Add error handling tests for SMTP client

Implemented multiple tests to cover various error scenarios in the SMTP client, including invalid email addresses and data transmission failures. Introduced `failReset` flag in `simpleSMTPServer` to simulate server reset failures.
This commit is contained in:
Winni Neessen 2024-09-20 15:49:03 +02:00
parent 6af6a28f78
commit b8f0462ce3
Signed by: wneessen
GPG key ID: 385AC9889632126E

View file

@ -1265,7 +1265,7 @@ func TestClient_SendErrorNoEncoding(t *testing.T) {
featureSet := "250-AUTH PLAIN\r\n250-DSN\r\n250 SMTPUTF8"
go func() {
if err := simpleSMTPServer(ctx, featureSet); err != nil {
if err := simpleSMTPServer(ctx, featureSet, false); err != nil {
t.Errorf("failed to start test server: %s", err)
return
}
@ -1273,11 +1273,11 @@ func TestClient_SendErrorNoEncoding(t *testing.T) {
time.Sleep(time.Millisecond * 300) // wait until tcp server has been settled
message := NewMsg()
if err := message.From("invalid-from@domain.tld"); err != nil {
if err := message.From("valid-from@domain.tld"); err != nil {
t.Errorf("failed to set FROM address: %s", err)
return
}
if err := message.To("invalid-to@domain.tld"); err != nil {
if err := message.To("valid-to@domain.tld"); err != nil {
t.Errorf("failed to set TO address: %s", err)
return
}
@ -1325,6 +1325,344 @@ func TestClient_SendErrorNoEncoding(t *testing.T) {
}
}
func TestClient_SendErrorMailFrom(t *testing.T) {
ctx, cancel := context.WithCancel(context.Background())
defer cancel()
featureSet := "250-AUTH PLAIN\r\n250-8BITMIME\r\n250-DSN\r\n250 SMTPUTF8"
go func() {
if err := simpleSMTPServer(ctx, featureSet, false); err != nil {
t.Errorf("failed to start test server: %s", err)
return
}
}()
time.Sleep(time.Millisecond * 300) // wait until tcp server has been settled
message := NewMsg()
if err := message.From("invalid-from@domain.tld"); err != nil {
t.Errorf("failed to set FROM address: %s", err)
return
}
if err := message.To("valid-to@domain.tld"); err != nil {
t.Errorf("failed to set TO address: %s", err)
return
}
message.Subject("Test subject")
message.SetBodyString(TypeTextPlain, "Test body")
message.SetMessageIDWithValue("this.is.a.message.id")
client, err := NewClient(TestServerAddr, WithPort(TestServerPort),
WithTLSPortPolicy(NoTLS), WithSMTPAuth(SMTPAuthPlain),
WithUsername("toni@tester.com"),
WithPassword("V3ryS3cr3t+"))
if err != nil {
t.Errorf("unable to create new client: %s", err)
}
if err = client.DialWithContext(context.Background()); err != nil {
t.Errorf("failed to dial to test server: %s", err)
}
if err = client.Send(message); err == nil {
t.Error("expected Send() to fail but didn't")
}
var sendErr *SendError
if !errors.As(err, &sendErr) {
t.Errorf("expected *SendError type as returned error, but got %T", sendErr)
}
if errors.As(err, &sendErr) {
if sendErr.IsTemp() {
t.Errorf("expected permanent error but IsTemp() returned true")
}
if sendErr.Reason != ErrSMTPMailFrom {
t.Errorf("expected ErrSMTPMailFrom error, but got %s", sendErr.Reason)
}
if !strings.EqualFold(sendErr.MessageID(), "<this.is.a.message.id>") {
t.Errorf("expected message ID: %q, but got %q", "<this.is.a.message.id>",
sendErr.MessageID())
}
if sendErr.Msg() == nil {
t.Errorf("expected message to be set, but got nil")
}
}
if err = client.Close(); err != nil {
t.Errorf("failed to close server connection: %s", err)
}
}
func TestClient_SendErrorMailFromReset(t *testing.T) {
ctx, cancel := context.WithCancel(context.Background())
defer cancel()
featureSet := "250-AUTH PLAIN\r\n250-8BITMIME\r\n250-DSN\r\n250 SMTPUTF8"
go func() {
if err := simpleSMTPServer(ctx, featureSet, true); err != nil {
t.Errorf("failed to start test server: %s", err)
return
}
}()
time.Sleep(time.Millisecond * 300) // wait until tcp server has been settled
