Add tests to check for invalid email addresses in eml export (#4881)

<!-- PR description-->

---

#### 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
- [ ] 🐛 Bugfix
- [ ] 🗺️ Documentation
- [x] 🤖 Supportability/Tests
- [ ] 💻 CI/Deployment
- [ ] 🧹 Tech Debt/Cleanup

#### Issue(s)

<!-- Can reference multiple issues. Use one of the following "magic words" - "closes, fixes" to auto-close the Github issue. -->
* #<issue>

#### Test Plan

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

src/internal/converters/eml/eml_test.go

@@ -131,7 +131,36 @@ func (suite *EMLUnitSuite) TestConvert_messageble_to_eml() {
 	assert.Equal(t, source, target)
 }
 
-func (suite *EMLUnitSuite) TestConvert_empty_attachment_no_err() {
+func (suite *EMLUnitSuite) TestConvert_edge_cases() {
+	tests := []struct {
+		name      string
+		transform func(models.Messageable)
+	}{
+		{
+			name: "just a name",
+			transform: func(msg models.Messageable) {
+				msg.GetFrom().GetEmailAddress().SetName(ptr.To("alphabob"))
+				msg.GetFrom().GetEmailAddress().SetAddress(nil)
+			},
+		},
+		{
+			name: "incorrect address",
+			transform: func(msg models.Messageable) {
+				msg.GetFrom().GetEmailAddress().SetAddress(ptr.To("invalid"))
+			},
+		},
+		{
+			name: "empty attachment",
+			transform: func(msg models.Messageable) {
+				attachments := msg.GetAttachments()
+				err := attachments[0].GetBackingStore().Set("contentBytes", []uint8{})
+				require.NoError(suite.T(), err, "setting attachment content")
+			},
+		},
+	}
+
+	for _, test := range tests {
+		suite.Run(test.name, func() {
 			t := suite.T()
 
 			ctx, flush := tester.NewContext(t)
@@ -142,9 +171,7 @@ func (suite *EMLUnitSuite) TestConvert_empty_attachment_no_err() {
 			msg, err := api.BytesToMessageable(body)
 			require.NoError(t, err, "creating message")
 
-	attachments := msg.GetAttachments()
+			test.transform(msg)
-	err = attachments[0].GetBackingStore().Set("contentBytes", []uint8{})
-	require.NoError(t, err, "setting content bytes")
 
 			writer := kjson.NewJsonSerializationWriter()
 
@@ -158,4 +185,6 @@ func (suite *EMLUnitSuite) TestConvert_empty_attachment_no_err() {
 
 			_, err = FromJSON(ctx, nbody)
 			assert.NoError(t, err, "converting to eml")
+		})
+	}
 }

src/internal/data/metrics.go

@@ -1,12 +1,5 @@
 package data
 
-import (
-	"io"
-	"sync/atomic"
-
-	"github.com/alcionai/corso/src/pkg/path"
-)
-
 type CollectionStats struct {
 	Folders,
 	Objects,
@@ -22,68 +15,3 @@ func (cs CollectionStats) IsZero() bool {
 func (cs CollectionStats) String() string {
 	return cs.Details
 }
-
-type KindStats struct {
-	BytesRead     int64
-	ResourceCount int64
-}
-
-type ExportStats struct {
-	// data is kept private so that we can enforce atomic int updates
-	data map[path.CategoryType]KindStats
-}
-
-func (es *ExportStats) UpdateBytes(kind path.CategoryType, bytesRead int64) {
-	if es.data == nil {
-		es.data = map[path.CategoryType]KindStats{}
-	}
-
-	ks := es.data[kind]
-	atomic.AddInt64(&ks.BytesRead, bytesRead)
-	es.data[kind] = ks
-}
-
-func (es *ExportStats) UpdateResourceCount(kind path.CategoryType) {
-	if es.data == nil {
-		es.data = map[path.CategoryType]KindStats{}
-	}
-
-	ks := es.data[kind]
-	atomic.AddInt64(&ks.ResourceCount, 1)
-	es.data[kind] = ks
-}
-
-func (es *ExportStats) GetStats() map[path.CategoryType]KindStats {
-	return es.data
-}
-
-type statsReader struct {
-	io.ReadCloser
-	kind  path.CategoryType
-	stats *ExportStats
-}
-
-func (sr *statsReader) Read(p []byte) (int, error) {
-	n, err := sr.ReadCloser.Read(p)
-	sr.stats.UpdateBytes(sr.kind, int64(n))
-
-	return n, err
-}
-
-// Create a function that will take a reader and return a reader that
-// will update the stats
-func ReaderWithStats(
-	reader io.ReadCloser,
-	kind path.CategoryType,
-	stats *ExportStats,
-) io.ReadCloser {
-	if reader == nil {
-		return nil
-	}
-
-	return &statsReader{
-		ReadCloser: reader,
-		kind:       kind,
-		stats:      stats,
-	}
-}

