remove operation "started" (#2247)

## Description

This flag is confusing, and is better represented by
tracking errors.

## Type of change

- [x] 🧹 Tech Debt/Cleanup

## Test Plan

- [x] ⚡ Unit test

src/internal/operations/backup.go

@@ -90,7 +90,6 @@ type backupStats struct {
 	k                 *kopia.BackupStats
 	gc                *support.ConnectorOperationStatus
 	resourceCount     int
-	started           bool
 	readErr, writeErr error
 }
 
@@ -228,7 +227,6 @@ func (op *BackupOperation) Run(ctx context.Context) (err error) {
 
 	// should always be 1, since backups are 1:1 with resourceOwners.
 	opStats.resourceCount = 1
-	opStats.started = true
 
 	return err
 }
@@ -558,9 +556,12 @@ func (op *BackupOperation) persistResults(
 ) error {
 	op.Results.StartedAt = started
 	op.Results.CompletedAt = time.Now()
+	op.Results.ReadErrors = opStats.readErr
+	op.Results.WriteErrors = opStats.writeErr
 
 	op.Status = Completed
-	if !opStats.started {
+
+	if opStats.readErr != nil || opStats.writeErr != nil {
 		op.Status = Failed
 
 		return multierror.Append(
@@ -573,9 +574,6 @@ func (op *BackupOperation) persistResults(
 		op.Status = NoData
 	}
 
-	op.Results.ReadErrors = opStats.readErr
-	op.Results.WriteErrors = opStats.writeErr
-
 	op.Results.BytesRead = opStats.k.TotalHashedBytes
 	op.Results.BytesUploaded = opStats.k.TotalUploadedBytes
 	op.Results.ItemsRead = opStats.gc.Successful

src/internal/operations/backup_test.go

@@ -373,7 +373,6 @@ func (suite *BackupOpSuite) TestBackupOperation_PersistResults() {
 			expectStatus: Completed,
 			expectErr:    assert.NoError,
 			stats: backupStats{
-				started:       true,
 				resourceCount: 1,
 				k: &kopia.BackupStats{
 					TotalFileCount:     1,
@@ -389,7 +388,7 @@ func (suite *BackupOpSuite) TestBackupOperation_PersistResults() {
 			expectStatus: Failed,
 			expectErr:    assert.Error,
 			stats: backupStats{
-				started: false,
+				readErr: assert.AnError,
 				k:       &kopia.BackupStats{},
 				gc:      &support.ConnectorOperationStatus{},
 			},
@@ -398,7 +397,6 @@ func (suite *BackupOpSuite) TestBackupOperation_PersistResults() {
 			expectStatus: NoData,
 			expectErr:    assert.NoError,
 			stats: backupStats{
-				started: true,
 				k:  &kopia.BackupStats{},
 				gc: &support.ConnectorOperationStatus{},
 			},

src/internal/operations/restore.go

@@ -89,7 +89,6 @@ type restoreStats struct {
 	gc                *support.ConnectorOperationStatus
 	bytesRead         *stats.ByteCounter
 	resourceCount     int
-	started           bool
 	readErr, writeErr error
 
 	// a transient value only used to pair up start-end events.
@@ -143,10 +142,8 @@ func (op *RestoreOperation) Run(ctx context.Context) (restoreDetails *details.De
 		detailsStore,
 	)
 	if err != nil {
-		err = errors.Wrap(err, "restore")
+		opStats.readErr = errors.Wrap(err, "restore")
-		opStats.readErr = err
+		return nil, opStats.readErr
-
-		return nil, err
 	}
 
 	ctx = clues.Add(ctx, "resource_owner", bup.Selector.DiscreteOwner)
@@ -178,10 +175,8 @@ func (op *RestoreOperation) Run(ctx context.Context) (restoreDetails *details.De
 
 	dcs, err := op.kopia.RestoreMultipleItems(ctx, bup.SnapshotID, paths, opStats.bytesRead)
 	if err != nil {
-		err = errors.Wrap(err, "retrieving service data")
+		opStats.readErr = errors.Wrap(err, "retrieving service data")
-		opStats.readErr = err
+		return nil, opStats.readErr
-
-		return nil, err
 	}
 	kopiaComplete <- struct{}{}
 
@@ -207,14 +202,11 @@ func (op *RestoreOperation) Run(ctx context.Context) (restoreDetails *details.De
 		op.Destination,
 		dcs)
 	if err != nil {
-		err = errors.Wrap(err, "restoring service data")
+		opStats.writeErr = errors.Wrap(err, "restoring service data")
-		opStats.writeErr = err
+		return nil, opStats.writeErr
-
-		return nil, err
 	}
 	restoreComplete <- struct{}{}
 
-	opStats.started = true
 	opStats.gc = gc.AwaitStatus()
 
 	logger.Ctx(ctx).Debug(gc.PrintableStatus())
@@ -230,10 +222,12 @@ func (op *RestoreOperation) persistResults(
 ) error {
 	op.Results.StartedAt = started
 	op.Results.CompletedAt = time.Now()
+	op.Results.ReadErrors = opStats.readErr
+	op.Results.WriteErrors = opStats.writeErr
 
 	op.Status = Completed
 
-	if !opStats.started {
+	if opStats.readErr != nil || opStats.writeErr != nil {
 		op.Status = Failed
 
 		return multierror.Append(
@@ -246,9 +240,6 @@ func (op *RestoreOperation) persistResults(
 		op.Status = NoData
 	}
 
-	op.Results.ReadErrors = opStats.readErr
-	op.Results.WriteErrors = opStats.writeErr
-
 	op.Results.BytesRead = opStats.bytesRead.NumBytes
 	op.Results.ItemsRead = len(opStats.cs) // TODO: file count, not collection count
 	op.Results.ItemsWritten = opStats.gc.Successful

src/internal/operations/restore_test.go

@@ -57,7 +57,6 @@ func (suite *RestoreOpSuite) TestRestoreOperation_PersistResults() {
 			expectStatus: Completed,
 			expectErr:    assert.NoError,
 			stats: restoreStats{
-				started:       true,
 				resourceCount: 1,
 				bytesRead: &stats.ByteCounter{
 					NumBytes: 42,
@@ -73,7 +72,7 @@ func (suite *RestoreOpSuite) TestRestoreOperation_PersistResults() {
 			expectStatus: Failed,
 			expectErr:    assert.Error,
 			stats: restoreStats{
-				started:   false,
+				readErr:   assert.AnError,
 				bytesRead: &stats.ByteCounter{},
 				gc:        &support.ConnectorOperationStatus{},
 			},
@@ -82,7 +81,6 @@ func (suite *RestoreOpSuite) TestRestoreOperation_PersistResults() {
 			expectStatus: NoData,
 			expectErr:    assert.NoError,
 			stats: restoreStats{
-				started:   true,
 				bytesRead: &stats.ByteCounter{},
 				cs:        []data.Collection{},
 				gc:        &support.ConnectorOperationStatus{},