make Mailer an interface

auth/pwdless/api.go

@@ -33,21 +33,16 @@ type AuthStorer interface {
 	PurgeExpiredToken() error
 }
 
-// Mailer defines methods to send account emails.
-type Mailer interface {
-	LoginToken(name, email string, c email.ContentLoginToken) error
-}
-
 // Resource implements passwordless account authentication against a database.
 type Resource struct {
 	LoginAuth *LoginTokenAuth
 	TokenAuth *jwt.TokenAuth
 	Store     AuthStorer
-	Mailer    Mailer
+	Mailer    email.Mailer
 }
 
 // NewResource returns a configured authentication resource.
-func NewResource(authStore AuthStorer, mailer Mailer) (*Resource, error) {
+func NewResource(authStore AuthStorer, mailer email.Mailer) (*Resource, error) {
 	loginAuth, err := NewLoginTokenAuth()
 	if err != nil {
 		return nil, err
@@ -126,14 +121,17 @@ func (rs *Resource) login(w http.ResponseWriter, r *http.Request) {
 	tokenURL, _ := url.JoinPath(rs.LoginAuth.loginURL, lt.Token)
 
 	go func() {
-		content := email.ContentLoginToken{
+		content := ContentLoginToken{
 			Email:  acc.Email,
 			Name:   acc.Name,
 			URL:    tokenURL,
 			Token:  lt.Token,
 			Expiry: lt.Expiry,
 		}
-		if err := rs.Mailer.LoginToken(acc.Name, acc.Email, content); err != nil {
+
+		msg := LoginTokenEmail(acc.Name, acc.Email, content)
+
+		if err := rs.Mailer.Send(msg); err != nil {
 			log(r).WithField("module", "email").Error(err)
 		}
 	}()

auth/pwdless/api_test.go

@@ -24,7 +24,7 @@ import (
 var (
 	auth      *Resource
 	authStore MockAuthStore
-	mailer    email.MockMailer
+	mailer    *email.MockMailer
 	ts        *httptest.Server
 )
 
@@ -35,7 +35,9 @@ func TestMain(m *testing.M) {
 	viper.SetDefault("log_level", "error")
 
 	var err error
-	auth, err = NewResource(&authStore, &mailer)
+
+	mailer = email.NewMockMailer()
+	auth, err = NewResource(&authStore, mailer)
 	if err != nil {
 		fmt.Println(err)
 		os.Exit(1)
@@ -72,10 +74,6 @@ func TestAuthResource_login(t *testing.T) {
 		return &a, err
 	}
 
-	mailer.LoginTokenFn = func(n, e string, c email.ContentLoginToken) error {
-		return nil
-	}
-
 	tests := []struct {
 		name   string
 		email  string
@@ -105,11 +103,11 @@ func TestAuthResource_login(t *testing.T) {
 			if tc.err == ErrInvalidLogin && authStore.GetAccountByEmailInvoked {
 				t.Error("GetByLoginToken invoked for invalid email")
 			}
-			if tc.err == nil && !mailer.LoginTokenInvoked {
-				t.Error("emailService.LoginToken not invoked")
+			if tc.err == nil && !mailer.SendInvoked {
+				t.Error("emailService.Send not invoked")
 			}
 			authStore.GetAccountByEmailInvoked = false
-			mailer.LoginTokenInvoked = false
+			mailer.SendInvoked = false
 		})
 	}
 }

auth/pwdless/emails.go

@@ -0,0 +1,28 @@
+package pwdless
+
+import (
+	"os"
+	"time"
+
+	"github.com/dhax/go-base/email"
+)
+
+// ContentLoginToken defines content for login token email template.
+type ContentLoginToken struct {
+	Email  string
+	Name   string
+	URL    string
+	Token  string
+	Expiry time.Time
+}
+
+// LoginTokenEmail creates and sends a login token email with provided template content.
+func LoginTokenEmail(name, address string, content ContentLoginToken) email.Message {
+	return email.Message{
+		From:     email.NewEmail(os.Getenv("EMAIL_FROM_NAME"), os.Getenv("EMAIL_FROM_ADDRESS")),
+		To:       email.NewEmail(name, address),
+		Subject:  "Login Token",
+		Template: "loginToken",
+		Content:  content,
+	}
+}

auth/pwdless/logintoken.go

@@ -9,9 +9,7 @@ import (
 	"github.com/spf13/viper"
 )
 