src/internal/m365/collection/drive/export.go

@@ -12,6 +12,7 @@ import (
 	"github.com/alcionai/corso/src/pkg/control"
 	"github.com/alcionai/corso/src/pkg/export"
 	"github.com/alcionai/corso/src/pkg/fault"
+	"github.com/alcionai/corso/src/pkg/metrics"
 	"github.com/alcionai/corso/src/pkg/path"
 )
 
@@ -19,7 +20,7 @@ func NewExportCollection(
 	baseDir string,
 	backingCollection []data.RestoreCollection,
 	backupVersion int,
-	stats *data.ExportStats,
+	stats *metrics.ExportStats,
 ) export.Collectioner {
 	return export.BaseCollection{
 		BaseDir:           baseDir,
@@ -37,7 +38,7 @@ func streamItems(
 	backupVersion int,
 	cec control.ExportConfig,
 	ch chan<- export.Item,
-	stats *data.ExportStats,
+	stats *metrics.ExportStats,
 ) {
 	defer close(ch)
 
@@ -61,7 +62,7 @@ func streamItems(
 			}
 
 			stats.UpdateResourceCount(path.FilesCategory)
-			body := data.ReaderWithStats(item.ToReader(), path.FilesCategory, stats)
+			body := metrics.ReaderWithStats(item.ToReader(), path.FilesCategory, stats)
 
 			ch <- export.Item{
 				ID:    itemUUID,

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

@@ -12,6 +12,7 @@ import (
 	"github.com/alcionai/corso/src/pkg/control"
 	"github.com/alcionai/corso/src/pkg/export"
 	"github.com/alcionai/corso/src/pkg/fault"
+	"github.com/alcionai/corso/src/pkg/metrics"
 	"github.com/alcionai/corso/src/pkg/path"
 )
 
@@ -19,7 +20,7 @@ func NewExportCollection(
 	baseDir string,
 	backingCollection []data.RestoreCollection,
 	backupVersion int,
-	stats *data.ExportStats,
+	stats *metrics.ExportStats,
 ) export.Collectioner {
 	return export.BaseCollection{
 		BaseDir:           baseDir,
@@ -37,7 +38,7 @@ func streamItems(
 	backupVersion int,
 	config control.ExportConfig,
 	ch chan<- export.Item,
-	stats *data.ExportStats,
+	stats *metrics.ExportStats,
 ) {
 	defer close(ch)
 
@@ -77,7 +78,7 @@ func streamItems(
 			}
 
 			emlReader := io.NopCloser(bytes.NewReader([]byte(email)))
-			body := data.ReaderWithStats(emlReader, path.EmailCategory, stats)
+			body := metrics.ReaderWithStats(emlReader, path.EmailCategory, stats)
 
