Redirect sqlcmd errors to err stream

cmd/sqlcmd/main.go

@@ -4,6 +4,7 @@
 package main
 
 import (
+	"errors"
 	"fmt"
 	"os"
 
@@ -259,7 +260,7 @@ func run(vars *sqlcmd.Variables, args *SQLCmdArguments) (int, error) {
 		if args.ErrorsToStderr >= 0 {
 			s.PrintError = func(msg string, severity uint8) bool {
 				if severity >= stderrSeverity {
-					_, _ = os.Stderr.Write([]byte(msg + sqlcmd.SqlcmdEol))
+					s.WriteError(os.Stderr, errors.New(msg+sqlcmd.SqlcmdEol))
 					return true
 				}
 				return false
@@ -285,7 +286,7 @@ func run(vars *sqlcmd.Variables, args *SQLCmdArguments) (int, error) {
 	} else {
 		for f := range args.InputFile {
 			if err = s.IncludeFile(args.InputFile[f], true); err != nil {
-				_, _ = os.Stderr.Write([]byte(err.Error() + sqlcmd.SqlcmdEol))
+				s.WriteError(s.GetError(), err)
 				s.Exitcode = 1
 				break
 			}

pkg/sqlcmd/commands.go

@@ -116,12 +116,12 @@ func (c Commands) matchCommand(line string) (*Command, []string) {
 }
 
 func warnDisabled(s *Sqlcmd, args []string, line uint) error {
-	_, _ = s.GetError().Write([]byte(ErrCommandsDisabled.Error() + SqlcmdEol))
+	s.WriteError(s.GetError(), ErrCommandsDisabled)
 	return nil
 }
 
 func errorDisabled(s *Sqlcmd, args []string, line uint) error {
-	_, _ = s.GetError().Write([]byte(ErrCommandsDisabled.Error() + SqlcmdEol))
+	s.WriteError(s.GetError(), ErrCommandsDisabled)
 	s.Exitcode = 1
 	return ErrExitRequested
 }
@@ -433,7 +433,7 @@ func resolveArgumentVariables(s *Sqlcmd, arg []rune, failOnUnresolved bool) (str
 					if failOnUnresolved {
 						return "", UndefinedVariable(varName)
 					}
-					_, _ = s.GetError().Write([]byte(UndefinedVariable(varName).Error() + SqlcmdEol))
+					s.WriteError(s.GetError(), UndefinedVariable(varName))
 					if b != nil {
 						b.WriteString(string(arg[i : vl+1]))
 					}

pkg/sqlcmd/sqlcmd.go

@@ -136,7 +136,7 @@ func (s *Sqlcmd) Run(once bool, processAll bool) error {
 				args = make([]string, 0)
 				once = true
 			} else {
-				_, _ = s.GetOutput().Write([]byte(err.Error() + SqlcmdEol))
+				s.WriteError(s.GetOutput(), err)
 			}
 		}
 		if cmd != nil {
@@ -146,7 +146,7 @@ func (s *Sqlcmd) Run(once bool, processAll bool) error {
 				break
 			}
 			if err != nil {
-				_, _ = s.GetOutput().Write([]byte(err.Error() + SqlcmdEol))
+				s.WriteError(s.GetOutput(), err)
 				lastError = err
 			}
 		}
@@ -209,6 +209,19 @@ func (s *Sqlcmd) SetError(e io.WriteCloser) {
 	s.err = e
 }
 
+// WriteError writes the error on specified stream
+func (s *Sqlcmd) WriteError(stream io.Writer, err error) {
+	if strings.HasPrefix(err.Error(), ErrorPrefix) {
+		if s.GetError() != os.Stdout {
+			_, _ = s.GetError().Write([]byte(err.Error() + SqlcmdEol))
+		} else {
+			_, _ = os.Stderr.Write([]byte(err.Error() + SqlcmdEol))
+		}
+	} else {
+		_, _ = stream.Write([]byte(err.Error() + SqlcmdEol))
+	}
+}
+
 // ConnectDb opens a connection to the database with the given modifications to the connection
 // nopw == true means don't prompt for a password if the auth type requires it
 // if connect is nil, ConnectDb uses the current connection. If non-nil and the connection succeeds,
@@ -364,7 +377,7 @@ func setupCloseHandler(s *Sqlcmd) {
 	signal.Notify(c, os.Interrupt, syscall.SIGTERM)
 	go func() {
 		<-c
-		_, _ = s.GetOutput().Write([]byte(ErrCtrlC.Error() + SqlcmdEol))
+		s.WriteError(s.GetOutput(), ErrCtrlC)
 		os.Exit(0)
 	}()
 }

pkg/sqlcmd/sqlcmd_test.go

@@ -462,6 +462,44 @@ func TestQueryServerPropertyReturnsColumnName(t *testing.T) {
 	}
 }
 
