Release 2026.09.27.r002: clarify rsync dry runs and expand run diagnostics

internal/rsync/rsync.go

@@ -40,16 +40,19 @@ type Progress struct {
 	Bytes       int64
 	Files       int64
 	CurrentFile string
+	Change      string
 }
 
 type Summary struct {
-	Bytes int64
-	Files int64
+	Bytes   int64
+	Files   int64
+	Deleted int64
 }
 
 var (
 	progressPattern = regexp.MustCompile(`^\s*([0-9,]+)\s+([0-9]+)%`)
 	filesPattern    = regexp.MustCompile(`^Number of regular files transferred:\s*([0-9,]+)`)
+	deletedPattern  = regexp.MustCompile(`^Number of deleted files:\s*([0-9,]+)`)
 	bytesPattern    = regexp.MustCompile(`^Total transferred file size:\s*([0-9,]+) bytes`)
 )
 
@@ -88,17 +91,12 @@ func (r *Runner) Run(ctx context.Context, runID string, job model.Job, callback
 	done := make(chan struct{})
 	go func() {
 		scanOutput(stdout, func(line string) {
-			if value, ok := parseCount(filesPattern, line); ok {
-				summary.Files = value
-			}
-			if value, ok := parseCount(bytesPattern, line); ok {
-				summary.Bytes = value
-			}
+			summary.parseLine(line)
 			if callback != nil {
 				if progress, ok := parseProgress(line); ok {
 					callback(progress)
-				} else if strings.HasPrefix(line, "FILE|") {
-					callback(Progress{CurrentFile: strings.TrimPrefix(line, "FILE|")})
+				} else if change, ok := parseChange(line); ok {
+					callback(change)
 				}
 			}
 		})
@@ -106,9 +104,10 @@ func (r *Runner) Run(ctx context.Context, runID string, job model.Job, callback
 	}()
 	stderrDone := make(chan []byte, 1)
 	go func() { stderrDone <- drainLimited(stderr, 1024*1024) }()
-	err = cmd.Wait()
+	// Drain both pipes before Wait closes them, including the final statistics.
 	<-done
 	errBytes := <-stderrDone
+	err = cmd.Wait()
 	if err != nil {
 		if errors.Is(ctx.Err(), context.Canceled) {
 			return Summary{}, fmt.Errorf("cancelled: %w", ctx.Err())
@@ -163,20 +162,16 @@ func (r *Runner) Estimate(ctx context.Context, runID string, job model.Job) (Sum
 	done := make(chan struct{})
 	go func() {
 		scanOutput(stdout, func(line string) {
-			if value, ok := parseCount(filesPattern, line); ok {
-				summary.Files = value
-			}
-			if value, ok := parseCount(bytesPattern, line); ok {
-				summary.Bytes = value
-			}
+			summary.parseLine(line)
 		})
 		close(done)
 	}()
 	stderrDone := make(chan []byte, 1)
 	go func() { stderrDone <- drainLimited(stderr, 1024*1024) }()
-	err = cmd.Wait()
+	// Drain both pipes before Wait closes them, including the final statistics.
 	<-done
 	errBytes := <-stderrDone
+	err = cmd.Wait()
 	if err != nil {
 		if errors.Is(ctx.Err(), context.Canceled) {
 			return Summary{}, fmt.Errorf("cancelled: %w", ctx.Err())
@@ -188,7 +183,7 @@ func (r *Runner) Estimate(ctx context.Context, runID string, job model.Job) (Sum
 
 func Arguments(job model.Job) []string {
 	options := job.Rsync
-	args := []string{"--recursive", "--human-readable", "--info=progress2", "--stats", "--partial", "--out-format=FILE|%n"}
+	args := []string{"--recursive", "--info=progress2", "--stats", "--partial", "--outbuf=L", "--out-format=CHANGE|%i|%n%L"}
 	if !options.Overwrite {
 		args = append(args, "--ignore-existing")
 	}
@@ -322,3 +317,26 @@ func parseCount(pattern *regexp.Regexp, line string) (int64, bool) {
 	value, err := strconv.ParseInt(strings.ReplaceAll(match[1], ",", ""), 10, 64)
 	return value, err == nil
 }
+
+func (s *Summary) parseLine(line string) {
+	if value, ok := parseCount(filesPattern, line); ok {
+		s.Files = value
+	}
+	if value, ok := parseCount(bytesPattern, line); ok {
+		s.Bytes = value
+	}
+	if value, ok := parseCount(deletedPattern, line); ok {
+		s.Deleted = value
+	}
+}
+
+func parseChange(line string) (Progress, bool) {
+	if !strings.HasPrefix(line, "CHANGE|") {
+		return Progress{}, false
+	}
+	fields := strings.SplitN(strings.TrimPrefix(line, "CHANGE|"), "|", 2)
+	if len(fields) != 2 || len(fields[0]) != 11 {
+		return Progress{}, false
+	}
+	return Progress{Change: fields[0], CurrentFile: fields[1]}, true
+}