feat: event emitter added

packages/hoppscotch-backend/package.json

@@ -30,6 +30,7 @@
     "@nestjs/common": "10.2.7",
     "@nestjs/config": "3.1.1",
     "@nestjs/core": "10.2.7",
+    "@nestjs/event-emitter": "2.0.4",
     "@nestjs/graphql": "12.0.9",
     "@nestjs/jwt": "10.1.1",
     "@nestjs/passport": "10.0.2",

packages/hoppscotch-backend/src/admin/admin.service.ts

@@ -19,7 +19,6 @@ import {
   USER_IS_ADMIN,
   USER_NOT_FOUND,
 } from '../errors';
-import { MailerService } from '../mailer/mailer.service';
 import { InvitedUser } from './invited-user.model';
 import { TeamService } from '../team/team.service';
 import { TeamCollectionService } from '../team-collection/team-collection.service';
@@ -31,6 +30,8 @@ import { ShortcodeService } from 'src/shortcode/shortcode.service';
 import { ConfigService } from '@nestjs/config';
 import { OffsetPaginationArgs } from 'src/types/input-types.args';
 import { UserDeletionResult } from 'src/user/user.model';
+import { EventEmitter2 } from '@nestjs/event-emitter';
+import { Events } from 'src/types/EventEmitter';
 
 @Injectable()
 export class AdminService {
@@ -43,9 +44,9 @@ export class AdminService {
     private readonly teamInvitationService: TeamInvitationService,
     private readonly pubsub: PubSubService,
     private readonly prisma: PrismaService,
-    private readonly mailerService: MailerService,
     private readonly shortcodeService: ShortcodeService,
     private readonly configService: ConfigService,
+    private readonly eventEmitter: EventEmitter2,
   ) {}
 
   /**
@@ -99,17 +100,16 @@ export class AdminService {
     });
     if (alreadyInvitedUser != null) return E.left(USER_ALREADY_INVITED);
 
-    try {
-      await this.mailerService.sendUserInvitationEmail(inviteeEmail, {
+    this.eventEmitter.emit(Events.MAILER_SEND_USER_INVITATION_EMAIL, {
+      to: inviteeEmail,
+      mailDesc: {
         template: 'user-invitation',
         variables: {
           inviteeEmail: inviteeEmail,
           magicLink: `${this.configService.get('VITE_BASE_URL')}`,
         },
-      });
-    } catch (e) {
-      return E.left(EMAIL_FAILED);
-    }
+      },
+    });
 
     // Add invitee email to the list of invited users by admin
     const dbInvitedUser = await this.prisma.invitedUsers.create({

packages/hoppscotch-backend/src/app.module.ts

@@ -27,9 +27,11 @@ import { MailerModule } from './mailer/mailer.module';
 import { PosthogModule } from './posthog/posthog.module';
 import { ScheduleModule } from '@nestjs/schedule';
 import { HealthModule } from './health/health.module';
+import { EventEmitterModule } from '@nestjs/event-emitter';
 
 @Module({
   imports: [
+    EventEmitterModule.forRoot(),
     ConfigModule.forRoot({
       isGlobal: true,
       load: [async () => loadInfraConfiguration()],

packages/hoppscotch-backend/src/auth/auth.service.ts

@@ -1,5 +1,4 @@
 import { HttpStatus, Injectable } from '@nestjs/common';
-import { MailerService } from 'src/mailer/mailer.service';
 import { PrismaService } from 'src/prisma/prisma.service';
 import { UserService } from 'src/user/user.service';
 import { VerifyMagicDto } from './dto/verify-magic.dto';
@@ -30,6 +29,8 @@ import { VerificationToken } from '@prisma/client';
 import { Origin } from './helper';
 import { ConfigService } from '@nestjs/config';
 import { InfraConfigService } from 'src/infra-config/infra-config.service';
+import { EventEmitter2 } from '@nestjs/event-emitter';
+import { Events } from 'src/types/EventEmitter';
 
 @Injectable()
 export class AuthService {
@@ -37,9 +38,9 @@ export class AuthService {
     private usersService: UserService,
     private prismaService: PrismaService,
     private jwtService: JwtService,
-    private readonly mailerService: MailerService,
     private readonly configService: ConfigService,
     private infraConfigService: InfraConfigService,
+    private eventEmitter: EventEmitter2,
   ) {}
 
   /**
@@ -234,11 +235,14 @@ export class AuthService {
         url = this.configService.get('VITE_BASE_URL');
     }
 
-    await this.mailerService.sendEmail(email, {
-      template: 'user-invitation',
-      variables: {
-        inviteeEmail: email,
-        magicLink: `${url}/enter?token=${generatedTokens.token}`,
+    this.eventEmitter.emit(Events.MAILER_SEND_EMAIL, {
+      to: email,
+      mailDesc: {
+        template: 'user-invitation',
+        variables: {
+          inviteeEmail: email,
+          magicLink: `${url}/enter?token=${generatedTokens.token}`,
+        },
       },
     });
 

packages/hoppscotch-backend/src/mailer/mailer.listener.ts

@@ -0,0 +1,30 @@
+import { Injectable } from '@nestjs/common';
+import { OnEvent } from '@nestjs/event-emitter';
+import { Events } from 'src/types/EventEmitter';
+import {
+  AdminUserInvitationMailDescription,
+  MailDescription,
+  UserMagicLinkMailDescription,
+} from './MailDescriptions';
+import { MailerService } from './mailer.service';
+
+@Injectable()
+export class MailerEventListener {
+  constructor(private mailerService: MailerService) {}
+
+  @OnEvent(Events.MAILER_SEND_EMAIL, { async: true })
+  async handleSendEmailEvent(data: {
+    to: string;
+    mailDesc: MailDescription | UserMagicLinkMailDescription;
+  }) {
+    await this.mailerService.sendEmail(data.to, data.mailDesc);
+  }
+
+  @OnEvent(Events.MAILER_SEND_USER_INVITATION_EMAIL, { async: true })
+  async handleSendUserInvitationEmailEvent(data: {
+    to: string;
+    mailDesc: AdminUserInvitationMailDescription;
+  }) {
+    await this.mailerService.sendUserInvitationEmail(data.to, data.mailDesc);
+  }
+}

