implemented smtp mail service in go

Makefile

@@ -25,7 +25,7 @@ sqlc:
 	sqlc generate
 
 test:
-	go test -v -cover ./...
+	go test -v -cover -short ./...
 
 server:
 	go run main.go

go.mod

@@ -12,6 +12,7 @@ require (
 	github.com/google/uuid v1.6.0
 	github.com/grpc-ecosystem/grpc-gateway/v2 v2.27.1
 	github.com/hibiken/asynq v0.25.1
+	github.com/jordan-wright/email v4.0.1-0.20210109023952-943e75fe5223+incompatible
 	github.com/lib/pq v1.10.9
 	github.com/o1egl/paseto v1.0.0
 	github.com/rakyll/statik v0.1.7

go.sum

@@ -91,6 +91,8 @@ github.com/hashicorp/go-multierror v1.1.1 h1:H5DkEtf6CXdFp0N0Em5UCwQpXMWke8IA0+l
 github.com/hashicorp/go-multierror v1.1.1/go.mod h1:iw975J/qwKPdAO1clOe2L8331t/9/fmwbPZ6JB6eMoM=
 github.com/hibiken/asynq v0.25.1 h1:phj028N0nm15n8O2ims+IvJ2gz4k2auvermngh9JhTw=
 github.com/hibiken/asynq v0.25.1/go.mod h1:pazWNOLBu0FEynQRBvHA26qdIKRSmfdIfUm4HdsLmXg=
+github.com/jordan-wright/email v4.0.1-0.20210109023952-943e75fe5223+incompatible h1:jdpOPRN1zP63Td1hDQbZW73xKmzDvZHzVdNYxhnTMDA=
+github.com/jordan-wright/email v4.0.1-0.20210109023952-943e75fe5223+incompatible/go.mod h1:1c7szIrayyPPB/987hsnvNzLushdWf4o/79s3P08L8A=
 github.com/json-iterator/go v1.1.12 h1:PV8peI4a0ysnczrg+LtxykD8LfKY9ML6u2jnxaEnrnM=
 github.com/json-iterator/go v1.1.12/go.mod h1:e30LSqwooZae/UwlEbR2852Gd8hjQvJoHmT4TnhNGBo=
 github.com/klauspost/cpuid/v2 v2.0.9/go.mod h1:FInQzS24/EEf25PyTYn52gqo7WaD8xa0213Md/qVLRg=

mail/sender.go

@@ -0,0 +1,65 @@
+package mail
+
+import (
+	"fmt"
+	"net/smtp"
+
+	"github.com/jordan-wright/email"
+)
+
+const (
+	smtpAuthAddress = "smtp.gmail.com"
+	smtpServerAddrss = "smtp.gmail.com:587"
+)
+
+type EmailSender interface {
+	SendEmail(
+		subject string,
+		content string,
+		to []string,
+		cc []string,
+		bcc []string,
+		attachFiles []string,
+	) error
+}
+
+type GmailSender struct {
+	name string
+	fromEmailAddress string
+	fromEmailPassword string
+}
+
+func NewGmailSender(name, fromEmailAddress, fromEmailPassword string) EmailSender {
+	return &GmailSender{
+		name: name,
+		fromEmailAddress: fromEmailAddress,
+		fromEmailPassword: fromEmailPassword,
+	}
+}
+
+func (sender *GmailSender) SendEmail(
+		subject string,
+		content string,
+		to []string,
+		cc []string,
+		bcc []string,
+		attachFiles []string,
+) error {
+	e := email.NewEmail()
+	e.From = fmt.Sprintf("%s <%s>", sender.name, sender.fromEmailAddress)
+	e.Subject = subject 
+	e.HTML = []byte(content)
+	e.To = to
+	e.Cc = cc
+	e.Bcc = bcc
+
+	for _, f := range attachFiles {
+		_, err := e.AttachFile(f)
+		if err != nil {
+			return fmt.Errorf("failed to attach file %s: %v", f, err)
+		}
+	}
+
+	smtpAuth := smtp.PlainAuth("", sender.fromEmailAddress, sender.fromEmailPassword, smtpAuthAddress)
+	return e.Send(smtpServerAddrss, smtpAuth)
+}

mail/sender_test.go

@@ -0,0 +1,37 @@
+package mail
+
+import (
+	"testing"
+
+	"github.com/Samudra-G/simplebank/util"
+	"github.com/stretchr/testify/require"
+)
+
+func TestSendEmailWithGmail(t *testing.T) {
+	if(testing.Short()) {
+		t.Skip()
+	}
+
+	config, err := util.LoadConfig("..")
+	require.NoError(t, err)
+
+	sender := NewGmailSender(config.EmailSenderName, config.EmailSenderAddress, config.EmailSenderPassword)
+
+	subject := "Test Email"
+	content := `
+	<h1>Hello, test email</h1>
+	<p>This is a test email sent from the Simple Bank application by <a href="https://samudra-portfolio.vercel.app/"> Samudra G</p>
+	`
+	to := []string{"samudramukhar@gmail.com"}
+	attachFiles := []string{"../README.md"}
+
+	err = sender.SendEmail(
+		subject,
+		content,
+		to,
+		nil,
+		nil,
+		attachFiles,
+	)
+	require.NoError(t, err, "Failed to send email")
+}	

util/config.go

@@ -19,6 +19,9 @@ type Config struct {
 	TokenSymmetricKey    string 		   `mapstructure:"TOKEN_SYMMETRIC_KEY"`
 	AccessTokenDuration  time.Duration     `mapstructure:"ACCESS_TOKEN_DURATION"`
 	RefreshTokenDuration time.Duration     `mapstructure:"REFRESH_TOKEN_DURATION"`
+	EmailSenderName      string 		   `mapstructure:"EMAIL_SENDER_NAME"`
+	EmailSenderAddress   string 		   `mapstructure:"EMAIL_SENDER_ADDRESS"`
+	EmailSenderPassword  string 		   `mapstructure:"EMAIL_SENDER_PASSWORD"`
 }
 
 //LoadConfig reads configuration from a file or environment variables