 			ch <- export.Item{
 				ID:   id,

src/internal/m365/collection/groups/export.go

@@ -15,6 +15,7 @@ import (
 	"github.com/alcionai/corso/src/pkg/control"
 	"github.com/alcionai/corso/src/pkg/export"
 	"github.com/alcionai/corso/src/pkg/fault"
+	"github.com/alcionai/corso/src/pkg/metrics"
 	"github.com/alcionai/corso/src/pkg/path"
 	"github.com/alcionai/corso/src/pkg/services/m365/api"
 )
@@ -24,7 +25,7 @@ func NewExportCollection(
 	backingCollections []data.RestoreCollection,
 	backupVersion int,
 	cec control.ExportConfig,
-	stats *data.ExportStats,
+	stats *metrics.ExportStats,
 ) export.Collectioner {
 	return export.BaseCollection{
 		BaseDir:           baseDir,
@@ -43,7 +44,7 @@ func streamItems(
 	backupVersion int,
 	cec control.ExportConfig,
 	ch chan<- export.Item,
-	stats *data.ExportStats,
+	stats *metrics.ExportStats,
 ) {
 	defer close(ch)
 
@@ -59,7 +60,7 @@ func streamItems(
 				}
 			} else {
 				stats.UpdateResourceCount(path.ChannelMessagesCategory)
-				body = data.ReaderWithStats(body, path.ChannelMessagesCategory, stats)
+				body = metrics.ReaderWithStats(body, path.ChannelMessagesCategory, stats)
 
 				// messages are exported as json and should be named as such
 				name := item.ID() + ".json"

src/internal/m365/collection/groups/export_test.go

@@ -15,6 +15,7 @@ import (
 	"github.com/alcionai/corso/src/internal/version"
 	"github.com/alcionai/corso/src/pkg/control"
 	"github.com/alcionai/corso/src/pkg/export"
+	"github.com/alcionai/corso/src/pkg/metrics"
 )
 
 type ExportUnitSuite struct {
@@ -91,7 +92,7 @@ func (suite *ExportUnitSuite) TestStreamItems() {
 				version.NoBackup,
 				control.DefaultExportConfig(),
 				ch,
-				&data.ExportStats{})
+				&metrics.ExportStats{})
 
 			var (
 				itm export.Item

src/internal/m365/mock/connector.go

@@ -15,6 +15,7 @@ import (
 	"github.com/alcionai/corso/src/pkg/count"
 	"github.com/alcionai/corso/src/pkg/export"
 	"github.com/alcionai/corso/src/pkg/fault"
+	"github.com/alcionai/corso/src/pkg/metrics"
 	"github.com/alcionai/corso/src/pkg/path"
 )
 
@@ -87,7 +88,7 @@ func (ctrl Controller) ProduceExportCollections(
 	_ int,
 	_ control.ExportConfig,
 	_ []data.RestoreCollection,
-	_ *data.ExportStats,
+	_ *metrics.ExportStats,
 	_ *fault.Bus,
 ) ([]export.Collectioner, error) {
 	return nil, ctrl.Err

src/internal/m365/service/exchange/export.go

@@ -15,6 +15,7 @@ import (
 	"github.com/alcionai/corso/src/pkg/export"
 	"github.com/alcionai/corso/src/pkg/fault"
 	"github.com/alcionai/corso/src/pkg/logger"
+	"github.com/alcionai/corso/src/pkg/metrics"
 	"github.com/alcionai/corso/src/pkg/path"
 	"github.com/alcionai/corso/src/pkg/services/m365/api"
 )
@@ -54,7 +55,7 @@ func (h *baseExchangeHandler) ProduceExportCollections(
 	backupVersion int,
 	exportCfg control.ExportConfig,
 	dcs []data.RestoreCollection,
-	stats *data.ExportStats,
+	stats *metrics.ExportStats,
 	errs *fault.Bus,
 ) ([]export.Collectioner, error) {
 	var (

src/internal/m365/service/exchange/export_test.go

@@ -18,6 +18,7 @@ import (
 	"github.com/alcionai/corso/src/pkg/control"
 	"github.com/alcionai/corso/src/pkg/export"
 	"github.com/alcionai/corso/src/pkg/fault"
+	"github.com/alcionai/corso/src/pkg/metrics"
 	"github.com/alcionai/corso/src/pkg/path"
 	"github.com/alcionai/corso/src/pkg/services/m365/api"
 )
@@ -144,7 +145,7 @@ func (suite *ExportUnitSuite) TestGetItems() {
 			ctx, flush := tester.NewContext(t)
 			defer flush()
 
