feat: map Enclosure.title to JSON Feed attachment title

src/formats/atom/atom.conformance.test.ts

@@ -390,4 +390,24 @@ describe('Atom enclosure mapping (RFC 4287 §4.2.7.2)', () => {
     )
     expect(xml).not.toContain('1800')
   })
+
+  it('ignores enclosure.title (JSON Feed-only attachment field, no Atom mapping)', () => {
+    const xml = toAtom({
+      ...withEnclosure,
+      items: [
+        {
+          ...withEnclosure.items[0],
+          enclosure: {
+            url: 'https://example.com/ep1.mp3',
+            type: 'audio/mpeg',
+            title: 'Episode 1',
+          },
+        },
+      ],
+    })
+    expect(xml).toContain(
+      '<link rel="enclosure" href="https://example.com/ep1.mp3" type="audio/mpeg"/>',
+    )
+    expect(xml).not.toContain('Episode 1')
+  })
 })

src/formats/json/index.ts

@@ -106,6 +106,7 @@ function jsonItem(item: FeedItem, v1: boolean, base?: string): Record<string, un
     }
     if (enclosure.length !== undefined) attachment.size_in_bytes = enclosure.length
     if (enclosure.duration !== undefined) attachment.duration_in_seconds = enclosure.duration
+    if (enclosure.title) attachment.title = enclosure.title
     return attachment
   })
   if (attachments.length) o.attachments = attachments

src/formats/json/json.test.ts

@@ -454,6 +454,44 @@ describe('toJSONFeed', () => {
     expect(json.items[0].attachments[0].duration_in_seconds).toBeUndefined()
   })
 
+  it('maps enclosure.title to the attachment title', () => {
+    const json = JSON.parse(
+      toJSONFeed({
+        options: { title: 't', link: 'https://example.com/' },
+        items: [
+          {
+            title: 'a',
+            link: 'https://example.com/1',
+            content: '<p>b</p>',
+            enclosure: {
+              url: 'https://example.com/a.mp3',
+              type: 'audio/mpeg',
+              title: 'Episode 1',
+            },
+          },
+        ],
+      }),
+    )
+    expect(json.items[0].attachments[0].title).toBe('Episode 1')
+  })
+
+  it('omits the attachment title when the enclosure has no title', () => {
+    const json = JSON.parse(
+      toJSONFeed({
+        options: { title: 't', link: 'https://example.com/' },
+        items: [
+          {
+            title: 'a',
+            link: 'https://example.com/1',
+            content: '<p>b</p>',
+            enclosure: { url: 'https://example.com/a.mp3', type: 'audio/mpeg' },
+          },
+        ],
+      }),
+    )
+    expect(json.items[0].attachments[0].title).toBeUndefined()
+  })
+
   it('pretty-prints with 2-space indentation', () => {
     const out = toJSONFeed(
       { options: { title: 't', link: 'https://example.com/' }, items: [] },

src/types.ts

@@ -48,6 +48,8 @@ export interface Enclosure {
   length?: number
   /** Duration in seconds. JSON Feed `duration_in_seconds`; no RSS/Atom enclosure equivalent. */
   duration?: number
+  /** Attachment name. JSON Feed `title`; Atom link `title`; no RSS equivalent. */
+  title?: string
 }
 
 /** `itunes:owner` — the podcast's admin contact, shown only to Apple Podcasts, never in the UI. */