+func TestSqlCmdOutputAndError(t *testing.T) {
+	s, outfile, errfile := setupSqlcmdWithFileErrorOutput(t)
+	defer os.Remove(outfile.Name())
+	defer os.Remove(errfile.Name())
+	s.Query = "select $(X"
+	err := s.Run(true, false)
+	if assert.NoError(t, err, "s.Run(once = true)") {
+		bytes, err := os.ReadFile(errfile.Name())
+		if assert.NoError(t, err, "os.ReadFile") {
+			assert.Equal(t, "Sqlcmd: Error: Syntax error at line 1."+SqlcmdEol, string(bytes), "Expected syntax error not received for query execution")
+		}
+	}
+	s.Query = "select '1'"
+	err = s.Run(true, false)
+	if assert.NoError(t, err, "s.Run(once = true)") {
+		bytes, err := os.ReadFile(outfile.Name())
+		if assert.NoError(t, err, "os.ReadFile") {
+			assert.Equal(t, "1"+SqlcmdEol+SqlcmdEol+"(1 row affected)"+SqlcmdEol, string(bytes), "Unexpected output for query execution")
+		}
+	}
+
+	s, outfile, errfile = setupSqlcmdWithFileErrorOutput(t)
+	defer os.Remove(outfile.Name())
+	defer os.Remove(errfile.Name())
+	dataPath := "testdata" + string(os.PathSeparator)
+	err = s.IncludeFile(dataPath+"testerrorredirection.sql", false)
+	if assert.NoError(t, err, "IncludeFile testerrorredirection.sql false") {
+		bytes, err := os.ReadFile(outfile.Name())
+		if assert.NoError(t, err, "os.ReadFile outfile") {
+			assert.Equal(t, "1"+SqlcmdEol+SqlcmdEol+"(1 row affected)"+SqlcmdEol, string(bytes), "Unexpected output for sql file execution in outfile")
+		}
+		bytes, err = os.ReadFile(errfile.Name())
+		if assert.NoError(t, err, "os.ReadFile errfile") {
+			assert.Equal(t, "Sqlcmd: Error: Syntax error at line 3."+SqlcmdEol, string(bytes), "Expected syntax error not found in errfile")
+		}
+	}
+}
+
 // runSqlCmd uses lines as input for sqlcmd instead of relying on file or console input
 func runSqlCmd(t testing.TB, s *Sqlcmd, lines []string) error {
 	t.Helper()
@@ -509,6 +547,28 @@ func setupSqlcmdWithFileOutput(t testing.TB) (*Sqlcmd, *os.File) {
 	return s, file
 }
 
+func setupSqlcmdWithFileErrorOutput(t testing.TB) (*Sqlcmd, *os.File, *os.File) {
+	t.Helper()
+	v := InitializeVariables(true)
+	v.Set(SQLCMDMAXVARTYPEWIDTH, "0")
+	s := New(nil, "", v)
+	s.Connect = newConnect(t)
+	s.Format = NewSQLCmdDefaultFormatter(true)
+	outfile, err := os.CreateTemp("", "sqlcmdout")
+	assert.NoError(t, err, "os.CreateTemp")
+	errfile, err := os.CreateTemp("", "sqlcmderr")
+	assert.NoError(t, err, "os.CreateTemp")
+	s.SetOutput(outfile)
+	s.SetError(errfile)
+	err = s.ConnectDb(nil, true)
+	if err != nil {
+		os.Remove(outfile.Name())
+		os.Remove(errfile.Name())
+	}
+	assert.NoError(t, err, "s.ConnectDB")
+	return s, outfile, errfile
+}
+
 // Assuming public Azure, use AAD when SQLCMDUSER environment variable is not set
 func canTestAzureAuth() bool {
 	server := os.Getenv(SQLCMDSERVER)

pkg/sqlcmd/testdata/testerrorredirection.sql

@@ -0,0 +1,4 @@
+select '1'
+go
+select $(var
+go