-			stats := data.ExportStats{}
+			stats := metrics.ExportStats{}
 			ec := exchange.NewExportCollection(
 				"",
 				[]data.RestoreCollection{test.backingCollection},
@@ -184,10 +185,10 @@ func (suite *ExportUnitSuite) TestGetItems() {
 				assert.ErrorIs(t, item.Error, test.expectedItems[i].Error)
 			}
 
-			var expectedStats data.ExportStats
+			var expectedStats metrics.ExportStats
 
 			if size+count > 0 { // it is only initialized if we have something
-				expectedStats = data.ExportStats{}
+				expectedStats = metrics.ExportStats{}
 				expectedStats.UpdateBytes(path.EmailCategory, int64(size))
 
 				for i := 0; i < count; i++ {
@@ -379,7 +380,7 @@ func (suite *ExportUnitSuite) TestExportRestoreCollections() {
 	for _, tt := range tests {
 		t.Run(tt.name, func(t *testing.T) {
 			exportCfg := control.ExportConfig{}
-			stats := data.ExportStats{}
+			stats := metrics.ExportStats{}
 
 			ecs, err := NewExchangeHandler(control.DefaultOptions(), api.Client{}, nil).
 				ProduceExportCollections(
@@ -398,7 +399,7 @@ func (suite *ExportUnitSuite) TestExportRestoreCollections() {
 			assert.NoError(t, err, "export collections error")
 			assert.Len(t, ecs, len(tt.expectedItems), "num of collections")
 
-			expectedStats := data.ExportStats{}
+			expectedStats := metrics.ExportStats{}
 
 			// We are dependent on the order the collections are
 			// returned in the test which is not necessary for the

src/internal/m365/service/groups/export.go

@@ -17,6 +17,7 @@ import (
 	"github.com/alcionai/corso/src/pkg/export"
 	"github.com/alcionai/corso/src/pkg/fault"
 	"github.com/alcionai/corso/src/pkg/logger"
+	"github.com/alcionai/corso/src/pkg/metrics"
 	"github.com/alcionai/corso/src/pkg/path"
 	"github.com/alcionai/corso/src/pkg/services/m365/api"
 )
@@ -68,7 +69,7 @@ func (h *baseGroupsHandler) ProduceExportCollections(
 	backupVersion int,
 	exportCfg control.ExportConfig,
 	dcs []data.RestoreCollection,
-	stats *data.ExportStats,
+	stats *metrics.ExportStats,
 	errs *fault.Bus,
 ) ([]export.Collectioner, error) {
 	var (

src/internal/m365/service/groups/export_test.go

@@ -20,6 +20,7 @@ import (
 	"github.com/alcionai/corso/src/pkg/control"
 	"github.com/alcionai/corso/src/pkg/export"
 	"github.com/alcionai/corso/src/pkg/fault"
+	"github.com/alcionai/corso/src/pkg/metrics"
 	"github.com/alcionai/corso/src/pkg/path"
 	"github.com/alcionai/corso/src/pkg/services/m365/api"
 )
@@ -95,7 +96,7 @@ func (suite *ExportUnitSuite) TestExportRestoreCollections_messages() {
 		},
 	}
 
-	stats := data.ExportStats{}
+	stats := metrics.ExportStats{}
 
 	ecs, err := NewGroupsHandler(control.DefaultOptions(), api.Client{}, nil).
 		ProduceExportCollections(
@@ -129,7 +130,7 @@ func (suite *ExportUnitSuite) TestExportRestoreCollections_messages() {
 
 	assert.Equal(t, expectedItems, fitems, "items")
 
