♻️ Improve email abstraction (#863)

apps/landing/playwright.config.ts

@@ -1,34 +0,0 @@
-import { devices, PlaywrightTestConfig } from "@playwright/test";
-
-const ci = process.env.CI === "true";
-
-// Use process.env.PORT by default and fallback to port 3000
-const PORT = process.env.PORT || 3000;
-
-// Set webServer.url and use.baseURL with the location of the WebServer respecting the correct set port
-const baseURL = `http://localhost:${PORT}`;
-
-// Reference: https://playwright.dev/docs/test-configuration
-const config: PlaywrightTestConfig = {
-  // Artifacts folder where screenshots, videos, and traces are stored.
-  outputDir: "test-results/",
-  projects: [{ name: "chromium", use: { ...devices["Desktop Chrome"] } }],
-  use: {
-    viewport: { width: 1280, height: 720 },
-    baseURL,
-    permissions: ["clipboard-read"],
-    trace: "retain-on-failure",
-  },
-  webServer: {
-    command: `NODE_ENV=test yarn dev --port ${PORT}`,
-    url: baseURL,
-    timeout: 120 * 1000,
-    reuseExistingServer: !ci,
-  },
-  reporter: [
-    [ci ? "github" : "list"],
-    ["html", { open: !ci ? "on-failure" : "never" }],
-  ],
-  workers: 1,
-};
-export default config;

packages/backend/trpc/context.ts

@@ -1,3 +1,4 @@
+import { EmailClient, SupportedEmailProviders } from "@rallly/emails";
 import { createProxySSGHelpers } from "@trpc/react-query/ssg";
 import * as trpc from "@trpc/server";
 import * as trpcNext from "@trpc/server/adapters/next";
@@ -7,6 +8,9 @@ import superjson from "superjson";
 import { randomid } from "../utils/nanoid";
 import { appRouter } from "./routers";
 
+// Avoid use NODE_ENV directly because it will be replaced when using the dev server for e2e tests
+const env = process.env["NODE" + "_ENV"];
+
 export async function createContext(
   opts: trpcNext.CreateNextContextOptions | GetServerSidePropsContext,
 ) {
@@ -19,12 +23,30 @@ export async function createContext(
     opts.req.session.user = user;
     await opts.req.session.save();
   }
+
+  const emailClient = new EmailClient({
+    openPreviews: env === "development",
+    useTestServer: env === "test",
+    provider: {
+      name: (process.env.EMAIL_PROVIDER as SupportedEmailProviders) ?? "smtp",
+    },
+    mail: {
+      from: {
+        name: "Rallly",
+        address:
+          (process.env.NOREPLY_EMAIL as string) ||
+          (process.env.SUPPORT_EMAIL as string),
+      },
+    },
+  });
+
   return {
     user,
     session: opts.req.session,
     req: opts.req,
     res: opts.res,
     isSelfHosted: process.env.NEXT_PUBLIC_SELF_HOSTED === "true",
+    emailClient,
   };
 }
 

packages/backend/trpc/routers/auth.ts

@@ -1,5 +1,4 @@
 import { prisma } from "@rallly/database";
-import { sendEmail } from "@rallly/emails";
 import { absoluteUrl } from "@rallly/utils";
 import { TRPCError } from "@trpc/server";
 import { z } from "zod";
@@ -78,6 +77,7 @@ export const auth = router({
     .mutation(
       async ({
         input,
+        ctx,
       }): Promise<
         | { ok: true; token: string }
         | { ok: false; reason: "userAlreadyExists" | "emailNotAllowed" }
@@ -107,7 +107,7 @@ export const auth = router({
           code,
         });
 
-        await sendEmail("RegisterEmail", {
+        await ctx.emailClient.sendTemplate("RegisterEmail", {
           to: input.email,
           subject: `${input.name}, please verify your email address`,
           props: {
@@ -168,6 +168,7 @@ export const auth = router({
     .mutation(
       async ({
         input,
+        ctx,
       }): Promise<
         | { ok: true; token: string }
         | { ok: false; reason: "emailNotAllowed" | "userNotFound" }
@@ -193,7 +194,7 @@ export const auth = router({
           code,
         });
 
-        await sendEmail("LoginEmail", {
+        await ctx.emailClient.sendTemplate("LoginEmail", {
           to: input.email,
           subject: `${code} is your 6-digit code`,
           props: {

packages/backend/trpc/routers/polls.ts

@@ -1,5 +1,4 @@
 import { prisma } from "@rallly/database";
-import { sendEmail } from "@rallly/emails";
 import { absoluteUrl, shortUrl } from "@rallly/utils";
 import { TRPCError } from "@trpc/server";
 import dayjs from "dayjs";
@@ -133,7 +132,7 @@ export const polls = router({
         });
 
         if (user) {
-          await sendEmail("NewPollEmail", {
+          await ctx.emailClient.sendTemplate("NewPollEmail", {
             to: user.email,
             subject: `Let's find a date for ${poll.title}`,
             props: {
@@ -678,7 +677,7 @@ export const polls = router({
           });
         }
 
