provisions to identify fields with multiple value (#5109)

provisions to identify fields with multiple value.
Some fields can hold multiple values and single value based on a property called `allowMultipleValues`.
For example, `Lookup` column:
```
"lookup": {
    "allowMultipleValues": true,
    "allowUnlimitedLength": false,
    "columnName": "Title",
    "listId": "21b45bf2-e495-4582-b114-839577ff8e4f"
}
```
But `choice` columns, even though allows to set multiple choices/value, does not have that particular field `allowMultipleValues` to indicate.
So in this PR we are trying determine the same by the stored values while restoring.

**Original list with `choice` column in site**:
![Choice-List-Multi](https://github.com/alcionai/corso/assets/48874082/d4457b3c-0230-4a69-8467-f64b7d7d4f04)

**Restored list with `choice` column in site**
![Restored-Choice-List-Multi](https://github.com/alcionai/corso/assets/48874082/78478055-0e84-43d0-ac83-262b564ce778)
The color does not come through though


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

#### Issue(s)
#5108 

#### Test Plan

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

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

@@ -61,6 +61,9 @@ const (
 	ChildCountFieldNamePart = "ChildCount"
 	LookupIDFieldNamePart   = "LookupId"
 
+	ODataTypeFieldNamePart      = "@odata.type"
+	ODataTypeFieldNameStringVal = "Collection(Edm.String)"
+
 	ReadOnlyOrHiddenFieldNamePrefix = "_"
 	DescoratorFieldNamePrefix       = "@"
 

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

@@ -3,6 +3,7 @@ package api
 import (
 	"context"
 	"fmt"
+	"reflect"
 	"strings"
 
 	"github.com/alcionai/clues"
@@ -18,6 +19,11 @@ import (
 
 var ErrSkippableListTemplate = clues.New("unable to create lists with skippable templates")
 
+type columnDetails struct {
+	isMultipleEnabled  bool
+	hasDefaultedToText bool
+}
+
 // ---------------------------------------------------------------------------
 // controller
 // ---------------------------------------------------------------------------
@@ -277,7 +283,7 @@ func BytesToListable(bytes []byte) (models.Listable, error) {
 // not attached in this method.
 // ListItems are not included in creation of new list, and have to be restored
 // in separate call.
-func ToListable(orig models.Listable, listName string) (models.Listable, map[string]any) {
+func ToListable(orig models.Listable, listName string) (models.Listable, map[string]*columnDetails) {
 	newList := models.NewList()
 
 	newList.SetContentTypes(orig.GetContentTypes())
@@ -294,7 +300,7 @@ func ToListable(orig models.Listable, listName string) (models.Listable, map[str
 	newList.SetParentReference(orig.GetParentReference())
 
 	columns := make([]models.ColumnDefinitionable, 0)
-	columnNames := map[string]any{TitleColumnName: nil}
+	columnNames := map[string]*columnDetails{TitleColumnName: {}}
 
 	for _, cd := range orig.GetColumns() {
 		var (
@@ -316,8 +322,7 @@ func ToListable(orig models.Listable, listName string) (models.Listable, map[str
 			continue
 		}
 
-		columns = append(columns, cloneColumnDefinitionable(cd))
+		columns = append(columns, cloneColumnDefinitionable(cd, columnNames))
-		columnNames[ptr.Val(cd.GetName())] = nil
 	}
 
 	newList.SetColumns(columns)
@@ -327,7 +332,10 @@ func ToListable(orig models.Listable, listName string) (models.Listable, map[str
 
 // cloneColumnDefinitionable utility function for encapsulating models.ColumnDefinitionable data
 // into new object for upload.
-func cloneColumnDefinitionable(orig models.ColumnDefinitionable) models.ColumnDefinitionable {
+func cloneColumnDefinitionable(
+	orig models.ColumnDefinitionable,
+	columnNames map[string]*columnDetails,
+) models.ColumnDefinitionable {
 	newColumn := models.NewColumnDefinition()
 