packages/hoppscotch-backend/src/mailer/mailer.module.ts

@@ -9,17 +9,21 @@ import {
 } from 'src/errors';
 import { ConfigService } from '@nestjs/config';
 import { loadInfraConfiguration } from 'src/infra-config/helper';
+import { MailerEventListener } from './mailer.listener';
 
 @Global()
-@Module({
-  imports: [],
-  providers: [MailerService],
-  exports: [MailerService],
-})
+@Module({})
 export class MailerModule {
   static async register() {
     const env = await loadInfraConfiguration();
 
+    // If mailer SMTP is DISABLED, return the module without any configuration
+    if (env.INFRA.MAILER_SMTP_ENABLE !== 'true') {
+      console.log('Mailer SMTP is disabled');
+      return { module: MailerModule };
+    }
+
+    // If mailer is ENABLED, return the module with configuration
     let mailerSmtpUrl = env.INFRA.MAILER_SMTP_URL;
     let mailerAddressFrom = env.INFRA.MAILER_ADDRESS_FROM;
 
@@ -31,6 +35,7 @@ export class MailerModule {
 
     return {
       module: MailerModule,
+      providers: [MailerService, MailerEventListener],
       imports: [
         NestMailerModule.forRoot({
           transport: mailerSmtpUrl ?? throwErr(MAILER_SMTP_URL_UNDEFINED),

packages/hoppscotch-backend/src/mailer/mailer.service.ts

@@ -7,10 +7,14 @@ import {
 import { throwErr } from 'src/utils';
 import { EMAIL_FAILED } from 'src/errors';
 import { MailerService as NestMailerService } from '@nestjs-modules/mailer';
+import { ConfigService } from '@nestjs/config';
 
 @Injectable()
 export class MailerService {
-  constructor(private readonly nestMailerService: NestMailerService) {}
+  constructor(
+    private readonly nestMailerService: NestMailerService,
+    private readonly configService: ConfigService,
+  ) {}
 
   /**
    * Takes an input mail description and spits out the Email subject required for it
@@ -42,6 +46,8 @@ export class MailerService {
     to: string,
     mailDesc: MailDescription | UserMagicLinkMailDescription,
   ) {
+    if (this.configService.get('INFRA.MAILER_SMTP_ENABLE') !== 'true') return;
+
     try {
       await this.nestMailerService.sendMail({
         to,
@@ -64,6 +70,8 @@ export class MailerService {
     to: string,
     mailDesc: AdminUserInvitationMailDescription,
   ) {
+    if (this.configService.get('INFRA.MAILER_SMTP_ENABLE') !== 'true') return;
+
     try {
       const res = await this.nestMailerService.sendMail({
         to,

packages/hoppscotch-backend/src/team-invitation/team-invitation.service.ts

@@ -15,12 +15,13 @@ import {
   TEAM_MEMBER_NOT_FOUND,
 } from 'src/errors';
 import { TeamInvitation } from './team-invitation.model';
-import { MailerService } from 'src/mailer/mailer.service';
 import { UserService } from 'src/user/user.service';
 import { PubSubService } from 'src/pubsub/pubsub.service';
 import { validateEmail } from '../utils';
 import { AuthUser } from 'src/types/AuthUser';
 import { ConfigService } from '@nestjs/config';
+import { EventEmitter2 } from '@nestjs/event-emitter';
+import { Events } from 'src/types/EventEmitter';
 
 @Injectable()
 export class TeamInvitationService {
@@ -28,9 +29,9 @@ export class TeamInvitationService {
     private readonly prisma: PrismaService,
     private readonly userService: UserService,
     private readonly teamService: TeamService,
-    private readonly mailerService: MailerService,
     private readonly pubsub: PubSubService,
     private readonly configService: ConfigService,
+    private eventEmitter: EventEmitter2,
   ) {}
 
   /**
@@ -147,14 +148,17 @@ export class TeamInvitationService {
       },
     });
 
-    await this.mailerService.sendEmail(inviteeEmail, {
-      template: 'team-invitation',
-      variables: {
-        invitee: creator.displayName ?? 'A Hoppscotch User',
-        action_url: `${this.configService.get('VITE_BASE_URL')}/join-team?id=${
-          dbInvitation.id
-        }`,
-        invite_team_name: team.name,
+    this.eventEmitter.emit(Events.MAILER_SEND_EMAIL, {
+      to: inviteeEmail,
+      mailDesc: {
+        template: 'team-invitation',
+        variables: {
+          invitee: creator.displayName ?? 'A Hoppscotch User',
+          action_url: `${this.configService.get(
+            'VITE_BASE_URL',
+          )}/join-team?id=${dbInvitation.id}`,
+          invite_team_name: team.name,
+        },
       },
     });
 

packages/hoppscotch-backend/src/types/EventEmitter.ts

@@ -0,0 +1,4 @@
+export enum Events {
+  MAILER_SEND_EMAIL = 'mailer.sendEmail',
+  MAILER_SEND_USER_INVITATION_EMAIL = 'mailer.sendUserInvitationEmail',
+}