-        const emailToHost = sendEmail("FinalizeHostEmail", {
+        const emailToHost = ctx.emailClient.sendTemplate("FinalizeHostEmail", {
           subject: `Date booked for ${poll.title}`,
           to: poll.user.email,
           props: {
@@ -702,7 +701,7 @@ export const polls = router({
         });
 
         const emailsToParticipants = participantsToEmail.map((p) => {
-          return sendEmail("FinalizeParticipantEmail", {
+          return ctx.emailClient.sendTemplate("FinalizeParticipantEmail", {
             subject: `Date booked for ${poll.title}`,
             to: p.email,
             props: {

packages/backend/trpc/routers/polls/comments.ts

@@ -1,5 +1,4 @@
 import { prisma } from "@rallly/database";
-import { sendEmail } from "@rallly/emails";
 import { absoluteUrl } from "@rallly/utils";
 import { z } from "zod";
 
@@ -82,7 +81,7 @@ export const comments = router({
           { ttl: 0 },
         );
         emailsToSend.push(
-          sendEmail("NewCommentEmail", {
+          ctx.emailClient.sendTemplate("NewCommentEmail", {
             to: email,
             subject: `${authorName} has commented on ${poll.title}`,
             props: {

packages/backend/trpc/routers/polls/participants.ts

@@ -1,5 +1,4 @@
 import { prisma } from "@rallly/database";
-import { sendEmail } from "@rallly/emails";
 import { absoluteUrl } from "@rallly/utils";
 import { TRPCError } from "@trpc/server";
 import { z } from "zod";
@@ -107,7 +106,7 @@ export const participants = router({
         );
 
         emailsToSend.push(
-          sendEmail("NewParticipantConfirmationEmail", {
+          ctx.emailClient.sendTemplate("NewParticipantConfirmationEmail", {
             to: email,
             subject: `Thanks for responding to ${poll.title}`,
             props: {
@@ -144,7 +143,7 @@ export const participants = router({
           { ttl: 0 },
         );
         emailsToSend.push(
-          sendEmail("NewParticipantEmail", {
+          ctx.emailClient.sendTemplate("NewParticipantEmail", {
             to: email,
             subject: `${participant.name} has responded to ${poll.title}`,
             props: {

packages/emails/package.json

@@ -7,8 +7,8 @@
     "lint": "eslint ./src",
     "lint:tsc": "tsc --noEmit"
   },
-  "main": "./src/index.tsx",
-  "types": "./src/index.tsx",
+  "main": "./src/index.ts",
+  "types": "./src/index.ts",
   "dependencies": {
     "@aws-sdk/client-ses": "^3.292.0",
     "@aws-sdk/credential-provider-node": "^3.292.0",
@@ -16,12 +16,14 @@
     "@react-email/render": "0.0.6",
     "clsx": "^1.2.1",
     "nodemailer": "^6.9.1",
+    "preview-email": "^3.0.19",
     "react-email": "^1.9.1"
   },
   "devDependencies": {
     "@rallly/tailwind-config": "*",
     "@rallly/tsconfig": "*",
     "@rallly/utils": "*",
-    "@types/nodemailer": "^6.4.7"
+    "@types/nodemailer": "^6.4.7",
+    "@types/preview-email": "^3.0.1"
   }
 }

packages/emails/src/send-email.tsx

@@ -3,6 +3,7 @@ import { defaultProvider } from "@aws-sdk/credential-provider-node";
 import { render } from "@react-email/render";
 import { createTransport, Transporter } from "nodemailer";
 import type Mail from "nodemailer/lib/mailer";
+import previewEmail from "preview-email";
 import React from "react";
 
 import * as templates from "./templates";
@@ -17,41 +18,131 @@ type TemplateProps<T extends TemplateName> = React.ComponentProps<
 
 type TemplateComponent<T extends TemplateName> = Templates[T];
 
-const env = process.env["NODE" + "_ENV"] || "development";
+type SendEmailOptions<T extends TemplateName> = {
+  to: string;
+  subject: string;
+  props: TemplateProps<T>;
+  attachments?: Mail.Options["attachments"];
+};
 
-let transport: Transporter;
+type EmailProviderConfig =
+  | {
+      name: "ses";
+      // config defined through env vars
+    }
+  | {
+      name: "smtp";
+      // config defined through env vars
+    };
 
