AI Newsletter Digest improvements: fixed QP soft line break decoding, URL extraction, and content cleaning

archive/inactive-skills/evolver/src/gep/contentHash.js

@@ -0,0 +1,65 @@
+// Content-addressable hashing for GEP assets.
+// Provides canonical JSON serialization and SHA-256 based asset IDs.
+// This enables deduplication, tamper detection, and cross-node consistency.
+
+const crypto = require('crypto');
+
+// Schema version for all GEP asset types.
+// Bump MINOR for additive fields; MAJOR for breaking changes.
+const SCHEMA_VERSION = '1.5.0';
+
+// Canonical JSON: deterministic serialization with sorted keys at all levels.
+// Arrays preserve order; non-finite numbers become null; undefined becomes null.
+function canonicalize(obj) {
+  if (obj === null || obj === undefined) return 'null';
+  if (typeof obj === 'boolean') return obj ? 'true' : 'false';
+  if (typeof obj === 'number') {
+    if (!Number.isFinite(obj)) return 'null';
+    return String(obj);
+  }
+  if (typeof obj === 'string') return JSON.stringify(obj);
+  if (Array.isArray(obj)) {
+    return '[' + obj.map(canonicalize).join(',') + ']';
+  }
+  if (typeof obj === 'object') {
+    const keys = Object.keys(obj).sort();
+    const pairs = [];
+    for (const k of keys) {
+      pairs.push(JSON.stringify(k) + ':' + canonicalize(obj[k]));
+    }
+    return '{' + pairs.join(',') + '}';
+  }
+  return 'null';
+}
+
+// Compute a content-addressable asset ID.
+// Excludes self-referential fields (asset_id itself) from the hash input.
+// Returns "sha256:<hex>".
+function computeAssetId(obj, excludeFields) {
+  if (!obj || typeof obj !== 'object') return null;
+  const exclude = new Set(Array.isArray(excludeFields) ? excludeFields : ['asset_id']);
+  const clean = {};
+  for (const k of Object.keys(obj)) {
+    if (exclude.has(k)) continue;
+    clean[k] = obj[k];
+  }
+  const canonical = canonicalize(clean);
+  const hash = crypto.createHash('sha256').update(canonical, 'utf8').digest('hex');
+  return 'sha256:' + hash;
+}
+
+// Verify that an object's asset_id matches its content.
+function verifyAssetId(obj) {
+  if (!obj || typeof obj !== 'object') return false;
+  const claimed = obj.asset_id;
+  if (!claimed || typeof claimed !== 'string') return false;
+  const computed = computeAssetId(obj);
+  return claimed === computed;
+}
+
+module.exports = {
+  SCHEMA_VERSION,
+  canonicalize,
+  computeAssetId,
+  verifyAssetId,
+};