remove all uses of iota (#4046)

I've needed to catch gotchas that arise from contributors adding a value in the middle of an iota list, not to mention have dealt with prior bugs that happened the same way, now too many times to feel safe about its usage.

This PR removes the use of iota from all const declarations. The intent is to not allow the use of iota within the codebase.

---

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

- [x] ⛔ No

#### Type of change

- [x] 🧹 Tech Debt/Cleanup

#### Issue(s)

* #3993

#### Test Plan

- [x] ⚡ Unit test
- [x] 💚 E2E

src/internal/data/implementations.go

@@ -13,10 +13,10 @@ var ErrNotFound = clues.New("not found")
 type CollectionState int
 
 const (
-	NewState = CollectionState(iota)
-	NotMovedState
-	MovedState
-	DeletedState
+	NewState      CollectionState = 0
+	NotMovedState CollectionState = 1
+	MovedState    CollectionState = 2
+	DeletedState  CollectionState = 3
 )
 
 type FetchRestoreCollection struct {

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

@@ -31,13 +31,13 @@ type collectionScope int
 const (
 	// CollectionScopeUnknown is used when we don't know and don't need
 	// to know the kind, like in the case of deletes
-	CollectionScopeUnknown collectionScope = iota
+	CollectionScopeUnknown collectionScope = 0
 
 	// CollectionScopeFolder is used for regular folder collections
-	CollectionScopeFolder
+	CollectionScopeFolder collectionScope = 1
 
 	// CollectionScopePackage is used to represent OneNote items
-	CollectionScopePackage
+	CollectionScopePackage collectionScope = 2
 )
 
 const restrictedDirectory = "Site Pages"

src/internal/m365/collection/drive/metadata/permissions.go

@@ -14,8 +14,8 @@ import (
 type SharingMode int
 
 const (
-	SharingModeCustom = SharingMode(iota)
-	SharingModeInherited
+	SharingModeCustom    SharingMode = 0
+	SharingModeInherited SharingMode = 1
 )
 
 type GV2Type string

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

@@ -59,6 +59,7 @@ func CollectPages(
 	bpc inject.BackupProducerConfig,
 	creds account.M365Config,
 	ac api.Client,
+	scope selectors.SharePointScope,
 	su support.StatusUpdater,
 	errs *fault.Bus,
 ) ([]data.BackupCollection, error) {
@@ -105,7 +106,7 @@ func CollectPages(
 		collection := NewCollection(
 			dir,
 			ac,
-			Pages,
+			scope,
 			su,
 			bpc.Options)
 		collection.SetBetaService(betaService)
@@ -122,6 +123,7 @@ func CollectLists(
 	bpc inject.BackupProducerConfig,
 	ac api.Client,
 	tenantID string,
+	scope selectors.SharePointScope,
 	su support.StatusUpdater,
 	errs *fault.Bus,
 ) ([]data.BackupCollection, error) {
@@ -156,7 +158,7 @@ func CollectLists(
 		collection := NewCollection(
 			dir,
 			ac,
-			List,
+			scope,
 			su,
 			bpc.Options)
 		collection.AddJob(tuple.ID)

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

@@ -16,6 +16,7 @@ import (
 	"github.com/alcionai/corso/src/internal/version"
 	"github.com/alcionai/corso/src/pkg/control"
 	"github.com/alcionai/corso/src/pkg/fault"
+	"github.com/alcionai/corso/src/pkg/selectors"
 	"github.com/alcionai/corso/src/pkg/services/m365/api"
 )
 
@@ -61,11 +62,14 @@ func (suite *SharePointPagesSuite) TestCollectPages() {
 		ProtectedResource: mock.NewProvider(siteID, siteID),
 	}
 
+	sel := selectors.NewSharePointBackup([]string{siteID})
+
 	col, err := CollectPages(
 		ctx,
 		bpc,
 		creds,
 		ac,
+		sel.Lists(selectors.Any())[0],
 		(&MockGraphService{}).UpdateStatus,
 		fault.New(true))
 	assert.NoError(t, err, clues.ToCore(err))

src/internal/m365/collection/site/collection.go

@@ -21,19 +21,23 @@ import (
 	"github.com/alcionai/corso/src/pkg/fault"
 	"github.com/alcionai/corso/src/pkg/logger"
 	"github.com/alcionai/corso/src/pkg/path"
+	"github.com/alcionai/corso/src/pkg/selectors"
 	"github.com/alcionai/corso/src/pkg/services/m365/api"
 )
 
