Schema.org markup passes basic validity checks

A JSON syntax error in any <script type="application/ld+json"> block silently discards the entire schema — Google logs a parse failure and ignores the block, removing that page from Rich Results eligibility. Beyond syntax, schema-org Article and schema-org WebSite define required properties that must be present for Google to trust and surface the markup: an Article missing datePublished will not appear in Top Stories carousels regardless of content quality. Invalid structured data is equivalent to no structured data from Google's perspective, making this a direct ranking signal failure.

Lint all JSON-LD before embedding. The fastest fix is running each block through JSON.parse() in a build-time script or using the Google Rich Results Test against your staging URL. For BlogPosting, the required fields are headline, author (with @type: "Person" and name), datePublished, and image. For WebSite, the minimum is name and url.

Add a validation step in src/lib/schema.ts that asserts required fields at build time:

// src/lib/schema.ts
export function buildArticleSchema(post: Post) {
  if (!post.title || !post.publishedAt || !post.authorName) {
    throw new Error(`Article schema: missing required fields for "${post.slug}"`);
  }
  return {
    '@context': 'https://schema.org',
    '@type': 'BlogPosting',
    headline: post.title,
    datePublished: post.publishedAt,
    author: { '@type': 'Person', name: post.authorName },
  };
}

This catches missing properties at build time rather than silently shipping invalid schema to production.