From de0fb8542a756819cda83d557c5f5c852947d599 Mon Sep 17 00:00:00 2001
From: Hongbo Wu <hongbo@omnivore.app>
Date: Thu, 20 Apr 2023 20:52:43 +0800
Subject: [PATCH] Decode email metadata from rfc2047 encoded

---
 packages/inbound-email-handler/src/index.ts   |  5 ++--
 .../inbound-email-handler/src/newsletter.ts   |  6 ++--
 .../test/newsletter.test.ts                   | 30 ++++++++++++-------
 3 files changed, 25 insertions(+), 16 deletions(-)

diff --git a/packages/inbound-email-handler/src/index.ts b/packages/inbound-email-handler/src/index.ts
index 6f88f5ff7..906943238 100644
--- a/packages/inbound-email-handler/src/index.ts
+++ b/packages/inbound-email-handler/src/index.ts
@@ -11,6 +11,7 @@ import axios from 'axios'
 import * as jwt from 'jsonwebtoken'
 import parseHeaders from 'parse-headers'
 import * as multipart from 'parse-multipart-data'
+import rfc2047 from 'rfc2047'
 import { promisify } from 'util'
 import { Attachment, handleAttachments, isAttachment } from './attachment'
 import {
@@ -96,14 +97,14 @@ export const inboundEmailHandler = Sentry.GCPFunction.wrapHttpFunction(
       for (const part of parts) {
         const { name, data, type, filename } = part
         if (name && data) {
-          parsed[name] = data.toString()
+          // decode data from rfc2047 encoded
+          parsed[name] = rfc2047.decode(data.toString())
         } else if (isAttachment(type, data)) {
           attachments.push({ data, contentType: type, filename })
         } else {
           console.log('no data or name for ', part)
         }
       }
-
       const headers = parseHeaders(parsed.headers)
       console.log('parsed: ', parsed)
       console.log('headers: ', headers)
diff --git a/packages/inbound-email-handler/src/newsletter.ts b/packages/inbound-email-handler/src/newsletter.ts
index 715a8a6b6..54be5d3dd 100644
--- a/packages/inbound-email-handler/src/newsletter.ts
+++ b/packages/inbound-email-handler/src/newsletter.ts
@@ -1,5 +1,4 @@
 import addressparser from 'addressparser'
-import rfc2047 from 'rfc2047'
 import { publishMessage } from './index'
 
 interface Unsubscribe {
@@ -19,10 +18,9 @@ const CONFIRMATION_EMAIL_SUBJECT_PATTERN =
 export const parseUnsubscribe = (unSubHeader: string): Unsubscribe => {
   // parse list-unsubscribe header
   // e.g. List-Unsubscribe: <https://omnivore.com/unsub>, <mailto:unsub@omnivore.com>
-  const decoded = rfc2047.decode(unSubHeader)
   return {
-    mailTo: decoded.match(UNSUBSCRIBE_MAIL_TO_PATTERN)?.[1],
-    httpUrl: decoded.match(UNSUBSCRIBE_HTTP_URL_PATTERN)?.[1],
+    mailTo: unSubHeader.match(UNSUBSCRIBE_MAIL_TO_PATTERN)?.[1],
+    httpUrl: unSubHeader.match(UNSUBSCRIBE_HTTP_URL_PATTERN)?.[1],
   }
 }
 
diff --git a/packages/inbound-email-handler/test/newsletter.test.ts b/packages/inbound-email-handler/test/newsletter.test.ts
index 60f96f712..b32a7f504 100644
--- a/packages/inbound-email-handler/test/newsletter.test.ts
+++ b/packages/inbound-email-handler/test/newsletter.test.ts
@@ -1,5 +1,7 @@
 import { expect } from 'chai'
 import 'mocha'
+import parseHeaders from 'parse-headers'
+import rfc2047 from 'rfc2047'
 import { parsedTo } from '../src'
 import {
   getConfirmationCode,
@@ -81,16 +83,6 @@ describe('Newsletter email test', () => {
 
       expect(parseUnsubscribe(header).httpUrl).to.equal(httpUrl)
     })
-
-    context('when unsubscribe header rfc2047 encoded', () => {
-      it('returns mail to address if exists', () => {
-        const header = `=?us-ascii?Q?=3Cmailto=3A654e9594-184c-4884-8e02-e6e58a3a6871+87e39b3d-c3ca-4be?= =?us-ascii?Q?b-ba4d-977cc2ba61e7+067a353f-f775-4f2c-?= =?us-ascii?Q?a5cc-978df38deeca=40unsub=2Ebeehiiv=2Ecom=3E=2C?= =?us-ascii?Q?_=3Chttps=3A=2F=2Fwww=2Emilkroad=2Ecom=2Fsubscribe=2F87e39b3d-c3ca-4beb-ba4d-97?= =?us-ascii?Q?7cc2ba61e7=2Fmanage=3Fpost=5Fid=3D067a353f-f775?= =?us-ascii?Q?-4f2c-a5cc-978df38deeca=3E?=',`
-
-        expect(parseUnsubscribe(header).mailTo).to.equal(
-          '654e9594-184c-4884-8e02-e6e58a3a6871+87e39b3d-c3ca-4beb-ba4d-977cc2ba61e7+067a353f-f775-4f2c-a5cc-978df38deeca@unsub.beehiiv.com'
-        )
-      })
-    })
   })
 })
 
@@ -128,3 +120,21 @@ describe('isSubscriptionConfirmationEmail', () => {
     expect(isSubscriptionConfirmationEmail(subject)).to.be.true
   })
 })
+
+describe('decode and parse headers', () => {
+  it('decodes headers from rfc2047 and parses it', () => {
+    const headerStr =
+      'Subject: =?UTF-8?B?8J+MjQ==?= Dead on arrival\n' +
+      'x-newsletter: =?us-ascii?Q?https=3A=2F=2Farchives=2Einternationalintrigue=2Eio=2Fp=2Fsudan-ceasefires-c?= =?us-ascii?Q?ollapse-fighting-intensifies?=\n'
+    const decoded = rfc2047.decode(headerStr)
+    expect(decoded).to.eql(
+      'Subject: 🌍 Dead on arrival\n' +
+        'x-newsletter: https://archives.internationalintrigue.io/p/sudan-ceasefires-collapse-fighting-intensifies\n'
+    )
+    expect(parseHeaders(decoded)).to.eql({
+      subject: '🌍 Dead on arrival',
+      'x-newsletter':
+        'https://archives.internationalintrigue.io/p/sudan-ceasefires-collapse-fighting-intensifies',
+    })
+  })
+})