 type DataCategory int
 
+// channel sizes
+const (
+	collectionChannelBufferSize = 50
+	fetchChannelSize            = 5
+)
+
 //go:generate stringer -type=DataCategory
 const (
-	collectionChannelBufferSize              = 50
-	fetchChannelSize                         = 5
-	Unknown                     DataCategory = iota
-	List
-	Drive
-	Pages
+	Unknown DataCategory = 0
+	List    DataCategory = 1
+	Pages   DataCategory = 2
 )
 
 var (
@@ -53,7 +57,7 @@ type Collection struct {
 	// jobs contain the SharePoint.Site.ListIDs for the associated list(s).
 	jobs []string
 	// M365 IDs of the items of this collection
-	category      DataCategory
+	category      path.CategoryType
 	client        api.Sites
 	ctrl          control.Options
 	betaService   *betaAPI.BetaService
@@ -64,7 +68,7 @@ type Collection struct {
 func NewCollection(
 	folderPath path.Path,
 	ac api.Client,
-	category DataCategory,
+	scope selectors.SharePointScope,
 	statusUpdater support.StatusUpdater,
 	ctrlOpts control.Options,
 ) *Collection {
@@ -74,7 +78,7 @@ func NewCollection(
 		data:          make(chan data.Item, collectionChannelBufferSize),
 		client:        ac.Sites(),
 		statusUpdater: statusUpdater,
-		category:      category,
+		category:      scope.Category().PathType(),
 		ctrl:          ctrlOpts,
 	}
 
@@ -198,9 +202,9 @@ func (sc *Collection) runPopulate(
 
 	// Switch retrieval function based on category
 	switch sc.category {
-	case List:
+	case path.ListsCategory:
 		metrics, err = sc.retrieveLists(ctx, writer, colProgress, errs)
-	case Pages:
+	case path.PagesCategory:
 		metrics, err = sc.retrievePages(ctx, sc.client, writer, colProgress, errs)
 	}
 

src/internal/m365/collection/site/collection_test.go

@@ -23,6 +23,7 @@ import (
 	"github.com/alcionai/corso/src/pkg/control/testdata"
 	"github.com/alcionai/corso/src/pkg/fault"
 	"github.com/alcionai/corso/src/pkg/path"
+	"github.com/alcionai/corso/src/pkg/selectors"
 	"github.com/alcionai/corso/src/pkg/services/m365/api"
 )
 
@@ -82,16 +83,18 @@ func (suite *SharePointCollectionSuite) TestCollection_Items() {
 		dirRoot = "directory"
 	)
 
+	sel := selectors.NewSharePointBackup([]string{"site"})
+
 	tables := []struct {
 		name, itemName string
-		category       DataCategory
+		scope          selectors.SharePointScope
 		getDir         func(t *testing.T) path.Path
 		getItem        func(t *testing.T, itemName string) *Item
 	}{
 		{
 			name:     "List",
 			itemName: "MockListing",
-			category: List,
+			scope:    sel.Lists(selectors.Any())[0],
 			getDir: func(t *testing.T) path.Path {
 				dir, err := path.Build(
 					tenant,
@@ -127,7 +130,7 @@ func (suite *SharePointCollectionSuite) TestCollection_Items() {
 		{
 			name:     "Pages",
 			itemName: "MockPages",
-			category: Pages,
+			scope:    sel.Pages(selectors.Any())[0],
 			getDir: func(t *testing.T) path.Path {
 				dir, err := path.Build(
 					tenant,
@@ -166,7 +169,7 @@ func (suite *SharePointCollectionSuite) TestCollection_Items() {
 			col := NewCollection(
 				test.getDir(t),
 				suite.ac,
-				test.category,
+				test.scope,
 				nil,
 				control.DefaultOptions())
 			col.data <- test.getItem(t, test.itemName)

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

@@ -63,6 +63,7 @@ func ProduceBackupCollections(
 				bpc,
 				ac,
 				creds.AzureTenantID,
+				scope,
 				su,
 				errs)
 			if err != nil {
@@ -95,6 +96,7 @@ func ProduceBackupCollections(
 				bpc,
 				creds,
 				ac,
+				scope,
 				su,
 				errs)
 			if err != nil {

src/internal/m365/support/status.go

@@ -37,10 +37,10 @@ type Operation int
 
 //go:generate stringer -type=Operation
 const (
-	OpUnknown Operation = iota
-	Backup
-	Restore
-	Export
+	OpUnknown Operation = 0
+	Backup    Operation = 1
+	Restore   Operation = 2
+	Export    Operation = 3
 )
 
 // Constructor for ConnectorOperationStatus. If the counts do not agree, an error is returned.

