From 09a3713471944cac0d6f2872e313b52d4db37a2a Mon Sep 17 00:00:00 2001
From: hasundue <hasundue@gmail.com>
Date: Wed, 4 Oct 2023 07:47:04 +0900
Subject: [PATCH] feat(relay): respond to EVENT messages with OK messages

---
 client.ts           |  3 +--
 deno.json           |  2 +-
 relay.ts            | 44 +++++++++++++++++++++++++++++---------------
 tests/relay_test.ts | 17 ++++++++++++++---
 4 files changed, 45 insertions(+), 21 deletions(-)

diff --git a/client.ts b/client.ts
index d91df80..39cb24b 100644
--- a/client.ts
+++ b/client.ts
@@ -176,8 +176,7 @@ export class Relay extends NostrNode<ClientToRelayMessage> {
       (resolve, reject) => {
         this.#published.set(event.id, { resolve, reject });
       },
-    ).finally(async () => {
-      await this.#publisher.ready;
+    ).finally(() => {
       this.#published.delete(event.id);
     });
 
diff --git a/deno.json b/deno.json
index 6f3d482..15977d4 100644
--- a/deno.json
+++ b/deno.json
@@ -4,7 +4,7 @@
     "check": "deno check ./**/*.ts",
     "test": "deno test -A --no-check",
     "build": "mkdir -p ./dist && deno run -A ./bin/bundle.ts",
-    "dev": "deno fmt && deno task -q check && deno task -q test"
+    "dev": "deno fmt && deno lint && deno task -q check && deno task -q test"
   },
   "exclude": [
     "dist/",
diff --git a/relay.ts b/relay.ts
index 4722cad..8d51972 100644
--- a/relay.ts
+++ b/relay.ts
@@ -43,33 +43,47 @@ export class Client extends NostrNode<RelayToClientMessage> {
         enqueueRequest = controller.enqueue.bind(controller);
       },
     });
-    this.ws.addEventListener("message", (ev: MessageEvent<string>) => {
+    const writer = this.getWriter();
+    this.ws.addEventListener("message", async (ev: MessageEvent<string>) => {
       // TODO: Validate the type of the message.
       const msg = JSON.parse(ev.data) as ClientToRelayMessage;
+
       // TODO: Apply backpressure when a queue is full.
+
       const kind = msg[0];
       if (kind === "EVENT") {
-        return enqueueEvent(msg[1]);
+        const event = msg[1];
+
+        // TODO: Validate the event and send OkMessage<false> if necessary.
+
+        await writer.ready;
+        writer.write(["OK", event.id, true, ""]);
+        return enqueueEvent(event);
       }
-      const id = msg[1];
+      const sid = msg[1];
       if (kind === "CLOSE") {
-        const sub = this.subscriptions.get(id);
+        const sub = this.subscriptions.get(sid);
         if (!sub) {
+          this.config.logger?.warn?.("Unknown subscription:", sid);
           return;
         }
-        this.subscriptions.delete(id);
+        this.subscriptions.delete(sid);
         return sub.close();
       }
-      // kind === "REQ"
-      const filter = msg[2];
-      const writer = this.getWriter();
-      const writable = new WritableStream<NostrEvent>({
-        write: (event) => {
-          return writer.write(["EVENT", id, event]);
-        },
-      });
-      this.subscriptions.set(id, writable);
-      return enqueueRequest([id, filter]);
+      if (kind === "REQ") {
+        const filter = msg[2];
+        this.subscriptions.set(
+          sid,
+          new WritableStream<NostrEvent>({
+            write: async (event) => {
+              await writer.ready;
+              return writer.write(["EVENT", sid, event]);
+            },
+          }),
+        );
+        return enqueueRequest([sid, filter]);
+      }
+      this.config.logger?.warn?.("Unknown message kind:", kind);
     });
   }
 
diff --git a/tests/relay_test.ts b/tests/relay_test.ts
index 2aec24a..6a50b8c 100644
--- a/tests/relay_test.ts
+++ b/tests/relay_test.ts
@@ -1,4 +1,9 @@
-import { EventMessage, NostrEvent, SubscriptionId } from "../core/nips/01.ts";
+import {
+  EventMessage,
+  NostrEvent,
+  OkMessage,
+  SubscriptionId,
+} from "../core/nips/01.ts";
 import { Client } from "../relay.ts";
 import { afterAll, beforeAll, describe, it } from "../lib/std/testing.ts";
 import { assert, assertEquals } from "../lib/std/assert.ts";
@@ -27,8 +32,13 @@ describe("Client", () => {
     it("should return a ReadableStream of events", () => {
       assert(client.events instanceof ReadableStream);
     });
-    it("should receive events", async () => {
-      const ev = { kind: 0 };
+    it("should receive an event and send a OK message", async () => {
+      const ev = { id: "test-ok", kind: 0 };
+      const received = new Promise<OkMessage>((resolve) => {
+        ws.remote.addEventListener("message", (ev: MessageEvent<string>) => {
+          resolve(JSON.parse(ev.data));
+        });
+      });
       ws.dispatchEvent(
         new MessageEvent("message", {
           data: JSON.stringify(["EVENT", ev]),
@@ -37,6 +47,7 @@ describe("Client", () => {
       const reader = client.events.getReader();
       const { value } = await reader.read();
       assertEquals(value, ev);
+      assertEquals(await received, ["OK", "test-ok", true, ""]);
     });
   });