-const getTransport = () => {
-  if (transport) {
+export type SupportedEmailProviders = EmailProviderConfig["name"];
+
+type EmailClientConfig = {
+  /**
+   * Whether to open previews of each email in the browser
+   */
+  openPreviews?: boolean;
+  /**
+   * Whether to send emails to the test server
+   */
+  useTestServer: boolean;
+  /**
+   * Email provider config
+   */
+  provider: EmailProviderConfig;
+  /**
+   * Mail config
+   */
+  mail: {
+    from: {
+      name: string;
+      address: string;
+    };
+  };
+};
+
+export class EmailClient {
+  private config: EmailClientConfig;
+  private cachedTransport?: Transporter;
+
+  constructor(config: EmailClientConfig) {
+    this.config = config;
+  }
+
+  async sendTemplate<T extends TemplateName>(
+    templateName: T,
+    options: SendEmailOptions<T>,
+  ) {
+    if (!process.env.SUPPORT_EMAIL) {
+      console.info("SUPPORT_EMAIL not configured - skipping email send");
+      return;
+    }
+
+    const Template = templates[templateName] as TemplateComponent<T>;
+    // eslint-disable-next-line @typescript-eslint/no-explicit-any
+    const html = render(<Template {...(options.props as any)} />);
+
+    try {
+      await this.sendEmail({
+        from: this.config.mail.from,
+        to: options.to,
+        subject: options.subject,
+        // eslint-disable-next-line @typescript-eslint/no-explicit-any
+        html,
+        attachments: options.attachments,
+      });
+    } catch (e) {
+      console.error("Error sending email", templateName, e);
+    }
+  }
+
+  async sendEmail(options: Mail.Options) {
+    if (this.config.openPreviews) {
+      previewEmail(options, {
+        openSimulator: false,
+      });
+    }
+
+    try {
+      await this.transport.sendMail(options);
+      return;
+    } catch (e) {
+      console.error("Error sending email", e);
+    }
+  }
+
+  private get transport() {
+    if (this.cachedTransport) {
       // Reuse the transport if it exists
-    return transport;
+      return this.cachedTransport;
     }
 
-  if (env === "test") {
-    transport = createTransport({ port: 4025 });
-    return transport;
+    if (this.config.useTestServer) {
+      this.cachedTransport = createTransport({
+        port: 4025,
+      });
+      return this.cachedTransport;
     }
 
-  switch (process.env.EMAIL_PROVIDER) {
-    case "ses":
-      {
+    switch (this.config.provider.name) {
+      case "ses": {
         const ses = new aws.SES({
           region: process.env["AWS" + "_REGION"],
           credentialDefaultProvider: defaultProvider,
         });
 
-        transport = createTransport({
+        this.cachedTransport = createTransport({
           SES: {
             ses,
             aws,
             sendingRate: 10,
           },
         });
-      }
         break;
-    default: {
+      }
+      case "smtp": {
         const hasAuth = process.env.SMTP_USER || process.env.SMTP_PWD;
-      transport = createTransport({
+        this.cachedTransport = createTransport({
           host: process.env.SMTP_HOST,
           port: process.env.SMTP_PORT
             ? parseInt(process.env.SMTP_PORT)
@@ -71,55 +162,10 @@ const getTransport = () => {
                 }
               : undefined,
         });
+        break;
       }
     }
 
-  return transport;
-};
-
-type SendEmailOptions<T extends TemplateName> = {
-  to: string;
-  subject: string;
-  props: TemplateProps<T>;
-  attachments?: Mail.Options["attachments"];
-};
-
-export const sendEmail = async <T extends TemplateName>(
-  templateName: T,
-  options: SendEmailOptions<T>,
-) => {
-  if (!process.env.SUPPORT_EMAIL) {
-    console.info("SUPPORT_EMAIL not configured - skipping email send");
-    return;
+    return this.cachedTransport;
   }
-
-  const Template = templates[templateName] as TemplateComponent<T>;
-  // eslint-disable-next-line @typescript-eslint/no-explicit-any
-  const html = render(<Template {...(options.props as any)} />);
-
-  try {
-    await sendRawEmail({
-      from: {
-        name: "Rallly",
-        address: process.env.NOREPLY_EMAIL || process.env.SUPPORT_EMAIL,
-      },
-      to: options.to,
-      subject: options.subject,
-      // eslint-disable-next-line @typescript-eslint/no-explicit-any
-      html,
-      attachments: options.attachments,
-    });
-  } catch (e) {
-    console.error("Error sending email", templateName, e);
 }
-};
-
-export const sendRawEmail = async (options: Mail.Options) => {
-  const transport = getTransport();
-  try {
-    await transport.sendMail(options);
-    return;
-  } catch (e) {
-    console.error("Error sending email", e);
-  }
-};