Support hierarchical mime part content parsing

index.js

@@ -18,6 +18,7 @@
  * @property {string} encoding Content-Transfer-Encoding
  * @property {string} Body Encoded content
  * @property {Array<string>} Headers Encoded headers
+ * @property {MIME} MIME Mime property
  */
 
 /**
@@ -39,6 +40,7 @@
  * @property {Date} date Mail Date header
  * @property {Date} deliveryDate Mail Delivery-Date header
  * @property {Array<Attachment>} attachments List of mail attachments
+ * @property {Attachment} Content The main mail content
  * @property {string} Created Mail Created property
  * @property {MIME} MIME Mail Mime property
  */
@@ -173,6 +175,25 @@ function decode(str, encoding, charset) {
   return require('iconv-lite').decode(buffer, charset)
 }
 
+/**
+ * Recursively gathers the attachments of both the passed mail object
+ * and recursively of its attachment parts.
+ *
+ * @param {object} entry MailHog mail or Attachment object
+ * @returns {Array<Attachment>} List of mail attachments parts
+ */
+function getMimePartsRecursively(entry) {
+  if (!entry.MIME) {
+    return []
+  }
+  let results = []
+  for (const part of entry.MIME.Parts) {
+    results.push(part)
+    results = results.concat(getMimePartsRecursively(part))
+  }
+  return results
+}
+
 /**
  * Returns the content part matching the given content-type regular expression.
  *
@@ -182,7 +203,7 @@ function decode(str, encoding, charset) {
  */
 function getContent(mail, typeRegExp) {
   let parts = [mail.Content]
-  if (mail.MIME) parts = parts.concat(mail.MIME.Parts)
+  parts = parts.concat(getMimePartsRecursively(mail))
   for (const part of parts) {
     const type = (part.Headers['Content-Type'] || '').toString()
     if (typeRegExp.test(type)) {

index.test.js

@@ -219,6 +219,26 @@ describe('multipart', function () {
   })
 })
 
+describe('multipart hierarchical', function () {
+  it('parses quoted-printable encoded text content', async function () {
+    const result = await mailhog.latestTo('[email protected]')
+    assert.strictEqual(
+      result.text,
+      'Some Test Message Text',
+      'Parses sub-level text part'
+    )
+  })
+
+  it('parses quoted-printable encoded HTML content', async function () {
+    const result = await mailhog.latestTo('[email protected]')
+    assert.strictEqual(
+      result.html,
+      'Some Test Message HTML',
+      'Parses sub-level html part'
+    )
+  })
+})
+
 describe('charset', function () {
   it('parses mail with utf8 charset', async function () {
     const result = await mailhog.latestTo('[email protected]')
@@ -297,31 +317,36 @@ describe('headers', function () {
 describe('messages', function () {
   it('retrieve mails', async function () {
     const result = await mailhog.messages()
-    assert.strictEqual(result.count, 4, 'Returns all emails')
+    assert.strictEqual(result.count, 5, 'Returns all emails')
     assert.strictEqual(
       result.items[0].subject,
+      'Mail with hierarchical mime content',
+      'Returns the decoded mail Subject header for the fifth mail in the set'
+    )
+    assert.strictEqual(
+      result.items[1].subject,
       'Mail without charset',
       'Returns the decoded mail Subject header for the first mail in the set'
     )
     assert.strictEqual(
-      result.items[1].subject,
+      result.items[2].subject,
       'ISO-8859-1',
       'Returns the decoded mail Subject header for the second mail in the set'
     )
     assert.strictEqual(
-      result.items[2].subject,
+      result.items[3].subject,
       '日本',
       'Returns the decoded mail Subject header for the third mail in the set'
     )
     assert.strictEqual(
-      result.items[3].subject,
+      result.items[4].subject,
       'üäö',
       'Returns the decoded mail Subject header for the fourth mail in the set'
     )
   })
 
   it('limit the messages range', async function () {
-    const result = await mailhog.messages(3, 1)
+    const result = await mailhog.messages(4, 1)
     assert.strictEqual(result.count, 1, 'Returns a set for the given range')
     assert.strictEqual(
       result.items[0].subject,
@@ -469,7 +494,7 @@ describe('releaseMessage', function () {
     const listResult = await mailhog.messages()
     assert.strictEqual(
       listResult.count,
-      5,
+      6,
       'Number of mails stored has increased by 1'
     )
   })
@@ -496,7 +521,7 @@ describe('deleteMessage', function () {
     const listResult = await mailhog.messages()
     assert.strictEqual(
       listResult.count,
-      3,
+      4,
       'Number of mails stored has decreased by 1'
     )
   })

mail/05.eml

@@ -0,0 +1,33 @@
+Content-Type: multipart/mixed; boundary="===============7426108140616550474=="
+Date: Tue, 17 May 2022 11:12:22 +0000
+From: [email protected]
+MIME-Version: 1.0
+Message-ID: <165278594245.265.1843128869165443175@09814d7d4841>
+Received: from [123.4.5.6] by mailhog.example (MailHog)
+          id [email protected]; Tue, 17 May 2022 11:12:22 +0000
+Return-Path: <[email protected]>
+Subject: Mail with hierarchical mime content
+To: [email protected]
+
+--===============7426108140616550474==
+Content-Type: multipart/alternative;
+ boundary="===============1607218409922029753=="
+MIME-Version: 1.0
+
+--===============1607218409922029753==
+Content-Type: text/plain; charset="utf-8"
+MIME-Version: 1.0
+Content-Transfer-Encoding: 7bit
+
+Some Test Message Text
+
+--===============1607218409922029753==
+Content-Type: text/html; charset="utf-8"
+MIME-Version: 1.0
+Content-Transfer-Encoding: 8bit
+
+Some Test Message HTML
+
+--===============1607218409922029753==--
+
+--===============7426108140616550474==--