PDT24-34 | Configure nodemailer service (#12)

* feat: configure nodemailer servie for sending email

* feat: create a basic email template for sending signup otp code

* chore: rename param names and add function documentation

* fix: use secure mailing port

* refactor: remove sendEmail call from main and improve sendEmail method

package.json

@@ -37,6 +37,7 @@
 		"class-transformer": "^0.5.1",
 		"class-validator": "^0.14.1",
 		"nest-winston": "^1.9.7",
+		"nodemailer": "^6.9.16",
 		"pg": "^8.13.1",
 		"reflect-metadata": "^0.2.0",
 		"rxjs": "^7.8.1",
@@ -51,6 +52,7 @@
 		"@types/bcrypt": "^5.0.2",
 		"@types/express": "^5.0.0",
 		"@types/node": "^20.3.1",
+		"@types/nodemailer": "^6.4.17",
 		"@typescript-eslint/eslint-plugin": "^8.0.0",
 		"@typescript-eslint/parser": "^8.0.0",
 		"eslint": "^8.0.0",

src/mailer/dto/mailer.dto.ts

@@ -0,0 +1,8 @@
+import { Address } from 'nodemailer/lib/mailer';
+export class MailerDto {
+	sender?: Address;
+	recipients: Address[];
+	subject: string;
+	html: string;
+	text?: string;
+}

src/mailer/mailer.module.ts

@@ -0,0 +1,8 @@
+import { Module } from '@nestjs/common';
+import { MailerService } from './mailer.service';
+
+@Module({
+	providers: [MailerService],
+	exports: [MailerService],
+})
+export class MailerModule {}

src/mailer/mailer.service.ts

@@ -0,0 +1,36 @@
+import { createTransport, SendMailOptions, Transporter } from 'nodemailer';
+import { Logger } from '@nestjs/common';
+import { MailerDto } from '@/mailer/dto/mailer.dto';
+
+export class MailerService {
+	private readonly logger = new Logger();
+	transporter: Transporter = createTransport({
+		host: process.env.EMAIL_HOST,
+		port: 465,
+		secure: true,
+		auth: {
+			user: process.env.EMAIL_USER,
+			pass: process.env.EMAIL_PASS,
+		},
+	});
+
+	async sendEmail(data: MailerDto): Promise<void> {
+		try {
+			const { sender, recipients, subject, html, text } = data;
+			const mailOptions: SendMailOptions = {
+				from: sender ?? {
+					name: process.env.EMAIL_SENDER_NAME as string,
+					address: process.env.EMAIL_USER as string,
+				},
+				to: recipients,
+				subject,
+				html,
+				text,
+			};
+			await this.transporter.sendMail(mailOptions);
+			this.logger.log('Mail sent successfully');
+		} catch (error) {
+			this.logger.error(`Error sending email:`, { error });
+		}
+	}
+}

src/template/email.template.ts

@@ -0,0 +1,14 @@
+export const signupOtpMailTemplate = {
+	subject: 'Verify your account',
+	/**
+	 * Generates a random OTP of the specified size.
+	 * @param otpCode - code to send to through email.
+	 * @param userName - name of the user to send the email to.
+	 */
+	body: (otpCode: number, userName: string): string => `
+    <div>
+    <p>Welcome ${userName}</p>
+    <p>Use this code to verify your account:<br><b>${otpCode}</b>
+    </div>
+    `,
+};

yarn.lock

@@ -626,6 +626,13 @@
   dependencies:
     undici-types "~6.19.2"
 
+"@types/nodemailer@^6.4.17":
+  version "6.4.17"
+  resolved "https://registry.yarnpkg.com/@types/nodemailer/-/nodemailer-6.4.17.tgz#5c82a42aee16a3dd6ea31446a1bd6a447f1ac1a4"
+  integrity sha512-I9CCaIp6DTldEg7vyUTZi8+9Vo0hi1/T8gv3C89yk1rSAAzoKQ8H8ki/jBYJSFoH/BisgLP8tkZMlQ91CIquww==
+  dependencies:
+    "@types/node" "*"
+
 "@types/qs@*":
   version "6.9.17"
   resolved "https://registry.npmjs.org/@types/qs/-/qs-6.9.17.tgz"
@@ -3165,6 +3172,11 @@ node-releases@^2.0.18:
   resolved "https://registry.npmjs.org/node-releases/-/node-releases-2.0.19.tgz"
   integrity sha512-xxOWJsBKtzAq7DY0J+DTzuz58K8e7sJbdgwkbMWQe8UYB6ekmsQ45q0M/tJDsGaZmbC+l7n57UV8Hl5tHxO9uw==
 
+nodemailer@^6.9.16:
+  version "6.9.16"
+  resolved "https://registry.yarnpkg.com/nodemailer/-/nodemailer-6.9.16.tgz#3ebdf6c6f477c571c0facb0727b33892635e0b8b"
+  integrity sha512-psAuZdTIRN08HKVd/E8ObdV6NO7NTBY3KsC30F7M4H1OnmLCUNaS56FpYxyb26zWLSyYF9Ozch9KYHhHegsiOQ==
+
 nopt@^5.0.0:
   version "5.0.0"
   resolved "https://registry.npmjs.org/nopt/-/nopt-5.0.0.tgz"