message := NewMsg()
if err := message.From("invalid-from@domain.tld"); err != nil {
t.Errorf("failed to set FROM address: %s", err)
return
}
if err := message.To("valid-to@domain.tld"); err != nil {
t.Errorf("failed to set TO address: %s", err)
return
}
message.Subject("Test subject")
message.SetBodyString(TypeTextPlain, "Test body")
message.SetMessageIDWithValue("this.is.a.message.id")
client, err := NewClient(TestServerAddr, WithPort(TestServerPort),
WithTLSPortPolicy(NoTLS), WithSMTPAuth(SMTPAuthPlain),
WithUsername("toni@tester.com"),
WithPassword("V3ryS3cr3t+"))
if err != nil {
t.Errorf("unable to create new client: %s", err)
}
if err = client.DialWithContext(context.Background()); err != nil {
t.Errorf("failed to dial to test server: %s", err)
}
if err = client.Send(message); err == nil {
t.Error("expected Send() to fail but didn't")
}
var sendErr *SendError
if !errors.As(err, &sendErr) {
t.Errorf("expected *SendError type as returned error, but got %T", sendErr)
}
if errors.As(err, &sendErr) {
if sendErr.IsTemp() {
t.Errorf("expected permanent error but IsTemp() returned true")
}
if sendErr.Reason != ErrSMTPMailFrom {
t.Errorf("expected ErrSMTPMailFrom error, but got %s", sendErr.Reason)
}
if !strings.EqualFold(sendErr.MessageID(), "<this.is.a.message.id>") {
t.Errorf("expected message ID: %q, but got %q", "<this.is.a.message.id>",
sendErr.MessageID())
}
if len(sendErr.errlist) != 2 {
t.Errorf("expected 2 errors, but got %d", len(sendErr.errlist))
return
}
if !strings.EqualFold(sendErr.errlist[0].Error(), "503 5.1.2 Invalid from: <invalid-from@domain.tld>") {
t.Errorf("expected error: %q, but got %q",
"503 5.1.2 Invalid from: <invalid-from@domain.tld>", sendErr.errlist[0].Error())
}
if !strings.EqualFold(sendErr.errlist[1].Error(), "500 5.1.2 Error: reset failed") {
t.Errorf("expected error: %q, but got %q",
"500 5.1.2 Error: reset failed", sendErr.errlist[1].Error())
}
}
if err = client.Close(); err != nil {
t.Errorf("failed to close server connection: %s", err)
}
}
func TestClient_SendErrorToReset(t *testing.T) {
ctx, cancel := context.WithCancel(context.Background())
defer cancel()
featureSet := "250-AUTH PLAIN\r\n250-8BITMIME\r\n250-DSN\r\n250 SMTPUTF8"
go func() {
if err := simpleSMTPServer(ctx, featureSet, true); err != nil {
t.Errorf("failed to start test server: %s", err)
return
}
}()
time.Sleep(time.Millisecond * 300) // wait until tcp server has been settled
message := NewMsg()
if err := message.From("valid-from@domain.tld"); err != nil {
t.Errorf("failed to set FROM address: %s", err)
return
}
if err := message.To("invalid-to@domain.tld"); err != nil {
t.Errorf("failed to set TO address: %s", err)
return
}
message.Subject("Test subject")
message.SetBodyString(TypeTextPlain, "Test body")
message.SetMessageIDWithValue("this.is.a.message.id")
client, err := NewClient(TestServerAddr, WithPort(TestServerPort),
WithTLSPortPolicy(NoTLS), WithSMTPAuth(SMTPAuthPlain),
WithUsername("toni@tester.com"),
WithPassword("V3ryS3cr3t+"))
if err != nil {
t.Errorf("unable to create new client: %s", err)
}
if err = client.DialWithContext(context.Background()); err != nil {
t.Errorf("failed to dial to test server: %s", err)
}
if err = client.Send(message); err == nil {
t.Error("expected Send() to fail but didn't")
}
var sendErr *SendError
if !errors.As(err, &sendErr) {
t.Errorf("expected *SendError type as returned error, but got %T", sendErr)
}
if errors.As(err, &sendErr) {
if sendErr.IsTemp() {
t.Errorf("expected permanent error but IsTemp() returned true")
}
if sendErr.Reason != ErrSMTPRcptTo {
t.Errorf("expected ErrSMTPRcptTo error, but got %s", sendErr.Reason)
}
if !strings.EqualFold(sendErr.MessageID(), "<this.is.a.message.id>") {
t.Errorf("expected message ID: %q, but got %q", "<this.is.a.message.id>",