src/internal/model/model.go

@@ -22,12 +22,12 @@ func (id StableID) String() string {
 //
 //go:generate go run golang.org/x/tools/cmd/stringer -type=Schema
 const (
-	UnknownSchema = Schema(iota)
-	BackupOpSchema
-	RestoreOpSchema
-	BackupSchema
-	BackupDetailsSchema
-	RepositorySchema
+	UnknownSchema       Schema = 0
+	BackupOpSchema      Schema = 1
+	RestoreOpSchema     Schema = 2
+	BackupSchema        Schema = 3
+	BackupDetailsSchema Schema = 4
+	RepositorySchema    Schema = 5
 )
 
 // common tags for filtering
@@ -38,7 +38,7 @@ const (
 	MergeBackup   = "merge-backup"
 )
 
-// Valid returns true if the ModelType value fits within the iota range.
+// Valid returns true if the ModelType value fits within the const range.
 func (mt Schema) Valid() bool {
 	return mt > 0 && mt < RepositorySchema+1
 }

src/internal/operations/operation.go

@@ -33,11 +33,11 @@ type OpStatus int
 
 //go:generate stringer -type=OpStatus -linecomment
 const (
-	Unknown    OpStatus = iota // Status Unknown
-	InProgress                 // In Progress
-	Completed                  // Completed
-	Failed                     // Failed
-	NoData                     // No Data
+	Unknown    OpStatus = 0 // Status Unknown
+	InProgress OpStatus = 1 // In Progress
+	Completed  OpStatus = 2 // Completed
+	Failed     OpStatus = 3 // Failed
+	NoData     OpStatus = 4 // No Data
 )
 
 // --------------------------------------------------------------------------------

src/pkg/account/account.go

@@ -10,8 +10,8 @@ type accountProvider int
 
 //go:generate stringer -type=accountProvider -linecomment
 const (
-	ProviderUnknown accountProvider = iota // Unknown Provider
-	ProviderM365                           // M365
+	ProviderUnknown accountProvider = 0 // Unknown Provider
+	ProviderM365    accountProvider = 1 // M365
 )
 
 // storage parsing errors

src/pkg/backup/details/iteminfo.go

@@ -20,16 +20,17 @@ type ItemType int
 // Additionally, any itemType directly assigned a number should not be altered.
 // This applies to  OneDriveItem and FolderItem
 const (
-	UnknownType ItemType = iota // 0, global unknown value
+	UnknownType ItemType = 0
 
 	// Exchange (00x)
-	ExchangeContact
-	ExchangeEvent
-	ExchangeMail
+	ExchangeContact ItemType = 1
+	ExchangeEvent   ItemType = 2
+	ExchangeMail    ItemType = 3
+
 	// SharePoint (10x)
-	SharePointLibrary ItemType = iota + 97 // 100
-	SharePointList                         // 101...
-	SharePointPage
+	SharePointLibrary ItemType = 101
+	SharePointList    ItemType = 102
+	SharePointPage    ItemType = 103
 
 	// OneDrive (20x)
 	OneDriveItem ItemType = 205

src/pkg/control/repository/repo.go

@@ -25,12 +25,10 @@ type Maintenance struct {
 
 type MaintenanceType int
 
-// Can't be reordered as we rely on iota for numbering.
-//
 //go:generate stringer -type=MaintenanceType -linecomment
 const (
-	CompleteMaintenance MaintenanceType = iota // complete
-	MetadataMaintenance                        // metadata
+	CompleteMaintenance MaintenanceType = 0 // complete
+	MetadataMaintenance MaintenanceType = 1 // metadata
 )
 
 var StringToMaintenanceType = map[string]MaintenanceType{
@@ -40,16 +38,14 @@ var StringToMaintenanceType = map[string]MaintenanceType{
 
 type MaintenanceSafety int
 
-// Can't be reordered as we rely on iota for numbering.
-//
 //go:generate stringer -type=MaintenanceSafety -linecomment
 const (
-	FullMaintenanceSafety MaintenanceSafety = iota
+	FullMaintenanceSafety MaintenanceSafety = 0
 	//nolint:lll
 	// Use only if there's no other kopia instances accessing the repo and the
 	// storage backend is strongly consistent.
 	// https://github.com/kopia/kopia/blob/f9de453efc198b6e993af8922f953a7e5322dc5f/repo/maintenance/maintenance_safety.go#L42
-	NoMaintenanceSafety
+	NoMaintenanceSafety MaintenanceSafety = 1
 )
 
 type RetentionMode int