 	// column attributes
@@ -351,7 +359,7 @@ func cloneColumnDefinitionable(orig models.ColumnDefinitionable) models.ColumnDe
 	newColumn.SetEnforceUniqueValues(orig.GetEnforceUniqueValues())
 
 	// column types
-	setColumnType(newColumn, orig)
+	setColumnType(newColumn, orig, columnNames)
 
 	// Requires nil checks to avoid Graph error: 'General exception while processing'
 	defaultValue := orig.GetDefaultValue()
@@ -367,7 +375,13 @@ func cloneColumnDefinitionable(orig models.ColumnDefinitionable) models.ColumnDe
 	return newColumn
 }
 
-func setColumnType(newColumn *models.ColumnDefinition, orig models.ColumnDefinitionable) {
+func setColumnType(
+	newColumn *models.ColumnDefinition,
+	orig models.ColumnDefinitionable,
+	columnNames map[string]*columnDetails,
+) {
+	colDetails := &columnDetails{}
+
 	switch {
 	case orig.GetText() != nil:
 		newColumn.SetText(orig.GetText())
@@ -398,14 +412,18 @@ func setColumnType(newColumn *models.ColumnDefinition, orig models.ColumnDefinit
 	case orig.GetPersonOrGroup() != nil:
 		newColumn.SetPersonOrGroup(orig.GetPersonOrGroup())
 	default:
+		colDetails.hasDefaultedToText = true
+
 		newColumn.SetText(models.NewTextColumn())
 	}
+
+	columnNames[ptr.Val(newColumn.GetName())] = colDetails
 }
 
 // CloneListItem creates a new `SharePoint.ListItem` and stores the original item's
 // M365 data into it set fields.
 // - https://learn.microsoft.com/en-us/graph/api/resources/listitem?view=graph-rest-1.0
-func CloneListItem(orig models.ListItemable, columnNames map[string]any) models.ListItemable {
+func CloneListItem(orig models.ListItemable, columnNames map[string]*columnDetails) models.ListItemable {
 	newItem := models.NewListItem()
 
 	// list item data
@@ -442,7 +460,7 @@ func CloneListItem(orig models.ListItemable, columnNames map[string]any) models.
 // additionalData map
 // Further documentation on FieldValueSets:
 // - https://learn.microsoft.com/en-us/graph/api/resources/fieldvalueset?view=graph-rest-1.0
-func retrieveFieldData(orig models.FieldValueSetable, columnNames map[string]any) models.FieldValueSetable {
+func retrieveFieldData(orig models.FieldValueSetable, columnNames map[string]*columnDetails) models.FieldValueSetable {
 	fields := models.NewFieldValueSet()
 
 	additionalData := setAdditionalDataByColumnNames(orig, columnNames)
@@ -463,7 +481,7 @@ func retrieveFieldData(orig models.FieldValueSetable, columnNames map[string]any
 
 func setAdditionalDataByColumnNames(
 	orig models.FieldValueSetable,
-	columnNames map[string]any,
+	columnNames map[string]*columnDetails,
 ) map[string]any {
 	if orig == nil {
 		return make(map[string]any)
@@ -472,15 +490,41 @@ func setAdditionalDataByColumnNames(
 	fieldData := orig.GetAdditionalData()
 	filteredData := make(map[string]any)
 
-	for colName := range columnNames {
+	for colName, colDetails := range columnNames {
-		if _, ok := fieldData[colName]; ok {
+		if val, ok := fieldData[colName]; ok {
+			// for columns like 'choice', even though it has an option to hold single/multiple values,
+			// the columnDefinition property 'allowMultipleValues' is not available.
+			// Hence we determine single/multiple from the actual field data.
+			if isSlice(val) {
+				colDetails.isMultipleEnabled = true
+			}
+
 			filteredData[colName] = fieldData[colName]
 		}
+
+		specifyODataType(filteredData, colDetails, colName)
 	}
 
