Add CLI flag for disabling assist-incrementals (#3984)

Adds hidden flag for disabling
kopia-assisted incrementals

---

#### 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

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

#### Issue(s)

* closes #2360

#### Test Plan

- [x] 💪 Manual
- [x] ⚡ Unit test
- [ ] 💚 E2E

src/cli/backup/exchange.go

@@ -91,6 +91,7 @@ func addExchangeCommands(cmd *cobra.Command) *cobra.Command {
 		flags.AddFetchParallelismFlag(c)
 		flags.AddFailFastFlag(c)
 		flags.AddDisableIncrementalsFlag(c)
+		flags.AddForceItemDataDownloadFlag(c)
 		flags.AddDisableDeltaFlag(c)
 		flags.AddEnableImmutableIDFlag(c)
 		flags.AddDisableConcurrencyLimiterFlag(c)

src/cli/backup/onedrive.go

@@ -78,6 +78,7 @@ func addOneDriveCommands(cmd *cobra.Command) *cobra.Command {
 
 		flags.AddFailFastFlag(c)
 		flags.AddDisableIncrementalsFlag(c)
+		flags.AddForceItemDataDownloadFlag(c)
 
 	case listCommand:
 		c, fs = utils.AddCommand(cmd, oneDriveListCmd())

src/cli/backup/sharepoint.go

@@ -93,6 +93,7 @@ func addSharePointCommands(cmd *cobra.Command) *cobra.Command {
 		flags.AddDataFlag(c, []string{dataLibraries}, true)
 		flags.AddFailFastFlag(c)
 		flags.AddDisableIncrementalsFlag(c)
+		flags.AddForceItemDataDownloadFlag(c)
 
 	case listCommand:
 		c, fs = utils.AddCommand(cmd, sharePointListCmd())

src/cli/flags/options.go

@@ -9,6 +9,7 @@ const (
 	DisableConcurrencyLimiterFN = "disable-concurrency-limiter"
 	DisableDeltaFN              = "disable-delta"
 	DisableIncrementalsFN       = "disable-incrementals"
+	ForceItemDataDownloadFN     = "force-item-data-download"
 	EnableImmutableIDFN         = "enable-immutable-id"
 	FailFastFN                  = "fail-fast"
 	FailedItemsFN               = "failed-items"
@@ -26,6 +27,7 @@ var (
 	DisableConcurrencyLimiterFV bool
 	DisableDeltaFV              bool
 	DisableIncrementalsFV       bool
+	ForceItemDataDownloadFV     bool
 	EnableImmutableIDFV         bool
 	FailFastFV                  bool
 	FetchParallelismFV          int
@@ -110,6 +112,19 @@ func AddDisableIncrementalsFlag(cmd *cobra.Command) {
 	cobra.CheckErr(fs.MarkHidden(DisableIncrementalsFN))
 }
 
+// Adds the hidden '--force-item-data-download' cli flag which, when set,
+// disables kopia-assisted incremental backups.
+func AddForceItemDataDownloadFlag(cmd *cobra.Command) {
+	fs := cmd.Flags()
+	fs.BoolVar(
+		&ForceItemDataDownloadFV,
+		ForceItemDataDownloadFN,
+		false,
+		"Disable cached data checks in backups to force item redownloads for "+
+			"items changed since the last successful backup.")
+	cobra.CheckErr(fs.MarkHidden(ForceItemDataDownloadFN))
+}
+
 // Adds the hidden '--disable-delta' cli flag which, when set, disables
 // delta based backups.
 func AddDisableDeltaFlag(cmd *cobra.Command) {

src/cli/utils/options.go

@@ -23,6 +23,7 @@ func Control() control.Options {
 	opt.DisableMetrics = flags.NoStatsFV
 	opt.SkipReduce = flags.SkipReduceFV
 	opt.ToggleFeatures.DisableIncrementals = flags.DisableIncrementalsFV
+	opt.ToggleFeatures.ForceItemDataDownload = flags.ForceItemDataDownloadFV
 	opt.ToggleFeatures.DisableDelta = flags.DisableDeltaFV
 	opt.ToggleFeatures.ExchangeImmutableIDs = flags.EnableImmutableIDFV
 	opt.ToggleFeatures.DisableConcurrencyLimiter = flags.DisableConcurrencyLimiterFV

src/cli/utils/options_test.go

@@ -29,6 +29,7 @@ func (suite *OptionsUnitSuite) TestAddExchangeCommands() {
 		Run: func(cmd *cobra.Command, args []string) {
 			assert.True(t, flags.FailFastFV, flags.FailFastFN)
 			assert.True(t, flags.DisableIncrementalsFV, flags.DisableIncrementalsFN)
+			assert.True(t, flags.ForceItemDataDownloadFV, flags.ForceItemDataDownloadFN)
 			assert.True(t, flags.DisableDeltaFV, flags.DisableDeltaFN)
 			assert.True(t, flags.NoStatsFV, flags.NoStatsFN)
 			assert.True(t, flags.RestorePermissionsFV, flags.RestorePermissionsFN)
@@ -44,6 +45,7 @@ func (suite *OptionsUnitSuite) TestAddExchangeCommands() {
 
 	flags.AddFailFastFlag(cmd)
 	flags.AddDisableIncrementalsFlag(cmd)
+	flags.AddForceItemDataDownloadFlag(cmd)
 	flags.AddDisableDeltaFlag(cmd)
 	flags.AddRestorePermissionsFlag(cmd)
 	flags.AddSkipReduceFlag(cmd)
@@ -56,6 +58,7 @@ func (suite *OptionsUnitSuite) TestAddExchangeCommands() {
 		"test",
 		"--" + flags.FailFastFN,
 		"--" + flags.DisableIncrementalsFN,
+		"--" + flags.ForceItemDataDownloadFN,
 		"--" + flags.DisableDeltaFN,
 		"--" + flags.NoStatsFN,
 		"--" + flags.RestorePermissionsFN,