fix: keep the Msg/Level/State header on errors sent to stderr with -r

pkg/sqlcmd/format.go

@@ -249,11 +249,7 @@ func (f *sqlCmdFormatterType) AddError(err error) {
 	switch e := (err).(type) {
 	case mssql.Error:
 		if print = f.vars.ErrorLevel() <= 0 || e.Class >= uint8(f.vars.ErrorLevel()); print {
-			if len(e.ProcName) > 0 {
-				b.WriteString(localizer.Sprintf("Msg %#v, Level %d, State %d, Server %s, Procedure %s, Line %#v%s", e.Number, e.Class, e.State, e.ServerName, e.ProcName, e.LineNo, SqlcmdEol))
-			} else {
-				b.WriteString(localizer.Sprintf("Msg %#v, Level %d, State %d, Server %s, Line %#v%s", e.Number, e.Class, e.State, e.ServerName, e.LineNo, SqlcmdEol))
-			}
+			b.WriteString(errorHeader(e))
 			if !f.rawErrors {
 				msg = strings.TrimPrefix(msg, "mssql: ")
 			}
@@ -266,6 +262,15 @@ func (f *sqlCmdFormatterType) AddError(err error) {
 	}
 }
 
+// errorHeader returns the "Msg N, Level N, State N, ..." line that precedes a
+// server error message.
+func errorHeader(e mssql.Error) string {
+	if len(e.ProcName) > 0 {
+		return localizer.Sprintf("Msg %#v, Level %d, State %d, Server %s, Procedure %s, Line %#v%s", e.Number, e.Class, e.State, e.ServerName, e.ProcName, e.LineNo, SqlcmdEol)
+	}
+	return localizer.Sprintf("Msg %#v, Level %d, State %d, Server %s, Line %#v%s", e.Number, e.Class, e.State, e.ServerName, e.LineNo, SqlcmdEol)
+}
+
 // XmlMode enables or disables XML mode
 func (f *sqlCmdFormatterType) XmlMode(enable bool) {
 	f.xml = enable

pkg/sqlcmd/sqlcmd.go

@@ -81,6 +81,7 @@ type Sqlcmd struct {
 	// Cmd provides the implementation of commands like :list and GO
 	Cmd Commands
 	// PrintError allows the host to redirect errors away from the default output. Returns false if the error is not redirected by the host.
+	// For server errors msg includes the "Msg N, Level N, State N, ..." header line, as the default output would show it.
 	PrintError func(msg string, severity uint8) bool
 	// UnicodeOutputFile is true when UTF16 file output is needed
 	UnicodeOutputFile bool
@@ -485,7 +486,7 @@ func (s *Sqlcmd) runQuery(query string) (int, error) {
 		case sqlexp.MsgError:
 			switch e := m.Error.(type) {
 			case mssql.Error:
-				if !s.PrintError(e.Message, e.Class) {
+				if !s.PrintError(errorHeader(e)+e.Message, e.Class) {
 					s.Format.AddError(m.Error)
 				}
 			}

pkg/sqlcmd/sqlcmd_test.go

@@ -505,6 +505,26 @@ func TestSqlCmdDefersToPrintError(t *testing.T) {
 	}
 }
 
+// A host that redirects errors (sqlcmd -r) must receive the same
+// "Msg N, Level N, State N, ..." header the default output shows.
+func TestPrintErrorIncludesErrorHeader(t *testing.T) {
+	s, buf := setupSqlCmdWithMemoryOutput(t)
+	defer buf.Close()
+	redirected := ""
+	s.PrintError = func(msg string, severity uint8) bool {
+		if severity > 10 {
+			redirected += msg
+			return true
+		}
+		return false
+	}
+	err := runSqlCmd(t, s, []string{"RAISERROR (N'Testing!' , 11, 1)", "GO"})
+	if assert.NoError(t, err, "runSqlCmd failed") {
+		assert.Regexp(t, "^Msg 50000, Level 11, State 1, Server .+, Line 1"+SqlcmdEol+"Testing!$", redirected)
+		assert.Empty(t, buf.buf.String(), "redirected errors should not reach the default output")
+	}
+}
+
 func TestSqlCmdMaintainsConnectionBetweenBatches(t *testing.T) {
 	s, buf := setupSqlCmdWithMemoryOutput(t)
 	defer buf.Close()