 	return filteredData
 }
 
+// when creating list items with multiple values for a single column
+// we let the API know that we are sending a collection.
+// Hence this adds an additional field '<columnName>@@odata.type'
+// with value depending on type of column.
+func specifyODataType(filteredData map[string]any, colDetails *columnDetails, colName string) {
+	// text column itself does not allow holding multiple values
+	// some columns like 'term'/'managed metadata' have,
+	//  but they get defaulted to text column.
+	if colDetails.hasDefaultedToText {
+		return
+	}
+
+	if colDetails.isMultipleEnabled {
+		filteredData[colName+ODataTypeFieldNamePart] = ODataTypeFieldNameStringVal
+	}
+}
+
 func hasAddressFields(additionalData map[string]any) (map[string]any, string, bool) {
 	for k, v := range additionalData {
 		nestedFields, ok := v.(map[string]any)
@@ -631,3 +675,7 @@ func ListCollisionKey(list models.Listable) string {
 
 	return ptr.Val(list.GetDisplayName())
 }
+
+func isSlice(val any) bool {
+	return reflect.TypeOf(val).Kind() == reflect.Slice
+}

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

@@ -162,12 +162,12 @@ func (suite *ListsUnitSuite) TestColumnDefinitionable_GetValidation() {
 	for _, test := range tests {
 		suite.Run(test.name, func() {
 			t := suite.T()
+			colNames := map[string]*columnDetails{}
 
 			orig := test.getOrig()
-			newCd := cloneColumnDefinitionable(orig)
+			newCd := cloneColumnDefinitionable(orig, colNames)
 
 			require.NotEmpty(t, newCd)
-
 			test.expect(t, newCd.GetValidation())
 		})
 	}
@@ -219,9 +219,10 @@ func (suite *ListsUnitSuite) TestColumnDefinitionable_GetDefaultValue() {
 	for _, test := range tests {
 		suite.Run(test.name, func() {
 			t := suite.T()
+			colNames := map[string]*columnDetails{}
 
 			orig := test.getOrig()
-			newCd := cloneColumnDefinitionable(orig)
+			newCd := cloneColumnDefinitionable(orig, colNames)
 
 			require.NotEmpty(t, newCd)
 			test.expect(t, newCd)
@@ -277,9 +278,8 @@ func (suite *ListsUnitSuite) TestColumnDefinitionable_ColumnType() {
 	for _, test := range tests {
 		suite.Run(test.name, func() {
 			t := suite.T()
-
+			colNames := map[string]*columnDetails{}
-			orig := test.getOrig()
+			newCd := cloneColumnDefinitionable(test.getOrig(), colNames)
-			newCd := cloneColumnDefinitionable(orig)
 
 			require.NotEmpty(t, newCd)
 			assert.True(t, test.checkFn(newCd))
@@ -332,7 +332,7 @@ func (suite *ListsUnitSuite) TestColumnDefinitionable_LegacyColumns() {
 		name             string
 		getList          func() *models.List
 		length           int
-		expectedColNames map[string]any
+		expectedColNames map[string]*columnDetails
 	}{
 		{
 			name: "all legacy columns",
@@ -346,7 +346,7 @@ func (suite *ListsUnitSuite) TestColumnDefinitionable_LegacyColumns() {
 				return lst
 			},
 			length:           0,
-			expectedColNames: map[string]any{TitleColumnName: nil},
+			expectedColNames: map[string]*columnDetails{TitleColumnName: {}},
 		},
 		{
 			name: "title and legacy columns",
@@ -361,7 +361,7 @@ func (suite *ListsUnitSuite) TestColumnDefinitionable_LegacyColumns() {
 				return lst
 			},
 			length:           0,
-			expectedColNames: map[string]any{TitleColumnName: nil},
+			expectedColNames: map[string]*columnDetails{TitleColumnName: {}},
 		},
 		{
 			name: "readonly and legacy columns",
@@ -376,7 +376,7 @@ func (suite *ListsUnitSuite) TestColumnDefinitionable_LegacyColumns() {
 				return lst
 			},
 			length:           0,
-			expectedColNames: map[string]any{TitleColumnName: nil},
+			expectedColNames: map[string]*columnDetails{TitleColumnName: {}},
 		},
 		{
 			name: "legacy and a text column",
@@ -391,9 +391,9 @@ func (suite *ListsUnitSuite) TestColumnDefinitionable_LegacyColumns() {
 				return lst
 			},
 			length: 1,
-			expectedColNames: map[string]any{
+			expectedColNames: map[string]*columnDetails{
-				TitleColumnName: nil,
+				TitleColumnName: {},
-				textColumnName:  nil,
+				textColumnName:  {},
 			},
 		},
 	}
@@ -432,7 +432,7 @@ func (suite *ListsUnitSuite) TestFieldValueSetable() {
 	origFs := models.NewFieldValueSet()
 	origFs.SetAdditionalData(additionalData)
 