-	expectedStats := data.ExportStats{}
+	expectedStats := metrics.ExportStats{}
 	expectedStats.UpdateBytes(path.ChannelMessagesCategory, int64(size))
 	expectedStats.UpdateResourceCount(path.ChannelMessagesCategory)
 	assert.Equal(t, expectedStats, stats, "stats")
@@ -200,7 +201,7 @@ func (suite *ExportUnitSuite) TestExportRestoreCollections_libraries() {
 	handler := NewGroupsHandler(control.DefaultOptions(), api.Client{}, nil)
 	handler.CacheItemInfo(dii)
 
-	stats := data.ExportStats{}
+	stats := metrics.ExportStats{}
 
 	ecs, err := handler.ProduceExportCollections(
 		ctx,
@@ -232,7 +233,7 @@ func (suite *ExportUnitSuite) TestExportRestoreCollections_libraries() {
 
 	assert.Equal(t, expectedItems, fitems, "items")
 
-	expectedStats := data.ExportStats{}
+	expectedStats := metrics.ExportStats{}
 	expectedStats.UpdateBytes(path.FilesCategory, int64(size))
 	expectedStats.UpdateResourceCount(path.FilesCategory)
 	assert.Equal(t, expectedStats, stats, "stats")

src/internal/m365/service/onedrive/export.go

@@ -14,6 +14,7 @@ import (
 	"github.com/alcionai/corso/src/pkg/control"
 	"github.com/alcionai/corso/src/pkg/export"
 	"github.com/alcionai/corso/src/pkg/fault"
+	"github.com/alcionai/corso/src/pkg/metrics"
 	"github.com/alcionai/corso/src/pkg/path"
 	"github.com/alcionai/corso/src/pkg/services/m365/api"
 )
@@ -61,7 +62,7 @@ func (h *baseOneDriveHandler) ProduceExportCollections(
 	backupVersion int,
 	exportCfg control.ExportConfig,
 	dcs []data.RestoreCollection,
-	stats *data.ExportStats,
+	stats *metrics.ExportStats,
 	errs *fault.Bus,
 ) ([]export.Collectioner, error) {
 	var (

src/internal/m365/service/onedrive/export_test.go

@@ -19,6 +19,7 @@ import (
 	"github.com/alcionai/corso/src/pkg/control"
 	"github.com/alcionai/corso/src/pkg/export"
 	"github.com/alcionai/corso/src/pkg/fault"
+	"github.com/alcionai/corso/src/pkg/metrics"
 	"github.com/alcionai/corso/src/pkg/path"
 	"github.com/alcionai/corso/src/pkg/services/m365/api"
 )
@@ -247,7 +248,7 @@ func (suite *ExportUnitSuite) TestGetItems() {
 			ctx, flush := tester.NewContext(t)
 			defer flush()
 
-			stats := data.ExportStats{}
+			stats := metrics.ExportStats{}
 			ec := drive.NewExportCollection(
 				"",
 				[]data.RestoreCollection{test.backingCollection},
@@ -288,10 +289,10 @@ func (suite *ExportUnitSuite) TestGetItems() {
 				assert.ErrorIs(t, item.Error, test.expectedItems[i].Error)
 			}
 
-			var expectedStats data.ExportStats
+			var expectedStats metrics.ExportStats
 
 			if size+count > 0 { // it is only initialized if we have something
-				expectedStats = data.ExportStats{}
+				expectedStats = metrics.ExportStats{}
 				expectedStats.UpdateBytes(path.FilesCategory, int64(size))
 
 				for i := 0; i < count; i++ {
@@ -340,7 +341,7 @@ func (suite *ExportUnitSuite) TestExportRestoreCollections() {
 		},
 	}
 
-	stats := data.ExportStats{}
+	stats := metrics.ExportStats{}
 
 	ecs, err := NewOneDriveHandler(control.DefaultOptions(), api.Client{}, nil).
 		ProduceExportCollections(
@@ -370,7 +371,7 @@ func (suite *ExportUnitSuite) TestExportRestoreCollections() {
 
 	assert.Equal(t, expectedItems, fitems, "items")
 