sendErr.MessageID())
}
if len(sendErr.errlist) != 2 {
t.Errorf("expected 2 errors, but got %d", len(sendErr.errlist))
return
}
if !strings.EqualFold(sendErr.errlist[0].Error(), "500 5.1.2 Invalid to: <invalid-to@domain.tld>") {
t.Errorf("expected error: %q, but got %q",
"500 5.1.2 Invalid to: <invalid-to@domain.tld>", sendErr.errlist[0].Error())
}
if !strings.EqualFold(sendErr.errlist[1].Error(), "500 5.1.2 Error: reset failed") {
t.Errorf("expected error: %q, but got %q",
"500 5.1.2 Error: reset failed", sendErr.errlist[1].Error())
}
}
if err = client.Close(); err != nil {
t.Errorf("failed to close server connection: %s", err)
}
}
func TestClient_SendErrorDataClose(t *testing.T) {
ctx, cancel := context.WithCancel(context.Background())
defer cancel()
featureSet := "250-AUTH PLAIN\r\n250-8BITMIME\r\n250-DSN\r\n250 SMTPUTF8"
go func() {
if err := simpleSMTPServer(ctx, featureSet, false); err != nil {
t.Errorf("failed to start test server: %s", err)
return
}
}()
time.Sleep(time.Millisecond * 300)
message := NewMsg()
if err := message.From("valid-from@domain.tld"); err != nil {
t.Errorf("failed to set FROM address: %s", err)
return
}
if err := message.To("valid-to@domain.tld"); err != nil {
t.Errorf("failed to set TO address: %s", err)
return
}
message.Subject("Test subject")
message.SetBodyString(TypeTextPlain, "DATA close should fail")
message.SetMessageIDWithValue("this.is.a.message.id")
client, err := NewClient(TestServerAddr, WithPort(TestServerPort),
WithTLSPortPolicy(NoTLS), WithSMTPAuth(SMTPAuthPlain),
WithUsername("toni@tester.com"),
WithPassword("V3ryS3cr3t+"))
if err != nil {
t.Errorf("unable to create new client: %s", err)
}
if err = client.DialWithContext(context.Background()); err != nil {
t.Errorf("failed to dial to test server: %s", err)
}
if err = client.Send(message); err == nil {
t.Error("expected Send() to fail but didn't")
}
var sendErr *SendError
if !errors.As(err, &sendErr) {
t.Errorf("expected *SendError type as returned error, but got %T", sendErr)
}
if errors.As(err, &sendErr) {
if sendErr.IsTemp() {
t.Errorf("expected permanent error but IsTemp() returned true")
}
if sendErr.Reason != ErrSMTPDataClose {
t.Errorf("expected ErrSMTPDataClose error, but got %s", sendErr.Reason)
}
if !strings.EqualFold(sendErr.MessageID(), "<this.is.a.message.id>") {
t.Errorf("expected message ID: %q, but got %q", "<this.is.a.message.id>",
sendErr.MessageID())
}
}
if err = client.Close(); err != nil {
t.Errorf("failed to close server connection: %s", err)
}
}
func TestClient_SendErrorDataWrite(t *testing.T) {
ctx, cancel := context.WithCancel(context.Background())
defer cancel()
featureSet := "250-AUTH PLAIN\r\n250-8BITMIME\r\n250-DSN\r\n250 SMTPUTF8"
go func() {
if err := simpleSMTPServer(ctx, featureSet, false); err != nil {
t.Errorf("failed to start test server: %s", err)
return
}
}()
time.Sleep(time.Millisecond * 300)
message := NewMsg()
if err := message.From("valid-from@domain.tld"); err != nil {
t.Errorf("failed to set FROM address: %s", err)
return
}
if err := message.To("valid-to@domain.tld"); err != nil {
t.Errorf("failed to set TO address: %s", err)
return
}
message.Subject("Test subject")
message.SetBodyString(TypeTextPlain, "DATA write should fail")
message.SetMessageIDWithValue("this.is.a.message.id")
message.SetGenHeader("X-Test-Header", "DATA write should fail")
client, err := NewClient(TestServerAddr, WithPort(TestServerPort),
WithTLSPortPolicy(NoTLS), WithSMTPAuth(SMTPAuthPlain),
WithUsername("toni@tester.com"),
WithPassword("V3ryS3cr3t+"))
if err != nil {
t.Errorf("unable to create new client: %s", err)
}
if err = client.DialWithContext(context.Background()); err != nil {
t.Errorf("failed to dial to test server: %s", err)
}
