Exchange.Collection.Items() to initiate populate method (#446)

`Items()` starts populate method for collection for the `exchange.Collection` package. Test packages expanded to verify the functionality of this feature.

src/internal/connector/exchange/exchange_data_collection.go

@@ -41,17 +41,26 @@ type Collection struct {
 	// is desired to be sent through the data channel for eventual storage
 	jobs []string
 
+	service  graph.Service
+	statusCh chan<- *support.ConnectorOperationStatus
 	// FullPath is the slice representation of the action context passed down through the hierarchy.
 	//The original request can be gleaned from the slice. (e.g. {<tenant ID>, <user ID>, "emails"})
 	fullPath []string
 }
 
 // NewExchangeDataCollection creates an ExchangeDataCollection with fullPath is annotated
-func NewCollection(aUser string, pathRepresentation []string) Collection {
+func NewCollection(
+	aUser string,
+	pathRepresentation []string,
+	aService graph.Service,
+	statusCh chan<- *support.ConnectorOperationStatus,
+) Collection {
 	collection := Collection{
 		user:     aUser,
 		data:     make(chan data.Stream, collectionChannelBufferSize),
 		jobs:     make([]string, 0),
+		service:  aService,
+		statusCh: statusCh,
 		fullPath: pathRepresentation,
 	}
 	return collection
@@ -62,9 +71,15 @@ func (eoc *Collection) AddJob(objID string) {
 	eoc.jobs = append(eoc.jobs, objID)
 }
 
-// PopulateCollection TODO: remove after async functionilty completed
-func (eoc *Collection) PopulateCollection(newData *Stream) {
-	eoc.data <- newData
+// Items utility function to asynchronously execute process to fill data channel with
+// M365 exchange objects and returns the data channel
+func (eoc *Collection) Items() <-chan data.Stream {
+	go eoc.PopulateFromCollection(context.TODO(), eoc.service, eoc.statusCh)
+	return eoc.data
+}
+
+func (edc *Collection) FullPath() []string {
+	return append([]string{}, edc.fullPath...)
 }
 
 // populateFromTaskList async call to fill DataCollection via channel implementation
@@ -155,14 +170,6 @@ func messageToDataCollection(
 	return nil
 }
 
-func (eoc *Collection) Items() <-chan data.Stream {
-	return eoc.data
-}
-
-func (edc *Collection) FullPath() []string {
-	return append([]string{}, edc.fullPath...)
-}
-
 // Stream represents a single item retrieved from exchange
 type Stream struct {
 	id string
@@ -185,6 +192,8 @@ func (od *Stream) ToReader() io.ReadCloser {
 func (od *Stream) Info() details.ItemInfo {
 	return details.ItemInfo{Exchange: od.info}
 }
+
+// NewStream constructor for exchange.Stream object
 func NewStream(identifier string, bytes []byte, detail details.ExchangeInfo) Stream {
 	return Stream{
 		id:      identifier,

src/internal/connector/exchange/exchange_data_collection_test.go

@@ -50,52 +50,30 @@ func (suite *ExchangeDataCollectionSuite) TestExchangeDataReader_Empty() {
 func (suite *ExchangeDataCollectionSuite) TestExchangeData_FullPath() {
 	user := "a-user"
 	fullPath := []string{"a-tenant", user, "emails"}
-	edc := NewCollection(user, fullPath)
+	edc := Collection{
+		user:     user,
+		fullPath: fullPath,
+	}
 	assert.Equal(suite.T(), edc.FullPath(), fullPath)
 }
 
 func (suite *ExchangeDataCollectionSuite) TestExchangeDataCollection_NewExchangeDataCollection() {
 	name := "User"
-	edc := NewCollection(name, []string{"Directory", "File", "task"})
+	edc := Collection{
+		user:     name,
+		fullPath: []string{"Directory", "File", "task"},
+	}
 	suite.Equal(name, edc.user)
 	suite.True(contains(edc.FullPath(), "Directory"))
 	suite.True(contains(edc.FullPath(), "File"))
 	suite.True(contains(edc.FullPath(), "task"))
 }
 
-func (suite *ExchangeDataCollectionSuite) TestExchangeDataCollection_PopulateCollection() {
-	inputStrings := []string{"Jack", "and", "Jill", "went", "up", "the", "hill to",
-		"fetch", "a", "pail", "of", "water"}
-	expected := len(inputStrings) / 2 // We are using pairs
-	edc := NewCollection("Fletcher", []string{"sugar", "horses", "painted red"})
-	for i := 0; i < expected; i++ {
-		edc.PopulateCollection(&Stream{id: inputStrings[i*2], message: []byte(inputStrings[i*2+1])})
-	}
-	suite.Equal(expected, len(edc.data))
-}
-
-func (suite *ExchangeDataCollectionSuite) TestExchangeDataCollection_Items() {
-	inputStrings := []string{"Jack", "and", "Jill", "went", "up", "the", "hill to",
-		"fetch", "a", "pail", "of", "water"}
-	expected := len(inputStrings) / 2 // We are using pairs
-	edc := NewCollection("Fletcher", []string{"sugar", "horses", "painted red"})
-	for i := 0; i < expected; i++ {
-		edc.data <- &Stream{id: inputStrings[i*2], message: []byte(inputStrings[i*2+1])}
-	}
-	close(edc.data)
-	suite.Equal(expected, len(edc.data))
-	streams := edc.Items()
-	suite.Equal(expected, len(streams))
-	count := 0
-	for item := range streams {
-		assert.NotNil(suite.T(), item)
-		count++
-	}
-	suite.Equal(count, expected)
-}
-
 func (suite *ExchangeDataCollectionSuite) TestExchangeCollection_AddJob() {
-	eoc := NewCollection("Dexter", []string{"Today", "is", "was", "different"})
+	eoc := Collection{
+		user:     "Dexter",
+		fullPath: []string{"Today", "is", "currently", "different"},
+	}
 	suite.Zero(len(eoc.jobs))
 	shopping := []string{"tomotoes", "potatoes", "pasta", "ice tea"}
 	for _, item := range shopping {

