fix: correct SentryStreamHandler to log Error and Crit

The constants are actually defined in the reverse order of their
severity. The prior behavior would log everything _but_ log.LvlCrit.

go/batch-submitter/sentry_log.go

@@ -11,18 +11,22 @@ import (
 var jsonFmt = log.JSONFormat()
 
 // SentryStreamHandler creates a log.Handler that behaves similarly to
-// log.StreamHandler, however it writes any log levels greater than or equal to
-// LvlError to Sentry. In that case, the passed log.Record is encoded using JSON
-// rather than the default terminal output, so that it can be captured for
-// debugging in the Sentry dashboard.
+// log.StreamHandler, however it writes any log with severity greater than or
+// equal to log.LvlError to Sentry. In that case, the passed log.Record is
+// encoded using JSON rather than the default terminal output, so that it can be
+// captured for debugging in the Sentry dashboard.
 func SentryStreamHandler(wr io.Writer, fmtr log.Format) log.Handler {
 	h := log.FuncHandler(func(r *log.Record) error {
 		_, err := wr.Write(fmtr.Format(r))
-		// If this record is LvlError or higher, serialize the record
-		// using JSON and write it to Sentry. We also capture the error
-		// message separately so that it's easy to parse what the error
-		// is in the dashboard.
-		if r.Lvl >= log.LvlError {
+		// If this record's severity is log.LvlError or higher,
+		// serialize the record using JSON and write it to Sentry. We
+		// also capture the error message separately so that it's easy
+		// to parse what the error is in the dashboard.
+		//
+		// NOTE: The log.Lvl* constants are defined in reverse order of
+		// their severity, i.e. zero (log.LvlCrit) is the highest
+		// severity.
+		if r.Lvl <= log.LvlError {
 			sentry.WithScope(func(scope *sentry.Scope) {
 				scope.SetExtra("context", jsonFmt.Format(r))
 				sentry.CaptureException(errors.New(r.Msg))