Add email download

src/emlFile.ts

@@ -0,0 +1,27 @@
+import { createTransport, Transporter } from "nodemailer";
+import { convertToMailOptions, Email } from "./store";
+
+export interface CreateEmlContentResult {
+  messageId: string,
+  error?: string,
+  fileName: string,
+  body: string
+}
+
+export const createEmlContent = async (email: Email): Promise<CreateEmlContentResult> => {
+
+  const transporter: Transporter = createTransport({
+    streamTransport: true,
+    buffer: true,
+  });
+
+  return new Promise((resolve, reject) => {
+    transporter.sendMail(convertToMailOptions(email), (error, info) => {
+      if (!error) {
+        resolve({ messageId: email.messageId, fileName: email.subject, body: info.message });
+      } else {
+        reject({ messageId: email.messageId, error: `failed to create eml file content, ${error.message}` });
+      }
+    });
+  })
+};

src/index.ts

@@ -8,7 +8,8 @@ import v2DeleteEmailTemplate from './v2/deleteEmailTemplate';
 import v2GetAccount from './v2/getAccount';
 import v2SendEmail from './v2/sendEmail';
 import v2SendBulkEmail from './v2/sendBulkEmail';
-import { getStoreReadonly, clearStore } from './store';
+import { getStoreReadonly, clearStore, Email } from './store';
+import { createEmlContent } from './emlFile';
 
 export interface Config {
   host: string,
@@ -62,6 +63,27 @@ const server = (partialConfig: Partial<Config> = {}): Promise<Server> => {
   app.get('/health-check', (req, res) => {
     res.status(200).send();
   });
+
+  app.get('/get-emlContent', (req, res) => {
+    const store = getStoreReadonly();
+
+    if (typeof req.query.messageId !== 'string' || req.query.messageId === '') {
+      res.status(400).send({ message: 'Bad since query param, expected single value' });
+    }
+
+    const messageId = req.query.messageId as string;
+    const email = store.emails.find(e => e.messageId === messageId);
+
+    if (email === undefined) {
+      res.status(400).send({ message: 'Email not found within the store' })
+    }
+
+    createEmlContent(email as Email).then((result) => {
+      res.status(200).send(result);
+    }).catch((result) => {
+      res.status(400).send({ message: result.error });
+    });
+  });
 
   app.use((req, res, next) => {
     const authHeader = req.header('authorization');

src/store.ts

@@ -1,4 +1,5 @@
 import { sendEmailToSmtp } from './smtp';
+import { MailOptions } from 'nodemailer/lib/sendmail-transport';
 
 export interface Store {
   emails: Email[],
@@ -56,3 +57,16 @@ export const clearStore = () => {
 // But this is probably safe enough for now, given the method name
 // and the relatively small project size.
 export const getStoreReadonly = (): Readonly<Store> => store;
+
+export const convertToMailOptions = (email: Email): MailOptions => ({
+  from: email.from,
+  replyTo: email.replyTo,
+  to: email.destination.to,
+  cc: email.destination.cc,
+  bcc: email.destination.bcc,
+  subject: email.subject,
+  html: email.body.html,
+  text: email.body.text,
+  attachments: email.attachments,
+  date: new Date(email.at * 1000)
+});

static/index.html

@@ -246,6 +246,7 @@ <h2>Error: You need JavaScript enabled for this page to work.</h2>
                     ${e.body.text ? `<button onclick="toggle('${e.messageId}-text')">Toggle text view</button>` : ''}
                     ${e.body.html ? `<button onclick="toggle('${e.messageId}-html')">Toggle HTML view</button>` : ''}
                     ${e.body.html ? `<button onclick="toggle('${e.messageId}-source')">Toggle HTML source view</button>` : ''}
+                    <button onclick="downloadEmail('${e.messageId}')">Email Download</button>
 
                     ${e.body.text ? `<div class="email-text" id="${e.messageId}-text" style="display: none">${escape(e.body.text)}</div>` : ''}
                     ${e.body.html ? `<div class="email-html" id="${e.messageId}-html" style="display: none"><iframe id="${e.messageId}-html-iframe" src="javascript:void(0);"></iframe></div>` : ''}
@@ -307,6 +308,23 @@ <h2>Error: You need JavaScript enabled for this page to work.</h2>
             location.reload();
         }
 
+        const downloadEmail = async (messageId) => {
+            let res;
+            try {
+                res = await fetch(`/get-emlContent?messageId=${messageId}`);
+            } catch (err) {
+                showError('Couldn\'t fetch required content for download.', 'The email may have been removed from store. See the browser console for more details.')
+                console.error(err)
+                return;
+            }
+            const emlContent = await res.json();
+
+            const a = document.createElement('a');
+            a.href = makeBlob('message/rfc822', btoa(String.fromCharCode.apply(null, emlContent.body.data)));
+            a.download = `${emlContent.fileName}.eml`;
+            a.click();
+        }
+
         let theme = getTheme()
         document.documentElement.setAttribute('data-theme', theme);
 

test/getEmlContent.test.ts

@@ -0,0 +1,43 @@
+import { SES, SendEmailCommand } from '@aws-sdk/client-ses';
+import axios from 'axios';
+import { Store } from '../src/store';
+import { CreateEmlContentResult } from '../src/emlFile';
+import { baseURL } from './globals';
+
+test('can get eml content', async () => {
+  const ses = new SES({
+    endpoint: baseURL,
+    region: 'aws-ses-v2-local',
+    credentials: { accessKeyId: 'ANY_STRING', secretAccessKey: 'ANY_STRING' },
+  });
+  await ses.send(new SendEmailCommand({
+    Source: 'sender@example.com',
+    Destination: { ToAddresses: ['receiver@example.com'] },
+    Message: {
+      Subject: { Data: 'This is the subject' },
+      Body: { Text: { Data: 'This is the email contents' } },
+    },
+  }));
+  const storeWithEmails: Store = (await axios({
+    method: 'get',
+    baseURL,
+    url: '/store',
+  })).data;
+  expect(storeWithEmails.emails).toHaveLength(1);
+  const messageId = storeWithEmails.emails[0].messageId;
+
+  const c: CreateEmlContentResult = (await axios({
+    method: 'get',
+    url: `/get-emlContent?messageId=${messageId}`,
+    baseURL,
+  })).data;
+
+  expect(c).toMatchObject({
+    messageId: messageId,
+    fileName: 'This is the subject',
+    body: {
+      type: "Buffer",
+      data: expect.any(Array<String>),
+    }
+  });
+});