Improved Filesystem Observer with Accurate Date Created Handling

Summary

Enhanced the filesystem observer in the tidyverse submodule to accurately determine and preserve file creation dates using file birthtime, ensuring frontmatter metadata integrity across all content files.

Why Care

Accurate date_created values are critical for content chronology and historical tracking. This improvement ensures we maintain the earliest known creation date for each file, preventing data loss when files are modified or processed by the observer system.

Implementation

Changes Made

  • Updated the date_created handling logic in the filesystem observer to use file birthtime instead of modification time
  • Added special comparison logic to keep the earlier of existing date_created or file birthtime
  • Improved error handling to prevent fallbacks to current date when file stats can't be determined
  • Enhanced logging to track date comparison decisions

Files Modified:

  • /tidyverse/observers/templates/tooling.ts: Updated template defaultValueFn for date_created
  • /tidyverse/observers/fileSystemObserver.ts: Added special handling for date_created field

Technical Details

Template Default Value Function

typescript 
// Path: /tidyverse/observers/templates/tooling.ts
date_created: {
  type: 'date',
  description: 'Creation date',
  defaultValueFn: (filePath: string) => {
    try {
      console.log(`Generating date_created for ${filePath}`);
      
      // Use the Node.js fs module for synchronous operations
      const fs = require('fs');
      
      // Check if file exists
      if (fs.existsSync(filePath)) {
        // Get file stats to access creation time
        const stats = fs.statSync(filePath);
        
        // Use birthtime (actual file creation time) which is reliable on Mac
        const timestamp = stats.birthtime;
        
        console.log(`File creation time for ${filePath}: ${timestamp.toISOString()}`);
        
        // Return full ISO string with timezone
        return timestamp.toISOString();
      } else {
        console.log(`File does not exist: ${filePath}`);
        // Return null instead of current date
        return null;
      }
    } catch (error) {
      console.error(`Error getting file stats for ${filePath}:`, error);
      // Return null instead of current date
      return null;
    }
  }
}

Special Field Handling in Observer

typescript 
// Path: /tidyverse/observers/fileSystemObserver.ts
// Special handling for date_created - compare with file birthtime
if (key === 'date_created') {
  try {
    // Get file birthtime
    const fs = require('fs');
    if (fs.existsSync(filePath)) {
      const stats = fs.statSync(filePath);
      const birthtime = stats.birthtime;
      const birthtimeIso = birthtime.toISOString();
      
      // If date_created exists, check if birthtime is earlier
      if (updatedFrontmatter[key]) {
        const existingDate = new Date(updatedFrontmatter[key]);
        
        // If birthtime is earlier than the existing date_created, update it
        if (birthtime < existingDate) {
          console.log(`Updating date_created for ${filePath} from ${updatedFrontmatter[key]} to ${birthtimeIso} (file birthtime is earlier)`);
          updatedFrontmatter[key] = birthtimeIso;
          changed = true;
        } else {
          console.log(`Keeping existing date_created for ${filePath}: ${updatedFrontmatter[key]} (earlier than file birthtime ${birthtimeIso})`);
        }
      } 
      // If date_created doesn't exist, add it
      else {
        console.log(`Adding date_created for ${filePath}: ${birthtimeIso}`);
        updatedFrontmatter[key] = birthtimeIso;
        changed = true;
      }
      
      // Skip the standard field processing for date_created
      continue;
    }
  } catch (error) {
    console.error(`Error handling date_created for ${filePath}:`, error);
    // Continue with standard processing if there was an error
  }
}

Integration Points

  • The observer system integrates with the Astro build process by ensuring all content files have consistent and accurate frontmatter
  • The date_created field is used by various components in the site to display chronological information
  • This implementation works with the existing template registry system to validate and update frontmatter

Documentation

  • Updated the filesystem observer prompt to reflect the current implementation: /content/lost-in-public/prompts/data-integrity/Use-Filesystem-Observer-to-Assert-Frontmatter-Updated.md
  • The observer logs detailed information about date handling decisions to the console, which can be used for debugging and verification
  • Testing confirmed that the birthtime property is reliable on the Mac system used for development