beacon: real-data compat with imported nostr-beacon dump

Surfaced by importing the 2.5GB prod nostr-beacon DB locally and pointing
beacon at it:

- db.js: tolerate a pre-existing pubkey index. The prod dump ships a *unique*
  pubkey_1; our createIndex({pubkey:1}) then fails with IndexKeySpecsConflict
  (code 86) and crashed boot. Ignore that one code — the index already serves.
- diddoc.js: accept both follows shapes. Our indexer writes the raw kind-3
  event ({tags:[["p",hex]]}); the prod 'follows' collection stores a derived
  shape ({follows:[hex,...], count}). Build did:nostr follows from either.
- test: regression for the derived {follows:[...]} shape (8/8 pass).

Author: melvincarvalho

src/db.js

@@ -26,9 +26,16 @@ export async function connect() {
   client = new MongoClient(uri);
   await client.connect();
   db = client.db(dbName);
-  // non-unique index for query/dedupe perf — does not change the doc shape
+  // pubkey index for query/dedupe perf — does not change the doc shape.
+  // Tolerate a pre-existing index (e.g. an imported nostr-beacon dump already
+  // carries a *unique* pubkey_1); a spec conflict (code 86) just means it's
+  // already there and serving lookups, so it is safe to ignore.
   for (const name of new Set(Object.values(COLLECTIONS))) {
-    await db.collection(name).createIndex({ pubkey: 1 });
+    try {
+      await db.collection(name).createIndex({ pubkey: 1 });
+    } catch (e) {
+      if (e?.code !== 86) throw e;
+    }
   }
   return db;
 }

src/diddoc.js

@@ -45,13 +45,19 @@ export function buildDidDocument(pubkey, { profile, follows, relays } = {}) {
     } catch { /* malformed kind-0 content */ }
   }
 
-  // kind 3 -> follows (did:nostr of each p-tag)
+  // kind 3 -> follows (did:nostr of each followed key). Accept both the raw
+  // kind-3 event ({tags:[["p",hex],…]}, what our indexer writes) and the
+  // derived nostr-beacon shape ({follows:[hex,…], count}, from an imported dump).
+  let followHexes = [];
   if (Array.isArray(follows?.tags)) {
-    const f = follows.tags
-      .filter((t) => t[0] === 'p' && HEX64.test(String(t[1]).toLowerCase()))
-      .map((t) => `did:nostr:${String(t[1]).toLowerCase()}`);
-    if (f.length) doc.follows = f;
+    followHexes = follows.tags.filter((t) => t[0] === 'p').map((t) => t[1]);
+  } else if (Array.isArray(follows?.follows)) {
+    followHexes = follows.follows;
   }
+  const f = followHexes
+    .filter((h) => HEX64.test(String(h).toLowerCase()))
+    .map((h) => `did:nostr:${String(h).toLowerCase()}`);
+  if (f.length) doc.follows = f;
 
   // kind 10002 -> service (Relay)
   if (Array.isArray(relays?.tags)) {

test/diddoc.test.js

@@ -32,6 +32,12 @@ test('enhanced: profile (kind 0), follows (kind 3), service (kind 10002)', () =>
   assert.equal(d.service[0].serviceEndpoint, 'wss://relay.example/');
 });
 
+test('follows: derived nostr-beacon shape ({follows:[hex,…]}) also resolves', () => {
+  const a = 'a'.repeat(64), b = 'b'.repeat(64);
+  const d = buildDidDocument(PK, { follows: { follows: [a, b], count: 2 } });
+  assert.deepEqual(d.follows, [`did:nostr:${a}`, `did:nostr:${b}`]);
+});
+
 test('rejects a non-hex (e.g. npub) identifier', () => {
   assert.equal(buildDidDocument('npub1xxx'), null);
   assert.equal(buildDidDocument(''), null);