-	colNames := map[string]any{}
+	colNames := map[string]*columnDetails{}
 
 	fs := retrieveFieldData(origFs, colNames)
 	fsAdditionalData := fs.GetAdditionalData()
@@ -442,7 +442,7 @@ func (suite *ListsUnitSuite) TestFieldValueSetable() {
 	origFs = models.NewFieldValueSet()
 	origFs.SetAdditionalData(additionalData)
 
-	colNames["itemName"] = struct{}{}
+	colNames["itemName"] = &columnDetails{}
 
 	fs = retrieveFieldData(origFs, colNames)
 	fsAdditionalData = fs.GetAdditionalData()
@@ -509,8 +509,8 @@ func (suite *ListsUnitSuite) TestFieldValueSetable_Location() {
 	origFs := models.NewFieldValueSet()
 	origFs.SetAdditionalData(additionalData)
 
-	colNames := map[string]any{
+	colNames := map[string]*columnDetails{
-		"MyAddress": nil,
+		"MyAddress": {},
 	}
 
 	fs := retrieveFieldData(origFs, colNames)
@@ -703,6 +703,75 @@ func (suite *ListsUnitSuite) TestConcatenateHyperlinkFields() {
 	}
 }
 
+func (suite *ListsUnitSuite) TestSetAdditionalDataByColumnNames() {
+	t := suite.T()
+
+	tests := []struct {
+		name           string
+		additionalData map[string]any
+		colName        string
+		assertFn       assert.BoolAssertionFunc
+	}{
+		{
+			name: "choice column, single value",
+			additionalData: map[string]any{
+				"choice": "good",
+			},
+			colName:  "choice",
+			assertFn: assert.False,
+		},
+		{
+			name: "choice column, multiple values",
+			additionalData: map[string]any{
+				"choice": []string{"good", "ok"},
+			},
+			colName:  "choice",
+			assertFn: assert.True,
+		},
+		{
+			name: "person column, single value",
+			additionalData: map[string]any{
+				"PersonsLookupId": 10,
+			},
+			colName:  "PersonsLookupId",
+			assertFn: assert.False,
+		},
+		{
+			name: "person column, multiple values",
+			additionalData: map[string]any{
+				"Persons": []map[string]any{
+					{
+						"LookupId":    10,
+						"LookupValue": "Who1",
+						"Email":       "Who1@10rqc2.onmicrosoft.com",
+					},
+					{
+						"LookupId":    11,
+						"LookupValue": "Who2",
+						"Email":       "Who2@10rqc2.onmicrosoft.com",
+					},
+				},
+			},
+			colName:  "Persons",
+			assertFn: assert.True,
+		},
+	}
+
+	for _, test := range tests {
+		origFs := models.NewFieldValueSet()
+		origFs.SetAdditionalData(test.additionalData)
+
+		colNames := map[string]*columnDetails{
+			test.colName: {},
+		}
+
+		suite.Run(test.name, func() {
+			setAdditionalDataByColumnNames(origFs, colNames)
+			test.assertFn(t, colNames[test.colName].isMultipleEnabled)
+		})
+	}
+}
+
 type ListsAPIIntgSuite struct {
 	tester.Suite
 	its intgTesterSetup