feat(email): configurable reply-to address (#3140)

fluxer_api/pkgs/email/src/EmailProviderTypes.ts

@@ -4,6 +4,7 @@ export interface EmailConfig {
 	enabled: boolean;
 	fromEmail: string;
 	fromName: string;
+	replyTo?: string | null;
 	appBaseUrl: string;
 	marketingBaseUrl: string;
 }
@@ -14,6 +15,7 @@ export interface EmailMessage {
 		email: string;
 		name: string;
 	};
+	replyTo?: string;
 	subject: string;
 	text: string;
 }

fluxer_api/pkgs/email/src/EmailService.test.ts

@@ -0,0 +1,41 @@
+// SPDX-License-Identifier: AGPL-3.0-or-later
+
+import {EmailI18nService} from '@pkgs/email/src/EmailI18nService';
+import type {EmailConfig, EmailMessage, IEmailProvider} from '@pkgs/email/src/EmailProviderTypes';
+import {EmailService} from '@pkgs/email/src/EmailService';
+import {describe, expect, it} from 'vitest';
+
+const CONFIG: EmailConfig = {
+	enabled: true,
+	fromEmail: '[email protected]',
+	fromName: 'Fluxer',
+	appBaseUrl: 'https://example.com',
+	marketingBaseUrl: 'https://example.com',
+};
+
+async function sendWith(config: EmailConfig): Promise<EmailMessage> {
+	const sent: Array<EmailMessage> = [];
+	const provider: IEmailProvider = {
+		sendEmail: async (message) => {
+			sent.push(message);
+			return true;
+		},
+	};
+	const service = new EmailService(config, new EmailI18nService(), provider);
+	await expect(service.sendRegistrationApprovedEmail('[email protected]', 'testuser', 'en-US')).resolves.toBe(true);
+	expect(sent).toHaveLength(1);
+	return sent[0];
+}
+
+describe('EmailService reply-to', () => {
+	it('sets the configured reply-to address on every message', async () => {
+		const message = await sendWith({...CONFIG, replyTo: '[email protected]'});
+		expect(message.replyTo).toBe('[email protected]');
+		expect(message.from).toEqual({email: '[email protected]', name: 'Fluxer'});
+	});
+
+	it.each([undefined, null, ''])('omits the reply-to address when it is %j', async (replyTo) => {
+		const message = await sendWith({...CONFIG, replyTo});
+		expect(message).not.toHaveProperty('replyTo');
+	});
+});

fluxer_api/pkgs/email/src/EmailService.ts

@@ -375,6 +375,7 @@ export class EmailService implements IEmailService {
 		return this.provider.sendEmail({
 			to: email,
 			from: {email: this.config.fromEmail, name: this.config.fromName},
+			...(this.config.replyTo ? {replyTo: this.config.replyTo} : {}),
 			subject,
 			text: body,
 		});

fluxer_api/pkgs/email/src/SmtpEmailProvider.test.ts

@@ -0,0 +1,44 @@
+// SPDX-License-Identifier: AGPL-3.0-or-later
+
+import {SmtpEmailProvider} from '@pkgs/email/src/SmtpEmailProvider';
+import {beforeEach, describe, expect, it, vi} from 'vitest';
+
+const {sendMail} = vi.hoisted(() => ({sendMail: vi.fn()}));
+
+vi.mock('nodemailer', () => ({
+	default: {createTransport: () => ({sendMail, verify: vi.fn()})},
+}));
+
+const MESSAGE = {
+	to: '[email protected]',
+	from: {email: '[email protected]', name: 'Fluxer'},
+	subject: 'Subject',
+	text: 'Body',
+};
+
+function createProvider(): SmtpEmailProvider {
+	return new SmtpEmailProvider({host: 'smtp.example.com', port: 587, username: 'user', password: 'pass'});
+}
+
+describe('SmtpEmailProvider', () => {
+	beforeEach(() => {
+		sendMail.mockReset();
+		sendMail.mockResolvedValue({});
+	});
+
+	it('passes the reply-to address to nodemailer', async () => {
+		await expect(createProvider().sendEmail({...MESSAGE, replyTo: '[email protected]'})).resolves.toBe(true);
+		expect(sendMail).toHaveBeenCalledWith({
+			to: '[email protected]',
+			from: 'Fluxer <[email protected]>',
+			replyTo: '[email protected]',
+			subject: 'Subject',
+			text: 'Body',
+		});
+	});
+
+	it('omits the reply-to address when the message has none', async () => {
+		await expect(createProvider().sendEmail(MESSAGE)).resolves.toBe(true);
+		expect(sendMail.mock.calls[0][0]).not.toHaveProperty('replyTo');
+	});
+});

fluxer_api/pkgs/email/src/SmtpEmailProvider.ts

@@ -45,6 +45,7 @@ export class SmtpEmailProvider implements IEmailProvider {
 			await this.transporter.sendMail({
 				to: message.to,
 				from: `${message.from.name} <${message.from.email}>`,
+				...(message.replyTo ? {replyTo: message.replyTo} : {}),
 				subject: message.subject,
 				text: message.text,
 			});

fluxer_api/src/api/Config.ts

@@ -248,6 +248,7 @@ export function buildAPIConfigFromMaster(master: MasterConfig): APIConfig {
 			webhookSecret: master.integrations.email.webhook_secret ?? undefined,
 			fromEmail: master.integrations.email.from_email,
 			fromName: master.integrations.email.from_name,
+			replyToEmail: master.integrations.email.reply_to_email,
 			appBaseUrl: resolveEmailAppBaseUrl(master),
 			smtp: master.integrations.email.smtp
 				? {

fluxer_api/src/api/config/APIConfig.ts

@@ -155,6 +155,7 @@ export interface APIConfig {
 		webhookSecret?: string;
 		fromEmail: string;
 		fromName: string;
+		replyToEmail: string;
 		appBaseUrl: string;
 		smtp?: {
 			host: string;

fluxer_api/src/api/middleware/ServiceSingletons.ts

@@ -187,6 +187,7 @@ function createEmailServiceForConfig(
 		enabled: emailConfigSource.enabled,
 		fromEmail: emailConfigSource.fromEmail,
 		fromName: emailConfigSource.fromName,
+		replyTo: emailConfigSource.replyToEmail || null,
 		appBaseUrl: emailConfigSource.appBaseUrl,
 		marketingBaseUrl: Config.endpoints.marketing,
 	};