Migration from 1.x to 2.x

This guide covers all breaking changes and new features when upgrading from Feedsmith 1.x to 2.x. Each breaking change is detailed with specific upgrade steps and examples.

IMPORTANT

Version 2.x introduces significant improvements including enhanced type safety, comprehensive feed generation support, and better namespace handling. However, it includes several breaking changes that require code updates.

Installation

Update your package to the latest 2.x version:

npm install feedsmith@latest

Breaking Changes

parseFeed Return Type Property Rename

The parseFeed function now returns format instead of type to better align with industry terminology.

Before (1.x)

import { parseFeed } from 'feedsmith'

const result = parseFeed(feedContent)
console.log(result.type) // rss, atom, json, rdf

After (2.x)

import { parseFeed } from 'feedsmith'

const result = parseFeed(feedContent)
console.log(result.format) // rss, atom, json, rdf

Migration Steps

1. Replace all instances of result.type with result.format

RSS GUID Structure Change

RSS feed item GUIDs are now structured objects instead of plain strings to properly handle the isPermaLink attribute.

Before (1.x)

const rssFeed = parseRssFeed(content)
const guid = rssFeed.items?.[0]?.guid // string

After (2.x)

const rssFeed = parseRssFeed(content)
const guid = rssFeed.items?.[0]?.guid?.value // string
const isPermaLink = rssFeed.items?.[0]?.guid?.isPermaLink // boolean | undefined

Migration Steps

1. Replace item.guid with item.guid?.value when accessing the GUID string
2. Use item.guid?.isPermaLink to check if the GUID is a permalink

Podcast Namespace contentLink Casing

The contentlink elements in the Podcast namespace are now properly cased as contentLink.

Before (1.x)

const contentLinks = feed.podcast?.contentlink // lowercase

After (2.x)

const contentLinks = feed.podcast?.contentLink // camelCase

Migration Steps

1. Update access to podcast content links from contentlink to contentLink
2. This affects RSS feeds using the Podcast namespace

Enhanced Type System

The type system has been significantly enhanced with generic types and stricter type safety.

Before (1.x)

// Simple type definitions
interface RssFeed {
  title: string
  items: RssItem[]
}

After (2.x)

// Generic type system with DateLike parameter
type RssFeed<TDate extends DateLike = string> = DeepPartial<{
  title: string
  items: RssItem<TDate>[]
  // All fields are now optional at type level
}>

Migration Steps

1. All feed properties are now properly typed as optional, reflecting real-world feed variability
2. Use optional chaining (?.) when accessing feed properties
3. Consider using type guards for critical properties
4. The enhanced typing may reveal previously hidden bugs in your code

RSS Enclosure Structure Change

RSS feed items now support multiple enclosures as an array instead of a single enclosure object.

Before (1.x)

const rssFeed = parseRssFeed(content)
const enclosure = rssFeed.items?.[0]?.enclosure // single Enclosure object
if (enclosure) {
  console.log(enclosure.url)
  console.log(enclosure.type)
  console.log(enclosure.length)
}

After (2.x)

const rssFeed = parseRssFeed(content)
const enclosures = rssFeed.items?.[0]?.enclosures // Array<Enclosure>
if (enclosures?.length) {
  console.log(enclosures[0].url)
  console.log(enclosures[0].type)
  console.log(enclosures[0].length)
}

Migration Steps

1. Replace item.enclosure with item.enclosures?.[0] for single enclosure access
2. Update code to handle multiple enclosures by iterating over the enclosures array
3. Check for array length instead of truthy enclosure object

New Features

Comprehensive Feed Generation

Version 2.x introduces complete feed generation support:

import {
  generateRssFeed,
  generateAtomFeed,
  generateJsonFeed,
  generateOpml
} from 'feedsmith'

// Generate RSS feed
const rss = generateRssFeed({
  title: 'My Blog',
  link: 'https://example.com',
  description: 'A blog about development',
  items: [/* items */]
})

// Generate Atom feed
const atom = generateAtomFeed({
  id: 'https://example.com/feed',
  title: 'My Blog',
  updated: new Date(),
  entries: [/* entries */]
})

Stylesheet Support

Add stylesheets to generated XML feeds:

const rss = generateRssFeed(feedData, {
  stylesheets: [{
    type: 'text/xsl',
    href: '/feed.xsl'
  }]
})

Enhanced Namespace Support

New namespaces have been added:

• Dublin Core Terms (dcterms): Extended metadata support
• Well-Formed Web (wfw): Comment API support
• YouTube (yt): YouTube-specific extensions

// Access new namespace data
const feed = parseRssFeed(content)
console.log(feed.dcterms?.created)
console.log(feed.wfw?.commentRss)
console.log(feed.yt?.channelId)

Automatic Namespace Normalization

Custom namespace prefixes are automatically normalized to standard ones:

// Input: <custom:creator>John Doe</custom:creator>
// Automatically becomes: feed.dc.creator

Migration Checklist

Use this checklist to ensure a complete migration:

• Update result.type to result.format in all parseFeed calls
• Change item.guid to item.guid?.value for RSS feeds
• Change item.enclosure to item.enclosures?.[0] for RSS feeds
• Change podcast.contentlink to podcast.contentLink
• Add optional chaining (?.) for all feed property access
• Test with your existing feeds to ensure proper parsing
• Consider utilizing new generation features
• Explore enhanced namespace support for richer data access