containers, err := ac.EnumerateContainers(
 		ctx,
 		suite.its.user.id,
 		api.DefaultCalendar,
-		false,
-		findContainer,
-		fault.New(true))
+		false)
 	require.NoError(t, err, clues.ToCore(err))
+
+	for _, c := range containers {
+		err := findContainer(c)
+		require.NoError(t, err, clues.ToCore(err))
+	}
+
 	require.True(
 		t,
 		found,

src/pkg/services/m365/api/mail_pager.go

@@ -11,7 +11,6 @@ import (
 
 	"github.com/alcionai/corso/src/internal/common/ptr"
 	"github.com/alcionai/corso/src/internal/m365/graph"
-	"github.com/alcionai/corso/src/pkg/fault"
 	"github.com/alcionai/corso/src/pkg/path"
 )
 
@@ -64,42 +63,14 @@ func (p *mailFoldersPageCtrl) ValidModTimes() bool {
 	return true
 }
 
-// EnumerateContainers iterates through all of the users current
-// mail folders, transforming each to a graph.CacheFolder, and calling
-// fn(cf).
-// Folder hierarchy is represented in its current state, and does
-// not contain historical data.
+// EnumerateContainers retrieves all of the user's current mail folders.
 func (c Mail) EnumerateContainers(
 	ctx context.Context,
 	userID, _ string, // baseContainerID not needed here
 	immutableIDs bool,
-	fn func(graph.CachedContainer) error,
-	errs *fault.Bus,
-) error {
-	var (
-		el  = errs.Local()
-		pgr = c.NewMailFoldersPager(userID, immutableIDs)
-	)
-
-	containers, err := batchEnumerateItems(ctx, pgr)
-	if err != nil {
-		return graph.Stack(ctx, err)
-	}
-
-	for _, c := range containers {
-		if el.Failure() != nil {
-			break
-		}
-
-		gncf := graph.NewCacheFolder(c, nil, nil)
-
-		if err := fn(&gncf); err != nil {
-			errs.AddRecoverable(ctx, graph.Stack(ctx, err).Label(fault.LabelForceNoBackupCreation))
-			continue
-		}
-	}
-
-	return el.Failure()
+) ([]models.MailFolderable, error) {
+	containers, err := batchEnumerateItems(ctx, c.NewMailFoldersPager(userID, immutableIDs))
+	return containers, graph.Stack(ctx, err).OrNil()
 }
 
 // ---------------------------------------------------------------------------