Feedsmith

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Strict Mode ​

By default, Feedsmith is lenient — all fields are optional to accommodate real-world feeds that may not follow specifications exactly. When strict mode is enabled, TypeScript will enforce fields that are required by the specification. This validation happens at compile time only, not at runtime.

typescript
import { generateRssFeed } from 'feedsmith'

// Lenient mode (default) - compiles fine even with missing required fields
const rss = generateRssFeed({ title: 'My Feed' })

// Strict mode - TypeScript error if required fields are missing
const rss = generateRssFeed(
  {
    title: 'My Feed',
    link: 'https://example.com',
    description: 'A complete feed'
  },
  { strict: true }
)

Enabling Strict Mode ​

Pass strict: true in the options to enable compile-time validation:

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

// RSS with strict mode
const rss = generateRssFeed(feedData, { strict: true })

// Atom with strict mode
const atom = generateAtomFeed(feedData, { strict: true })

// JSON Feed with strict mode
const json = generateJsonFeed(feedData, { strict: true })

// OPML with strict mode
const opml = generateOpml(opmlData, { strict: true })

Date Objects Required ​

In strict mode, date fields must be JavaScript Date objects, not strings:

typescript
// Lenient mode - strings work fine
generateRssFeed({
  title: 'Feed',
  link: 'https://example.com',
  description: 'Description',
  pubDate: '2024-01-01T00:00:00Z' // String dates allowed
})

// Strict mode - must use Date objects
generateRssFeed(
  {
    title: 'Feed',
    link: 'https://example.com',
    description: 'Description',
    pubDate: new Date('2024-01-01') // Date object required
  },
  { strict: true }
)

Required Fields ​

See the reference documentation for required fields in strict mode:

Some namespaces also have required fields for their nested types. Look for Requirable<...> in type definitions to identify fields that become required in strict mode.

Combining with Other Options ​

Strict mode can be combined with other generation options:

typescript
generateRssFeed(
  {
    title: 'My Feed',
    link: 'https://example.com',
    description: 'A complete feed',
    items: []
  },
  {
    strict: true,
    stylesheets: [{ type: 'text/xsl', href: '/feed.xsl' }]
  }
)

When to Use Strict Mode ​

Use strict mode when:

  • Building new feeds from scratch where you control all data
  • You want TypeScript to catch missing required fields
  • Following specifications precisely matters for your use case

Use lenient mode (default) when:

  • Processing feeds from external sources
  • Migrating existing feeds that may be incomplete