-var (
-	errTokenNotFound = errors.New("login token not found")
-)
+var errTokenNotFound = errors.New("login token not found")
 
 // LoginToken is an in-memory saved token referencing an account ID and an expiry date.
 type LoginToken struct {

docker-compose.yml

@@ -14,7 +14,7 @@ services:
       #AUTH_JWT_EXPIRY: 1h
       #AUTH_JWT_REFRESH_EXPIRY: 72h
       #AUTH_JWT_SECRET: my secret
-      #EMAIL_FROM_ADDRESS: go-base
+      #EMAIL_FROM_ADDRESS: go-base@example.com
       #EMAIL_FROM_NAME: Go Base
       #EMAIL_SMTP_HOST:
       #EMAIL_SMTP_PORT: 465

email/auth.go

@@ -1,29 +0,0 @@
-package email
-
-import "time"
-
-// ContentLoginToken defines content for login token email template.
-type ContentLoginToken struct {
-	Email  string
-	Name   string
-	URL    string
-	Token  string
-	Expiry time.Time
-}
-
-// LoginToken creates and sends a login token email with provided template content.
-func (m *Mailer) LoginToken(name, address string, content ContentLoginToken) error {
-	msg := &message{
-		from:     m.from,
-		to:       NewEmail(name, address),
-		subject:  "Login Token",
-		template: "loginToken",
-		content:  content,
-	}
-
-	if err := msg.parse(); err != nil {
-		return err
-	}
-
-	return m.Send(msg)
-}