-	expectedStats := data.ExportStats{}
+	expectedStats := metrics.ExportStats{}
 	expectedStats.UpdateBytes(path.FilesCategory, int64(size))
 	expectedStats.UpdateResourceCount(path.FilesCategory)
 	assert.Equal(t, expectedStats, stats, "stats")

src/internal/m365/service/sharepoint/export.go

@@ -15,6 +15,7 @@ import (
 	"github.com/alcionai/corso/src/pkg/export"
 	"github.com/alcionai/corso/src/pkg/fault"
 	"github.com/alcionai/corso/src/pkg/logger"
+	"github.com/alcionai/corso/src/pkg/metrics"
 	"github.com/alcionai/corso/src/pkg/path"
 	"github.com/alcionai/corso/src/pkg/services/m365/api"
 )
@@ -65,7 +66,7 @@ func (h *baseSharePointHandler) ProduceExportCollections(
 	backupVersion int,
 	exportCfg control.ExportConfig,
 	dcs []data.RestoreCollection,
-	stats *data.ExportStats,
+	stats *metrics.ExportStats,
 	errs *fault.Bus,
 ) ([]export.Collectioner, error) {
 	var (

src/internal/m365/service/sharepoint/export_test.go

@@ -19,6 +19,7 @@ import (
 	"github.com/alcionai/corso/src/pkg/control"
 	"github.com/alcionai/corso/src/pkg/export"
 	"github.com/alcionai/corso/src/pkg/fault"
+	"github.com/alcionai/corso/src/pkg/metrics"
 	"github.com/alcionai/corso/src/pkg/path"
 	"github.com/alcionai/corso/src/pkg/services/m365/api"
 )
@@ -129,7 +130,7 @@ func (suite *ExportUnitSuite) TestExportRestoreCollections() {
 			handler := NewSharePointHandler(control.DefaultOptions(), api.Client{}, nil)
 			handler.CacheItemInfo(test.itemInfo)
 
-			stats := data.ExportStats{}
+			stats := metrics.ExportStats{}
 
 			ecs, err := handler.ProduceExportCollections(
 				ctx,
@@ -160,7 +161,7 @@ func (suite *ExportUnitSuite) TestExportRestoreCollections() {
 
 			assert.Equal(t, expectedItems, fitems, "items")
 
-			expectedStats := data.ExportStats{}
+			expectedStats := metrics.ExportStats{}
 			expectedStats.UpdateBytes(path.FilesCategory, int64(size))
 			expectedStats.UpdateResourceCount(path.FilesCategory)
 			assert.Equal(t, expectedStats, stats, "stats")

src/internal/operations/export.go

@@ -27,6 +27,7 @@ import (
 	"github.com/alcionai/corso/src/pkg/export"
 	"github.com/alcionai/corso/src/pkg/fault"
 	"github.com/alcionai/corso/src/pkg/logger"
+	"github.com/alcionai/corso/src/pkg/metrics"
 	"github.com/alcionai/corso/src/pkg/path"
 	"github.com/alcionai/corso/src/pkg/selectors"
 	"github.com/alcionai/corso/src/pkg/store"
@@ -47,7 +48,7 @@ type ExportOperation struct {
 	Selectors selectors.Selector
 	ExportCfg control.ExportConfig
 	Version   string
-	stats     data.ExportStats
+	stats     metrics.ExportStats
 
 	acct account.Account
 	ec   inject.ExportConsumer
@@ -74,7 +75,7 @@ func NewExportOperation(
 		Selectors: sel,
 		Version:   "v0",
 		ec:        ec,
-		stats:     data.ExportStats{},
+		stats:     metrics.ExportStats{},
 	}
 	if err := op.validate(); err != nil {
 		return ExportOperation{}, err
@@ -322,7 +323,7 @@ func (op *ExportOperation) finalizeMetrics(
 // be calling this once the export collections have been read and process
 // as the data that will be available here will be the data that was read
 // and processed.
-func (op *ExportOperation) GetStats() map[path.CategoryType]data.KindStats {
+func (op *ExportOperation) GetStats() map[path.CategoryType]metrics.KindStats {
 	return op.stats.GetStats()
 }
 
