Move stateOf to data (#2455)

## Description

stateOf needs to be used in more places. Move it to a common location so  as to expose it.

## 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
- [ ] 🤖 Test
- [ ] 💻 CI/Deployment
- [x] 🧹 Tech Debt/Cleanup

## Issue(s)

<!-- Can reference multiple issues. Use one of the following "magic words" - "closes, fixes" to auto-close the Github issue. -->
*https://github.com/alcionai/corso/pull/2407

## Test Plan

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

src/internal/connector/exchange/exchange_data_collection.go

@@ -107,7 +107,7 @@ func NewCollection(
 		added:           make(map[string]struct{}, 0),
 		removed:         make(map[string]struct{}, 0),
 		prevPath:        prev,
-		state:           stateOf(prev, curr),
+		state:           data.StateOf(prev, curr),
 		statusUpdater:   statusUpdater,
 		user:            user,
 		items:           items,
@@ -116,22 +116,6 @@ func NewCollection(
 	return collection
 }
 
-func stateOf(prev, curr path.Path) data.CollectionState {
-	if curr == nil || len(curr.String()) == 0 {
-		return data.DeletedState
-	}
-
-	if prev == nil || len(prev.String()) == 0 {
-		return data.NewState
-	}
-
-	if curr.Folder() != prev.Folder() {
-		return data.MovedState
-	}
-
-	return data.NotMovedState
-}
-
 // Items utility function to asynchronously execute process to fill data channel with
 // M365 exchange objects and returns the data channel
 func (col *Collection) Items() <-chan data.Stream {

src/internal/connector/exchange/exchange_data_collection_test.go

@@ -12,10 +12,8 @@ import (
 
 	"github.com/alcionai/corso/src/internal/common"
 	"github.com/alcionai/corso/src/internal/connector/graph"
-	"github.com/alcionai/corso/src/internal/data"
 	"github.com/alcionai/corso/src/internal/tester"
 	"github.com/alcionai/corso/src/pkg/backup/details"
-	"github.com/alcionai/corso/src/pkg/control"
 	"github.com/alcionai/corso/src/pkg/path"
 )
 
@@ -118,59 +116,6 @@ func (suite *ExchangeDataCollectionSuite) TestExchangeDataCollection_NewExchange
 	suite.Equal(fullPath, edc.FullPath())
 }
 
-func (suite *ExchangeDataCollectionSuite) TestNewCollection_state() {
-	fooP, err := path.Builder{}.
-		Append("foo").
-		ToDataLayerExchangePathForCategory("t", "u", path.EmailCategory, false)
-	require.NoError(suite.T(), err)
-	barP, err := path.Builder{}.
-		Append("bar").
-		ToDataLayerExchangePathForCategory("t", "u", path.EmailCategory, false)
-	require.NoError(suite.T(), err)
-
-	table := []struct {
-		name   string
-		prev   path.Path
-		curr   path.Path
-		expect data.CollectionState
-	}{
-		{
-			name:   "new",
-			curr:   fooP,
-			expect: data.NewState,
-		},
-		{
-			name:   "not moved",
-			prev:   fooP,
-			curr:   fooP,
-			expect: data.NotMovedState,
-		},
-		{
-			name:   "moved",
-			prev:   fooP,
-			curr:   barP,
-			expect: data.MovedState,
-		},
-		{
-			name:   "deleted",
-			prev:   fooP,
-			expect: data.DeletedState,
-		},
-	}
-	for _, test := range table {
-		suite.T().Run(test.name, func(t *testing.T) {
-			c := NewCollection(
-				"u",
-				test.curr, test.prev,
-				0,
-				&mockItemer{}, nil,
-				control.Options{},
-				false)
-			assert.Equal(t, test.expect, c.State())
-		})
-	}
-}
-
 func (suite *ExchangeDataCollectionSuite) TestGetItemWithRetries() {
 	table := []struct {
 		name           string

src/internal/data/data_collection.go

@@ -112,3 +112,21 @@ type StreamSize interface {
 type StreamModTime interface {
 	ModTime() time.Time
 }
+
+// StateOf lets us figure out the state of the collection from the
+// previous and current path
+func StateOf(prev, curr path.Path) CollectionState {
+	if curr == nil || len(curr.String()) == 0 {
+		return DeletedState
+	}
+
+	if prev == nil || len(prev.String()) == 0 {
+		return NewState
+	}
+
+	if curr.Folder() != prev.Folder() {
+		return MovedState
+	}
+
+	return NotMovedState
+}

src/internal/data/data_collection_test.go

@@ -0,0 +1,66 @@
+package data
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+	"github.com/stretchr/testify/suite"
+
+	"github.com/alcionai/corso/src/pkg/path"
+)
+
+type DataCollectionSuite struct {
+	suite.Suite
+}
+
+func TestDataCollectionSuite(t *testing.T) {
+	suite.Run(t, new(DataCollectionSuite))
+}
+
+func (suite *DataCollectionSuite) TestStateOf() {
+	fooP, err := path.Builder{}.
+		Append("foo").
+		ToDataLayerExchangePathForCategory("t", "u", path.EmailCategory, false)
+	require.NoError(suite.T(), err)
+	barP, err := path.Builder{}.
+		Append("bar").
+		ToDataLayerExchangePathForCategory("t", "u", path.EmailCategory, false)
+	require.NoError(suite.T(), err)
+
+	table := []struct {
+		name   string
+		prev   path.Path
+		curr   path.Path
+		expect CollectionState
+	}{
+		{
+			name:   "new",
+			curr:   fooP,
+			expect: NewState,
+		},
+		{
+			name:   "not moved",
+			prev:   fooP,
+			curr:   fooP,
+			expect: NotMovedState,
+		},
+		{
+			name:   "moved",
+			prev:   fooP,
+			curr:   barP,
+			expect: MovedState,
+		},
+		{
+			name:   "deleted",
+			prev:   fooP,
+			expect: DeletedState,
+		},
+	}
+	for _, test := range table {
+		suite.T().Run(test.name, func(t *testing.T) {
+			state := StateOf(test.prev, test.curr)
+			assert.Equal(t, test.expect, state)
+		})
+	}
+}