emailsender/pkg/email/email_test.go

package email

import (
	"bytes"
	"context"
	"errors"
	"strings"
	"testing"
)

func TestMockSendEmailCompatibility(t *testing.T) {
	t.Parallel()
	called := false
	service := NewMockMailService(func(params ...interface{}) {
		called = true
		if len(params) != 1 || params[0] != "marker" {
			t.Fatalf("unexpected callback params: %#v", params)
		}
	}, "marker")

	err := service.SendEmail(MessageWithAttachments{
		To:      "test@example.com",
		Subject: "Test Email",
		Body:    "This is a test email.",
	})
	if err != nil {
		t.Fatalf("SendEmail: %v", err)
	}
	if !called {
		t.Fatal("mock callback was not invoked")
	}
}

func TestStructuredMessageRejectsHeaderInjection(t *testing.T) {
	t.Parallel()
	service := NewMockMailService(nil)
	tests := []MessageWithAttachments{
		{To: "victim@example.com", Subject: "subject\r\nBcc: attacker@example.com", Body: "body"},
		{To: "victim@example.com\r\nBcc: attacker@example.com", Subject: "subject", Body: "body"},
		{
			To:      "victim@example.com",
			Subject: "subject",
			Body:    "body",
			Attachments: []EmailAttachment{{
				Title: "file.txt\r\nX-Injected: yes",
				File:  bytes.NewBufferString("content"),
			}},
		},
	}
	for index, message := range tests {
		if err := service.SendEmailContext(context.Background(), message); err == nil {
			t.Fatalf("case %d accepted injected header", index)
		}
	}
}

func TestLegacyConstructorReturnsSafeConfigurationError(t *testing.T) {
	t.Parallel()
	service := NewSecure(SecureConfig{Host: "", Port: "587", From: "sender@example.com"})
	err := service.SendRaw(RawMessage{To: "recipient@example.com", Body: "Subject: x\r\n\r\nbody"})
	var transportError *Error
	if !errors.As(err, &transportError) || transportError.Kind != ErrorKindPermanent {
		t.Fatalf("error=%v, want permanent configuration error", err)
	}
	if strings.Contains(err.Error(), "recipient@example.com") {
		t.Fatalf("configuration error leaked message data: %v", err)
	}
}