@@ -336,7 +337,7 @@ func produceExportCollections(
 	backupVersion int,
 	exportCfg control.ExportConfig,
 	dcs []data.RestoreCollection,
-	exportStats *data.ExportStats,
+	exportStats *metrics.ExportStats,
 	errs *fault.Bus,
 ) ([]export.Collectioner, error) {
 	complete := observe.MessageWithCompletion(ctx, observe.ProgressCfg{}, "Preparing export")

src/internal/operations/inject/inject.go

@@ -16,6 +16,7 @@ import (
 	"github.com/alcionai/corso/src/pkg/count"
 	"github.com/alcionai/corso/src/pkg/export"
 	"github.com/alcionai/corso/src/pkg/fault"
+	"github.com/alcionai/corso/src/pkg/metrics"
 	"github.com/alcionai/corso/src/pkg/path"
 )
 
@@ -96,7 +97,7 @@ type (
 			backupVersion int,
 			exportCfg control.ExportConfig,
 			dcs []data.RestoreCollection,
-			stats *data.ExportStats,
+			stats *metrics.ExportStats,
 			errs *fault.Bus,
 		) ([]export.Collectioner, error)
 

src/pkg/export/export.go

@@ -6,6 +6,7 @@ import (
 
 	"github.com/alcionai/corso/src/internal/data"
 	"github.com/alcionai/corso/src/pkg/control"
+	"github.com/alcionai/corso/src/pkg/metrics"
 )
 
 // ---------------------------------------------------------------------------
@@ -29,7 +30,7 @@ type itemStreamer func(
 	backupVersion int,
 	cfg control.ExportConfig,
 	ch chan<- Item,
-	stats *data.ExportStats)
+	stats *metrics.ExportStats)
 
 // BaseCollection holds the foundational details of an export collection.
 type BaseCollection struct {
@@ -47,7 +48,7 @@ type BaseCollection struct {
 
 	Stream itemStreamer
 
-	Stats *data.ExportStats
+	Stats *metrics.ExportStats
 }
 
 func (bc BaseCollection) BasePath() string {

src/pkg/metrics/metrics.go

@@ -0,0 +1,73 @@
+package metrics
+
+import (
+	"io"
+	"sync/atomic"
+
+	"github.com/alcionai/corso/src/pkg/path"
+)
+
+type KindStats struct {
+	BytesRead     int64
+	ResourceCount int64
+}
+
+type ExportStats struct {
+	// data is kept private so that we can enforce atomic int updates
+	data map[path.CategoryType]KindStats
+}
+
+func (es *ExportStats) UpdateBytes(kind path.CategoryType, bytesRead int64) {
+	if es.data == nil {
+		es.data = map[path.CategoryType]KindStats{}
+	}
+
+	ks := es.data[kind]
+	atomic.AddInt64(&ks.BytesRead, bytesRead)
+	es.data[kind] = ks
+}
+
+func (es *ExportStats) UpdateResourceCount(kind path.CategoryType) {
+	if es.data == nil {
+		es.data = map[path.CategoryType]KindStats{}
+	}
+
+	ks := es.data[kind]
+	atomic.AddInt64(&ks.ResourceCount, 1)
+	es.data[kind] = ks
+}
+
+func (es *ExportStats) GetStats() map[path.CategoryType]KindStats {
+	return es.data
+}
+
+type statsReader struct {
+	io.ReadCloser
+	kind  path.CategoryType
+	stats *ExportStats
+}
+
+func (sr *statsReader) Read(p []byte) (int, error) {
+	n, err := sr.ReadCloser.Read(p)
+	sr.stats.UpdateBytes(sr.kind, int64(n))
+
+	return n, err
+}
+
+// Create a function that will take a reader and return a reader that
+// will update the stats
+func ReaderWithStats(
+	reader io.ReadCloser,
+	kind path.CategoryType,
+	stats *ExportStats,
+) io.ReadCloser {
+	if reader == nil {
+		return nil
+	}
+
+	return &statsReader{
+		ReadCloser: reader,
+		kind:       kind,
+		stats:      stats,
+	}
+}