From b8f0462ce389820f2ef0c571208992ac685a2f6b Mon Sep 17 00:00:00 2001 From: Winni Neessen Date: Fri, 20 Sep 2024 15:49:03 +0200 Subject: [PATCH] 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. --- client_test.go | 374 +++++++++++++++++++++++++++++++++++++++++++++++-- 1 file changed, 365 insertions(+), 9 deletions(-) diff --git a/client_test.go b/client_test.go index c1706bf..d1e269a 100644 --- a/client_test.go +++ b/client_test.go @@ -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(), "") { + t.Errorf("expected message ID: %q, but got %q", "", + 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(), "") { + t.Errorf("expected message ID: %q, but got %q", "", + 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: ") { + t.Errorf("expected error: %q, but got %q", + "503 5.1.2 Invalid from: ", 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(), "") { + t.Errorf("expected message ID: %q, but got %q", "", + 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: ") { + t.Errorf("expected error: %q, but got %q", + "500 5.1.2 Invalid to: ", 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(), "") { + t.Errorf("expected message ID: %q, but got %q", "", + 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(), "") { + t.Errorf("expected message ID: %q, but got %q", "", + 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, "") { + if !strings.EqualFold(from, "") { _ = 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, "") { + to = strings.TrimSpace(to) + if !strings.EqualFold(to, "") { _ = 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