if err = client.Send(message); err == nil {
t.Error("expected Send() to fail but didn't")
}
var sendErr *SendError
if !errors.As(err, &sendErr) {
t.Errorf("expected *SendError type as returned error, but got %T", sendErr)
}
if errors.As(err, &sendErr) {
if sendErr.IsTemp() {
t.Errorf("expected permanent error but IsTemp() returned true")
}
if sendErr.Reason != ErrSMTPDataClose {
t.Errorf("expected ErrSMTPDataClose error, but got %s", sendErr.Reason)
}
if !strings.EqualFold(sendErr.MessageID(), "<this.is.a.message.id>") {
t.Errorf("expected message ID: %q, but got %q", "<this.is.a.message.id>",
sendErr.MessageID())
}
}
if err = client.Close(); err != nil {
t.Errorf("failed to close server connection: %s", err)
}
}
// getTestConnection takes environment variables to establish a connection to a real
// SMTP server to test all functionality that requires a connection
func getTestConnection(auth bool) (*Client, error) {
@ -1620,7 +1958,10 @@ func (f faker) SetDeadline(time.Time) error { return nil }
func (f faker) SetReadDeadline(time.Time) error { return nil }
func (f faker) SetWriteDeadline(time.Time) error { return nil }
func simpleSMTPServer(ctx context.Context, featureSet string) error {
// simpleSMTPServer starts a simple TCP server that resonds to SMTP commands.
// The provided featureSet represents in what the server responds to EHLO command
// failReset controls if a RSET succeeds
func simpleSMTPServer(ctx context.Context, featureSet string, failReset bool) error {
listener, err := net.Listen(TestServerProto, fmt.Sprintf("%s:%d", TestServerAddr, TestServerPort))
if err != nil {
return fmt.Errorf("unable to listen on %s://%s: %w", TestServerProto, TestServerAddr, err)
@ -1646,12 +1987,12 @@ func simpleSMTPServer(ctx context.Context, featureSet string) error {
}
return fmt.Errorf("unable to accept connection: %w", err)
}
handleTestServerConnection(connection, featureSet)
handleTestServerConnection(connection, featureSet, failReset)
}
}
}
func handleTestServerConnection(connection net.Conn, featureSet string) {
func handleTestServerConnection(connection net.Conn, featureSet string, failReset bool) {
defer func() {
if err := connection.Close(); err != nil {
fmt.Printf("unable to close connection: %s\n", err)
@ -1709,14 +2050,15 @@ func handleTestServerConnection(connection net.Conn, featureSet string) {
from = strings.ReplaceAll(from, "BODY=8BITMIME", "")
from = strings.ReplaceAll(from, "SMTPUTF8", "")
from = strings.TrimSpace(from)
if !strings.EqualFold(from, "<invalid-from@domain.tld>") {
if !strings.EqualFold(from, "<valid-from@domain.tld>") {
_ = writeLine(fmt.Sprintf("503 5.1.2 Invalid from: %s", from))
break
}
writeOK()
case strings.HasPrefix(data, "RCPT TO:"):
to := strings.TrimPrefix(data, "RCPT TO:")
if !strings.EqualFold(to, "<invalid-to@domain.tld>") {
to = strings.TrimSpace(to)
if !strings.EqualFold(to, "<valid-to@domain.tld>") {
_ = writeLine(fmt.Sprintf("500 5.1.2 Invalid to: %s", to))
break
}
@ -1737,17 +2079,31 @@ func handleTestServerConnection(connection net.Conn, featureSet string) {
break
}
ddata = strings.TrimSpace(ddata)
if strings.EqualFold(ddata, "DATA write should fail") {
_ = writeLine("500 5.0.0 Error during DATA transmission")
break
}
if ddata == "." {
if strings.Contains(datastring, "DATA close should fail") {
_ = writeLine("500 5.0.0 Error during DATA closing")
break
}
_ = writeLine("250 2.0.0 Ok: queued as 1234567890")
break
}
datastring += ddata + "\n"
}
case strings.EqualFold(data, "noop"),
strings.EqualFold(data, "rset"),
strings.EqualFold(data, "vrfy"):
writeOK()
break
case strings.EqualFold(data, "rset"):
if failReset {
_ = writeLine("500 5.1.2 Error: reset failed")
break
}
writeOK()
break
case strings.EqualFold(data, "quit"):
_ = writeLine("221 2.0.0 Bye")
break