email/email.go

@@ -1,170 +0,0 @@
-// Package email provides email sending functionality.
-package email
-
-import (
-	"bytes"
-	"fmt"
-	"html/template"
-	"log"
-	"os"
-	"path/filepath"
-	"strconv"
-	"strings"
-	"time"
-
-	"github.com/go-mail/mail"
-	"github.com/jaytaylor/html2text"
-	"github.com/spf13/viper"
-	"github.com/vanng822/go-premailer/premailer"
-)
-
-var (
-	debug     bool
-	templates *template.Template
-)
-
-// Mailer is a SMTP mailer.
-type Mailer struct {
-	client *mail.Dialer
-	from   Email
-}
-
-// NewMailer returns a configured SMTP Mailer.
-func NewMailer() (*Mailer, error) {
-	if err := parseTemplates(); err != nil {
-		return nil, err
-	}
-
-	smtp := struct {
-		Host     string
-		Port     int
-		User     string
-		Password string
-	}{
-		viper.GetString("email_smtp_host"),
-		viper.GetInt("email_smtp_port"),
-		viper.GetString("email_smtp_user"),
-		viper.GetString("email_smtp_password"),
-	}
-
-	s := &Mailer{
-		client: mail.NewDialer(smtp.Host, smtp.Port, smtp.User, smtp.Password),
-		from:   NewEmail(viper.GetString("email_from_name"), viper.GetString("email_from_address")),
-	}
-
-	if smtp.Host == "" {
-		log.Println("SMTP host not set => printing emails to stdout")
-		debug = true
-		return s, nil
-	}
-
-	d, err := s.client.Dial()
-	if err == nil {
-		d.Close()
-		return s, nil
-	}
-	return nil, err
-}
-
-// Send sends the mail via smtp.
-func (m *Mailer) Send(email *message) error {
-	if debug {
-		log.Println("To:", email.to.Address)
-		log.Println("Subject:", email.subject)
-		log.Println(email.text)
-		return nil
-	}
-
-	msg := mail.NewMessage()
-	msg.SetAddressHeader("From", email.from.Address, email.from.Name)
-	msg.SetAddressHeader("To", email.to.Address, email.to.Name)
-	msg.SetHeader("Subject", email.subject)
-	msg.SetBody("text/plain", email.text)
-	msg.AddAlternative("text/html", email.html)
-
-	return m.client.DialAndSend(msg)
-}
-
-// message struct holds all parts of a specific email message.
-type message struct {
-	from     Email
-	to       Email
-	subject  string
-	template string
-	content  interface{}
-	html     string
-	text     string
-}
-
-// parse parses the corrsponding template and content
-func (m *message) parse() error {
-	buf := new(bytes.Buffer)
-	if err := templates.ExecuteTemplate(buf, m.template, m.content); err != nil {
-		return err
-	}
-	prem, err := premailer.NewPremailerFromString(buf.String(), premailer.NewOptions())
-	if err != nil {
-		return err
-	}
-
-	html, err := prem.Transform()
-	if err != nil {
-		return err
-	}
-	m.html = html
-
-	text, err := html2text.FromString(html, html2text.Options{PrettyTables: true})
-	if err != nil {
-		return err
-	}
-	m.text = text
-	return nil
-}
-
-// Email struct holds email address and recipient name.
-type Email struct {
-	Name    string
-	Address string
-}
-
-// NewEmail returns an email address.
-func NewEmail(name string, address string) Email {
-	return Email{
-		Name:    name,
-		Address: address,
-	}
-}
-
-func parseTemplates() error {
-	templates = template.New("").Funcs(fMap)
-	return filepath.Walk("./templates", func(path string, info os.FileInfo, err error) error {
-		if strings.Contains(path, ".html") {
-			_, err = templates.ParseFiles(path)
-			return err
-		}
-		return err
-	})
-}
-
-var fMap = template.FuncMap{
-	"formatAsDate":     formatAsDate,
-	"formatAsDuration": formatAsDuration,
-}
-
-func formatAsDate(t time.Time) string {
-	year, month, day := t.Date()
-	return fmt.Sprintf("%d.%d.%d", day, month, year)
-}
-
-func formatAsDuration(t time.Time) string {
-	dur := time.Until(t)
-	hours := int(dur.Hours())
-	mins := int(dur.Minutes())
-
-	v := ""
-	if hours != 0 {
-		v += strconv.Itoa(hours) + " hours and "
-	}
-	v += strconv.Itoa(mins) + " minutes"
-	return v
-}

email/mailer.go

@@ -0,0 +1,106 @@
+// Package email provides email sending functionality.
+package email
+
+import (
+	"bytes"
+	"fmt"
+	"html/template"
+	"os"
+	"path/filepath"
+	"strconv"
+	"strings"
+	"time"
+
+	"github.com/jaytaylor/html2text"
+	"github.com/vanng822/go-premailer/premailer"
+)
+
+var templates *template.Template
+
+type Mailer interface {
+	Send(Message) error
+}
+
+// Message struct holds all parts of a specific email Message.
+type Message struct {
+	From     Email
+	To       Email
+	Subject  string
+	Template string
+	Content  any
+	html     string
+	text     string
+}
+
+// parse parses the corrsponding template and content
+func (m *Message) parse() error {
+	buf := new(bytes.Buffer)
+	if err := templates.ExecuteTemplate(buf, m.Template, m.Content); err != nil {
+		return err
+	}
+	prem, err := premailer.NewPremailerFromString(buf.String(), premailer.NewOptions())
+	if err != nil {
+		return err
+	}
+
+	html, err := prem.Transform()
+	if err != nil {
+		return err
+	}
+	m.html = html
+
+	text, err := html2text.FromString(html, html2text.Options{PrettyTables: true})
+	if err != nil {
+		return err
+	}
+	m.text = text
+	return nil
+}
+
+// Email struct holds email address and recipient name.
+type Email struct {
+	Name    string
+	Address string
+}
+
+// NewEmail returns an email address.
+func NewEmail(name string, address string) Email {
+	return Email{
+		Name:    name,
+		Address: address,
+	}
+}
+
+func parseTemplates() error {
+	templates = template.New("").Funcs(fMap)
+	return filepath.Walk("./templates", func(path string, info os.FileInfo, err error) error {
+		if strings.Contains(path, ".html") {
+			_, err = templates.ParseFiles(path)
+			return err
+		}
+		return err
+	})
+}
+
+var fMap = template.FuncMap{
+	"formatAsDate":     formatAsDate,
+	"formatAsDuration": formatAsDuration,
+}
+
+func formatAsDate(t time.Time) string {
+	year, month, day := t.Date()
+	return fmt.Sprintf("%d.%d.%d", day, month, year)
+}
+
+func formatAsDuration(t time.Time) string {
+	dur := time.Until(t)
+	hours := int(dur.Hours())
+	mins := int(dur.Minutes())
+
+	v := ""
+	if hours != 0 {
+		v += strconv.Itoa(hours) + " hours and "
+	}
+	v += strconv.Itoa(mins) + " minutes"
+	return v
+}

