From 400d132612b9f6f3c928073e6c9fba3690f73788 Mon Sep 17 00:00:00 2001
From: fiatjaf <fiatjaf@gmail.com>
Date: Fri, 21 Nov 2025 19:51:55 -0300
Subject: [PATCH] nip77: negentropy tests and small fixes.

---
 nip77.test.ts | 114 ++++++++++++++++++++++++++++++++++++++++++++++++++
 nip77.ts      |  12 ++++--
 2 files changed, 122 insertions(+), 4 deletions(-)
 create mode 100644 nip77.test.ts

diff --git a/nip77.test.ts b/nip77.test.ts
new file mode 100644
index 0000000..8693036
--- /dev/null
+++ b/nip77.test.ts
@@ -0,0 +1,114 @@
+import { describe, test, expect } from 'bun:test'
+import { NegentropySync, NegentropyStorageVector } from './nip77.ts'
+import { Relay } from './relay.ts'
+import { NostrEvent } from './core.ts'
+
+// const RELAY = 'ws://127.0.0.1:10547'
+const RELAY = 'wss://relay.damus.io'
+
+describe('NegentropySync', () => {
+  test('syncs events from ' + RELAY, async () => {
+    const relay = await Relay.connect(RELAY)
+
+    const storage = new NegentropyStorageVector()
+    storage.seal()
+    const filter = {
+      authors: ['3bf0c63fcb93463407af97a5e5ee64fa883d107ef9e558472c4eb9aaaefa459d'],
+      kinds: [30617, 30618],
+    }
+
+    let ids1: string[] = []
+    const done1 = Promise.withResolvers<void>()
+    const sync1 = new NegentropySync(relay, storage, filter, {
+      onneed: (id: string) => {
+        ids1.push(id)
+      },
+      onclose: err => {
+        expect(err).toBeUndefined()
+        done1.resolve()
+      },
+    })
+
+    await sync1.start()
+    await done1.promise
+
+    expect(ids1.length).toBeGreaterThan(10)
+
+    sync1.close()
+
+    // fetch events
+    const events1: NostrEvent[] = []
+    const fetched = Promise.withResolvers()
+    const sub = relay.subscribe([{ ids: ids1 }], {
+      onevent(evt) {
+        events1.push(evt)
+      },
+      oneose() {
+        sub.close()
+        fetched.resolve()
+      },
+    })
+    await fetched.promise
+    expect(events1.map(evt => evt.id).sort()).toEqual(ids1.sort())
+
+    // Second sync with local events
+    await relay.connect()
+
+    const storage2 = new NegentropyStorageVector()
+    for (const evt of events1) {
+      storage2.insert(evt.created_at, evt.id)
+    }
+    storage2.seal()
+
+    let ids2: string[] = []
+    let done2 = Promise.withResolvers()
+    const sync2 = new NegentropySync(relay, storage2, filter, {
+      onneed: (id: string) => {
+        ids2.push(id)
+      },
+      onclose: err => {
+        expect(err).toBeUndefined()
+        done2.resolve()
+      },
+    })
+
+    await sync2.start()
+    await done2.promise
+
+    expect(ids2.length).toBe(0)
+
+    sync2.close()
+
+    // third sync with 4 events removed
+    const storage3 = new NegentropyStorageVector()
+
+    // shuffle
+    ids1.sort(() => Math.random() - 0.5)
+    const removedEvents = ids1.slice(0, 1 + Math.floor(Math.random() * ids1.length - 1))
+    for (const evt of events1) {
+      if (!removedEvents.includes(evt.id)) {
+        storage3.insert(evt.created_at, evt.id)
+      }
+    }
+    storage3.seal()
+
+    let ids3: string[] = []
+    const done3 = Promise.withResolvers()
+    const sync3 = new NegentropySync(relay, storage3, filter, {
+      onneed: (id: string) => {
+        ids3.push(id)
+      },
+      onclose: err => {
+        expect(err).toBeUndefined()
+        done3.resolve()
+      },
+    })
+
+    await sync3.start()
+    await done3.promise
+
+    expect(ids3.sort()).toEqual(removedEvents.sort())
+
+    sync3.close()
+  })
+})
diff --git a/nip77.ts b/nip77.ts
index a2abdb5..fb0ae6f 100644
--- a/nip77.ts
+++ b/nip77.ts
@@ -537,6 +537,7 @@ export class NegentropySync {
   relay: AbstractRelay
   storage: NegentropyStorageVector
   private neg: Negentropy
+  private filter: Filter
   private subscription: Subscription
   private onhave?: (id: string) => void
   private onneed?: (id: string) => void
@@ -557,8 +558,10 @@ export class NegentropySync {
     this.neg = new Negentropy(storage)
     this.onhave = params.onhave
     this.onneed = params.onneed
+    this.filter = filter
 
-    this.subscription = this.relay.prepareSubscription([filter], { label: params.label || 'negentropy' })
+    // we prepare a subscription with an empty filter, but it will not be used
+    this.subscription = this.relay.prepareSubscription([{}], { label: params.label || 'negentropy' })
     this.subscription.oncustom = (data: string[]) => {
       switch (data[0]) {
         case 'NEG-MSG': {
@@ -569,6 +572,9 @@ export class NegentropySync {
             const response = this.neg.reconcile(data[2], this.onhave, this.onneed)
             if (response) {
               this.relay.send(`["NEG-MSG", "${this.subscription.id}", "${response}"]`)
+            } else {
+              this.close()
+              params.onclose?.()
             }
           } catch (error) {
             console.error('negentropy reconcile error:', error)
@@ -591,9 +597,7 @@ export class NegentropySync {
 
   async start(): Promise<void> {
     const initMsg = this.neg.initiate()
-    if (initMsg) {
-      this.relay.send(`["NEG-OPEN","${this.subscription.id}",${initMsg}]`)
-    }
+    this.relay.send(`["NEG-OPEN","${this.subscription.id}",${JSON.stringify(this.filter)},"${initMsg}"]`)
   }
 
   close(): void {