src/internal/connector/graph_connector.go

@@ -325,16 +325,24 @@ func (gc *GraphConnector) serializeMessages(ctx context.Context, user string) (m
 	}
 	// Create collection of ExchangeDataCollection and create  data Holder
 	collections := make(map[string]*exchange.Collection)
+	var errs error
+	// callbackFunc iterates through all models.Messageable and fills exchange.Collection.jobs[]
+	// with corresponding messageIDs. New collections are created for each directory
 	callbackFunc := func(messageItem any) bool {
 		message, ok := messageItem.(models.Messageable)
 		if !ok {
-			err = support.WrapAndAppendf(gc.graphService.adapter.GetBaseUrl(), errors.New("message iteration failure"), err)
+			errs = support.WrapAndAppendf(gc.graphService.adapter.GetBaseUrl(), errors.New("message iteration failure"), err)
 			return true
 		}
 		// Saving to messages to list. Indexed by folder
 		directory := *message.GetParentFolderId()
 		if _, ok = collections[directory]; !ok {
-			edc := exchange.NewCollection(user, []string{gc.tenant, user, mailCategory, directory})
+			service, err := gc.createService(gc.failFast)
+			if err != nil {
+				errs = support.WrapAndAppend(user, err, errs)
+				return true
+			}
+			edc := exchange.NewCollection(user, []string{gc.tenant, user, mailCategory, directory}, service, gc.statusCh)
 			collections[directory] = &edc
 		}
 		collections[directory].AddJob(*message.GetId())
@@ -342,22 +350,17 @@ func (gc *GraphConnector) serializeMessages(ctx context.Context, user string) (m
 	}
 	iterateError := pageIterator.Iterate(callbackFunc)
 	if iterateError != nil {
-		err = support.WrapAndAppend(gc.graphService.adapter.GetBaseUrl(), iterateError, err)
+		errs = support.WrapAndAppend(gc.graphService.adapter.GetBaseUrl(), iterateError, errs)
 	}
-	if err != nil {
-		return nil, err // return error if snapshot is incomplete
+	if errs != nil {
+		return nil, errs // return error if snapshot is incomplete
 	}
 
-	service, err := gc.createService(gc.failFast)
-	if err != nil {
-		return nil, support.WrapAndAppend(user, err, err)
-	}
-	for _, edc := range collections {
-		go edc.PopulateFromCollection(ctx, service, gc.statusCh)
+	for range collections {
 		gc.incrementAwaitingMessages()
 	}
 
-	return collections, err
+	return collections, errs
 }
 
 // AwaitStatus updates status field based on item within statusChannel.

src/internal/connector/graph_connector_disconnected_test.go

@@ -9,7 +9,7 @@ import (
 	"github.com/stretchr/testify/require"
 	"github.com/stretchr/testify/suite"
 
-	"github.com/alcionai/corso/internal/connector/exchange"
+	"github.com/alcionai/corso/internal/connector/mockconnector"
 	"github.com/alcionai/corso/internal/connector/support"
 	"github.com/alcionai/corso/internal/data"
 	"github.com/alcionai/corso/pkg/account"
@@ -86,8 +86,8 @@ func (suite *DisconnectedGraphConnectorSuite) TestBuild() {
 
 func (suite *DisconnectedGraphConnectorSuite) TestInterfaceAlignment() {
 	var dc data.Collection
-	concrete := exchange.NewCollection("Check", []string{"interface", "works"})
-	dc = &concrete
+	concrete := mockconnector.NewMockExchangeCollection([]string{"a", "path"}, 1)
+	dc = concrete
 	assert.NotNil(suite.T(), dc)
 
 }

src/internal/connector/graph_connector_test.go

@@ -1,6 +1,7 @@
 package connector
 
 import (
+	"bytes"
 	"context"
 	"testing"
 
@@ -65,6 +66,13 @@ func (suite *GraphConnectorIntegrationSuite) TestGraphConnector_ExchangeDataColl
 	assert.Nil(suite.T(), err)
 	assert.True(suite.T(), suite.connector.awaitingMessages > 0)
 	assert.Nil(suite.T(), suite.connector.status)
+	// Verify Items() call returns an iterable channel(e.g. a channel that has been closed)
+	channel := collectionList[0].Items()
+	for object := range channel {
+		buf := &bytes.Buffer{}
+		_, err := buf.ReadFrom(object.ToReader())
+		assert.Nil(suite.T(), err, "received a buf.Read error")
+	}
 	status := suite.connector.AwaitStatus()
 	assert.NotNil(suite.T(), status, "status not blocking on async call")