email/mockMailer.go

@@ -1,13 +1,28 @@
 package email
 
+import "log"
+
 // MockMailer is a mock Mailer
 type MockMailer struct {
-	LoginTokenFn      func(name, email string, c ContentLoginToken) error
-	LoginTokenInvoked bool
+	SendFn      func(m Message) error
+	SendInvoked bool
 }
 
-// LoginToken is a mock for LoginToken
-func (s *MockMailer) LoginToken(n, e string, c ContentLoginToken) error {
-	s.LoginTokenInvoked = true
-	return s.LoginTokenFn(n, e, c)
+func logMessage(m Message) {
+	log.Printf("MockMailer email sent:\nSubject: %s\nTo: %s <%s>\nContext: %#v\n", m.Subject, m.To.Name, m.To.Address, m.Content)
+}
+
+func NewMockMailer() *MockMailer {
+	log.Println("ATTENTION: SMTP Mailer not configured => printing emails to stdout")
+	return &MockMailer{
+		SendFn: func(m Message) error {
+			logMessage(m)
+			return nil
+		},
+	}
+}
+
+func (s *MockMailer) Send(m Message) error {
+	s.SendInvoked = true
+	return s.SendFn(m)
 }

email/smtp.go

@@ -0,0 +1,63 @@
+package email
+
+import (
+	"github.com/go-mail/mail"
+	"github.com/spf13/viper"
+)
+
+// SMTPMailer is a SMTP mailer.
+type SMTPMailer struct {
+	client *mail.Dialer
+	from   Email
+}
+
+// NewMailer returns a configured SMTP Mailer.
+func NewMailer() (Mailer, error) {
+	if err := parseTemplates(); err != nil {
+		return nil, err
+	}
+
+	smtp := struct {
+		Host     string
+		Port     int
+		User     string
+		Password string
+	}{
+		viper.GetString("email_smtp_host"),
+		viper.GetInt("email_smtp_port"),
+		viper.GetString("email_smtp_user"),
+		viper.GetString("email_smtp_password"),
+	}
+
+	if smtp.Host == "" {
+		return NewMockMailer(), nil
+	}
+
+	s := &SMTPMailer{
+		client: mail.NewDialer(smtp.Host, smtp.Port, smtp.User, smtp.Password),
+		from:   NewEmail(viper.GetString("email_from_name"), viper.GetString("email_from_address")),
+	}
+
+	d, err := s.client.Dial()
+	if err == nil {
+		d.Close()
+		return s, nil
+	}
+	return nil, err
+}
+
+// Send sends the mail via smtp.
+func (m *SMTPMailer) Send(email Message) error {
+	if err := email.parse(); err != nil {
+		return err
+	}
+
+	msg := mail.NewMessage()
+	msg.SetAddressHeader("From", email.From.Address, email.From.Name)
+	msg.SetAddressHeader("To", email.To.Address, email.To.Name)
+	msg.SetHeader("Subject", email.Subject)
+	msg.SetBody("text/plain", email.text)
+	msg.AddAlternative("text/html", email.html)
+
+	return m.client.DialAndSend(msg)
+}