SMTP: Fixes, minimum implementation for testmode, test stub for testmode

api_testsuite.go

@@ -17,6 +17,7 @@ import (
 	"github.com/sirupsen/logrus"
 
 	"github.com/programmfabrik/apitest/internal/httpproxy"
+	"github.com/programmfabrik/apitest/internal/smtp"
 	"github.com/programmfabrik/apitest/pkg/lib/datastore"
 	"github.com/programmfabrik/apitest/pkg/lib/filesystem"
 	"github.com/programmfabrik/apitest/pkg/lib/report"
@@ -36,7 +37,7 @@ type Suite struct {
 	} `json:"http_server,omitempty"`
 	SmtpServer *struct {
 		Addr string `json:"addr"`
-	}
+	} `json:"smtp_server,omitempty"`
 	Tests []any          `json:"tests"`
 	Store map[string]any `json:"store"`
 
@@ -57,7 +58,7 @@ type Suite struct {
 	idleConnsClosed chan struct{}
 	HTTPServerHost  string
 	loader          template.Loader
-	smtpServer      *SmtpServer
+	smtpServer      *smtp.Server
 }
 
 // NewTestSuite creates a new suite on which we execute our tests on. Normally this only gets call from within the apitest main command

internal/smtp/message.go

@@ -10,6 +10,19 @@ type ReceivedMessage struct {
 	receivedAt     time.Time
 }
 
-// TODO: Constructor that takes in from, rcptTo, rawMessageData, receivedAt and that also parses the message
+func NewReceivedMessage(
+	from string, rcptTo []string, rawMessageData []byte, receivedAt time.Time,
+) (*ReceivedMessage, error) {
+	msg := &ReceivedMessage{
+		smtpFrom:       from,
+		smtpRcptTo:     rcptTo,
+		rawMessageData: rawMessageData,
+		receivedAt:     receivedAt,
+	}
+
+	// TODO: Parse message
+
+	return msg, nil
+}
 
 // TODO: Getters

internal/smtp/server.go

@@ -1,11 +1,15 @@
 package smtp
 
 import (
+	"context"
 	"fmt"
+	"io"
 	"regexp"
 	"sync"
+	"time"
 
 	"github.com/emersion/go-smtp"
+	"github.com/sirupsen/logrus"
 )
 
 // Server contains a basic SMTP server for testing purposes.
@@ -14,27 +18,33 @@ import (
 // received messages, which can be queried using the appropriate methods
 // of Server.
 type Server struct {
-	server           smtp.Server
+	server           *smtp.Server
 	receivedMessages []*ReceivedMessage
 
 	mutex sync.RWMutex
 }
 
 type session struct {
-	// TODO
+	server *Server
+	conn   *smtp.Conn
+
+	from   string
+	rcptTo []string
 }
 
 func NewServer(addr string) *Server {
-	server := &Server{
-		receivedMessages: make([]receivedMessage),
-	}
+	server := new(Server)
 
-	backend := panic("not implemented") // TODO
+	backend := smtp.BackendFunc(func(c *smtp.Conn) (smtp.Session, error) {
+		return newSession(server, c)
+	})
 
-	server.server = smtp.NewServer(backend)
-	server.Addr = addr
-	// TODO: Enable SMTPUTF8?
-	// TODO: Enable BINARYMIME?
+	s := smtp.NewServer(backend)
+	s.Addr = addr
+	s.EnableSMTPUTF8 = true
+	s.EnableBINARYMIME = true
+
+	server.server = s
 
 	return server
 }
@@ -47,8 +57,8 @@ func (s *Server) ListenAndServe() error {
 
 // Shutdown shuts down the SMTP server that was previously started using
 // ListenAndServe.
-func (s *Server) Shutdown() error {
-	return s.server.Shutdown()
+func (s *Server) Shutdown(ctx context.Context) error {
+	return s.server.Shutdown(ctx)
 }
 
