Fix Sentry Debug Message for empty command

internal/nomad/command_execution.go

@@ -182,7 +182,9 @@ func injectStartDebugMessage(command string, start uint, end int) string {
 	if strings.HasPrefix(description, "\"") && strings.HasSuffix(description, "\"") {
 		description = description[1 : len(description)-1]
 	}
-
+	if description == "" {
+		description = timeDebugFallbackDescription
+	}
 	description = dto.BashEscapeCommand(description)
 	description = description[1 : len(description)-1] // The most outer quotes are not escaped!
 	return fmt.Sprintf(timeDebugMessageFormatStart, description, command)

internal/nomad/sentry_debug_writer.go

@@ -23,6 +23,7 @@ var (
 	timeDebugMessagePattern = regexp.MustCompile(
 		`(?P<before>[\S\s]*?)\x1EPoseidon (?P<text>[^\x1E]+?) (?P<time>\d{13})\x1E(?P<after>[\S\s]*)`)
 	timeDebugMessagePatternStart = regexp.MustCompile(`\x1EPoseidon`)
+	timeDebugFallbackDescription = "<empty>"
 )
 
 // SentryDebugWriter is scanning the input for the debug message pattern.
@@ -68,7 +69,7 @@ func (s *SentryDebugWriter) Write(debugData []byte) (n int, err error) {
 
 	match := matchAndMapTimeDebugMessage(debugData)
 	if match == nil {
-		log.WithContext(s.lastSpan.Context()).WithField("data", debugData).Warn("Exec debug message could not be read completely")
+		log.WithContext(s.lastSpan.Context()).WithField("data", fmt.Sprintf("%q", debugData)).Warn("Exec debug message could not be read completely")
 		return 0, nil
 	}
 

internal/nomad/sentry_debug_writer_test.go

@@ -2,6 +2,7 @@ package nomad
 
 import (
 	"bytes"
+	"os/exec"
 )
 
 func (s *MainTestSuite) TestSentryDebugWriter_Write() {
@@ -29,6 +30,23 @@ func (s *MainTestSuite) TestSentryDebugWriter_WriteComposed() {
 	s.Contains(buf.String(), "Hello World!")
 }
 
+func (s *MainTestSuite) TestSentryDebugWriter_regression_593_empty_command() {
+	buf := &bytes.Buffer{}
+	debugWriter := NewSentryDebugWriter(s.TestCtx, buf)
+
+	const commandFieldAfterEnv = 4 // instead of "env CODEOCEAN=true /bin/bash -c sleep infinity" just "sleep infinity".
+	command := injectStartDebugMessage("env CODEOCEAN=true /bin/bash -c \"\"", commandFieldAfterEnv, -1)
+	cmd := exec.Command("/bin/bash", "-c", command)
+	stdout, err := cmd.Output()
+	s.Require().NoError(err)
+
+	count, err := debugWriter.Write(stdout)
+	s.Require().NoError(err)
+	s.NotEmpty(count)
+	s.Empty(buf.Bytes())
+	s.Equal(timeDebugFallbackDescription, debugWriter.lastSpan.Description)
+}
+
 func (s *MainTestSuite) TestSentryDebugWriter_regression_issue_678() {
 	buf := &bytes.Buffer{}
 	debugWriter := NewSentryDebugWriter(s.TestCtx, buf)