Blog Pipeline Test Article

This article serves as a comprehensive test of the LocalJSON blog generation pipeline. It exercises every component of the system: frontmatter parsing, Markdown-to-HTML conversion, internal link resolution, JSON-LD Article schema generation, template rendering, blog index generation, sitemap updates, and acceptance validation. The pipeline is designed to be zero-dependency, using only Node.js built-in modules, making it lightweight and reliable for static site generation on Vercel.

Visit the LocalJSON homepage to see the main tool in action.

Frontmatter Validation

The pipeline requires seven mandatory frontmatter fields:

• slug — URL-friendly identifier (lowercase, hyphens only)
• title — Display title (20-70 characters recommended)
• description — SEO meta description (100-170 characters)
• date — Publication date in ISO format (YYYY-MM-DD)
• author — Author name
• cluster — Semantic category for grouping
• keywords — Array of relevant search terms

If any field is missing, the generator fails with a clear error message and writes no partial output. This fail-fast behavior prevents malformed articles from reaching production. The validation happens before any HTML is generated, ensuring that only complete, well-formed articles enter the pipeline.

Markdown Feature Coverage

The built-in Markdown parser handles the following constructs:

Headings

Heading Level 1

Heading Level 2

Heading Level 3

Paragraphs and Text Formatting

Regular paragraphs are separated by blank lines. Bold text uses double asterisks. Italic text uses single asterisks. Inline code uses backticks. You can also combine formatting like *bold italic code*. The parser correctly handles nested formatting and edge cases.

Lists

Unordered list example:

• First item with some bold text
• Second item with italic text
• Third item with inline code
• Nested list:

- Nested item one - Nested item two

Ordered list example:

1. First step
2. Second step
3. Third step

Code Blocks

Fenced code blocks with language hints:

function formatJSON(input) {
    try {
        const parsed = JSON.parse(input);
        return JSON.stringify(parsed, null, 2);
    } catch (e) {
        return 'Invalid JSON: ' + e.message;
    }
}

def validate_json_schema(data, schema):
    """Validate JSON against a JSON Schema."""
    import jsonschema
    try:
        jsonschema.validate(instance=data, schema=schema)
        return True, None
    except jsonschema.ValidationError as e:
        return False, str(e)
}

Blockquotes

The best way to predict the future is to invent it.

— Alan Kay

Links and Images

External link: LocalJSON Tool

Internal link using the pipeline's custom syntax: json-formatter-online will link to the JSON Formatter Online article (once it exists).

Image placeholder: !LocalJSON Logo

Horizontal Rule

Internal Link System

The pipeline supports Wikipedia-style internal links:

• slug — links to /blog/slug/ using the target article's title as link text
• slug|custom text — links with custom anchor text

Examples:

• json-validator → links to JSON Validator article
• json-to-csv|convert JSON to CSV → custom anchor text

If the target slug doesn't exist, a warning is printed but the build continues — the link renders as plain text rather than breaking the build. This graceful degradation ensures that the pipeline never fails due to forward references or future articles.

JSON-LD Article Schema

Every generated article page includes a JSON-LD Article schema in the . This structured data helps search engines understand the content:

• @type: Article
• headline — article title
• description — meta description
• datePublished — publication date
• author — Person with name
• publisher — Organization (LocalJSON)
• mainEntityOfPage — canonical URL
• keywords — comma-separated keywords

The schema is generated automatically from frontmatter, ensuring consistency across all articles.

Template Features

The article template (blog/template.html) mirrors the visual style of index.html:

• Same dark theme with CSS custom properties
• Sticky header with logo and language switcher (EN/ES)
• Breadcrumb navigation: Home / Blog / Article Title
• Article card with meta information (date, cluster)
• "← Back to all posts" links at top and bottom
• Footer with navigation links
• Open Graph and Twitter Card meta tags
• Self-referential canonical URL
• hreflang attributes (en, es, x-default)

The template is a single HTML file with embedded CSS, following the project's single-file philosophy. No external stylesheets or build tools are required.

Blog Index Page

Running the generator also produces blog/index.html — a listing of all articles sorted by date (newest first). Each entry shows:

• Article title (linked)
• Description
• Publication date
• Cluster tag
• "Read →" link

The index page includes JSON-LD Blog and BlogPosting structured data for the collection, helping search engines discover and index all articles efficiently.

Sitemap Integration

The generator updates sitemap.xml automatically:

• Preserves existing non-blog URLs
• Adds /blog/ index page
• Adds each article at /blog//
• Includes hreflang annotations for main pages
• Sets appropriate changefreq and priority values

The sitemap parser preserves existing lastmod, changefreq, and priority values for non-blog URLs, ensuring that manual sitemap entries are never overwritten.

Acceptance Criteria

The acceptance/blog-check.mjs validator verifies each article:

1. ✅