 // ReceivedMessage returns a message that the server has retrieved
@@ -57,25 +67,24 @@ func (s *Server) ReceivedMessage(idx int) (*ReceivedMessage, error) {
 	s.mutex.RLock()
 	defer s.mutex.RUnlock()
 
-	msg, ok := s.receivedMessages[idx]
-	if !ok {
+	if idx >= len(s.receivedMessages) {
 		return nil, fmt.Errorf(
 			"Server does not contain message with index %d", idx,
 		)
 	}
 
-	return msg, nil
+	return s.receivedMessages[idx], nil
 }
 
 // ReceivedMessages returns the list of all messages that the server has
 // retrieved.
-func (s *Server) ReceivedMessages() []ReceivedMessage {
+func (s *Server) ReceivedMessages() []*ReceivedMessage {
 	s.mutex.RLock()
 	defer s.mutex.RUnlock()
 
 	// We copy the slice to avoid race conditions when the receivedMessages slice is updated.
 	// It's just a slice of pointers, so it should be relatively lightweight.
-	view := make([]*ReceivedMessage, len(s.receivedMessage))
+	view := make([]*ReceivedMessage, len(s.receivedMessages))
 	copy(view, s.receivedMessages)
 
 	return view
@@ -90,3 +99,59 @@ func (s *Server) SearchByHeader(re *regexp.Regexp) []ReceivedMessage {
 	// TODO
 	panic("not implemented")
 }
+
+func newSession(server *Server, c *smtp.Conn) (smtp.Session, error) {
+	return &session{
+		server: server,
+		conn:   c,
+	}, nil
+}
+
+// Implements smtp.Session's Data method.
+func (s *session) Data(r io.Reader) error {
+	rawData, err := io.ReadAll(r)
+	if err != nil {
+		return fmt.Errorf("could not read mail data from SMTP: %w", err)
+	}
+
+	s.server.mutex.Lock()
+	defer s.server.mutex.Unlock()
+
+	now := time.Now()
+
+	logrus.Infof("SMTP: Received message from %s to %v at %v", s.from, s.rcptTo, now)
+	msg, err := NewReceivedMessage(s.from, s.rcptTo, rawData, now)
+	if err != nil {
+		return fmt.Errorf("error constructing ReceivedMessage in SMTP server: %w", err)
+	}
+
+	s.server.receivedMessages = append(s.server.receivedMessages, msg)
+
+	return nil
+}
+
+// Implements smtp.Session's Logout method.
+func (s *session) Logout() error {
+	s.Reset()
+	return nil
+}
+
+// Implements smtp.Session's Mail method.
+func (s *session) Mail(from string, opts *smtp.MailOptions) error {
+	// opts are currently ignored
+	s.from = from
+	return nil
+}
+
+// Implements smtp.Session's Rcpt method.
+func (s *session) Rcpt(to string, opts *smtp.RcptOptions) error {
+	// opts are currently ignored
+	s.rcptTo = append(s.rcptTo, to)
+	return nil
+}
+
+// Implements smtp.Session's Reset method.
+func (s *session) Reset() {
+	s.from = ""
+	s.rcptTo = nil
+}

smtp_server.go

@@ -1,6 +1,8 @@
 package main
 
 import (
+	"context"
+
 	esmtp "github.com/emersion/go-smtp"
 	"github.com/pkg/errors"
 	"github.com/sirupsen/logrus"
@@ -35,7 +37,8 @@ func (ats *Suite) StopSmtpServer() {
 		return
 	}
 
-	err := ats.smtpServer.Shutdown()
+	// TODO: Shouldn't this use a context with a timeout (also at http_server.go)?
+	err := ats.smtpServer.Shutdown(context.Background())
 	if err != nil {
 		// logrus.Error is used instead of Fatal, because an error
 		// during closing of a server shouldn't affect the outcome of

test/email/manifest.json

@@ -0,0 +1,10 @@
+{
+    "http_server": {
+        "addr": ":9999",
+        "testmode": true
+    },
+    "smtp_server": {
+        "addr": ":9925"
+    },
+    "name": "smtp server test mode"
+}