fix: disallow publishing pubsub messages to zero peers (#4286)

Use the default gossipsub behaviour of not allowing publishing message
to zero peers.

If a user publishes a message they may be surprised to find it's not
been recieved by anyone, so instead an error should be thrown when there
are no peers that will receive a message.

packages/interface-ipfs-core/src/name-pubsub/pubsub.js

@@ -88,6 +88,14 @@ export function testPubsub (factory, options) {
       const topic = `${namespace}${uint8ArrayToString(routingKey, 'base64url')}`
 
       await nodeB.pubsub.subscribe(topic, () => {})
+
+      // wait for nodeA to see nodeB's subscription
+      await waitFor(async () => {
+        const peers = await nodeA.pubsub.peers(topic)
+
+        return peers.map(p => p.toString()).includes(idB.id.toString())
+      })
+
       await nodeA.name.publish(ipfsRef, { resolve: false })
       await delay(1000) // guarantee record is written
 
@@ -149,6 +157,14 @@ export function testPubsub (factory, options) {
       const topic = `${namespace}${uint8ArrayToString(routingKey, 'base64url')}`
 
       await nodeB.pubsub.subscribe(topic, checkMessage)
+
+      // wait for nodeA to see nodeB's subscription
+      await waitFor(async () => {
+        const peers = await nodeA.pubsub.peers(topic)
+
+        return peers.map(p => p.toString()).includes(idB.id.toString())
+      })
+
       await nodeA.name.publish(ipfsRef, { resolve: false, key: testAccountName })
       await waitFor(alreadySubscribed)
 

packages/interface-ipfs-core/src/pubsub/publish.js

@@ -5,11 +5,30 @@ import { nanoid } from 'nanoid'
 import { getTopic } from './utils.js'
 import { expect } from 'aegir/chai'
 import { getDescribe, getIt } from '../utils/mocha.js'
+import pWaitFor from 'p-wait-for'
 
 /**
  * @typedef {import('ipfsd-ctl').Factory} Factory
+ * @typedef {import('ipfs-core-types').IPFS} IPFS
  */
 
+/**
+ * @param {string} topic
+ * @param {IPFS} ipfs
+ * @param {IPFS} remote
+ */
+async function waitForRemoteToBeSubscribed (topic, ipfs, remote) {
+  await remote.pubsub.subscribe(topic, () => {})
+  const remoteId = await remote.id()
+
+  // wait for remote to be subscribed to topic
+  await pWaitFor(async () => {
+    const peers = await ipfs.pubsub.peers(topic)
+
+    return peers.map(p => p.toString()).includes(remoteId.id.toString())
+  })
+}
+
 /**
  * @param {Factory} factory
  * @param {object} options
@@ -21,30 +40,46 @@ export function testPublish (factory, options) {
   describe('.pubsub.publish', function () {
     this.timeout(80 * 1000)
 
-    /** @type {import('ipfs-core-types').IPFS} */
+    /** @type {IPFS} */
     let ipfs
 
+    /** @type {IPFS} */
+    let remote
+
     before(async () => {
       ipfs = (await factory.spawn()).api
+      remote = (await factory.spawn()).api
+
+      // ensure we have peers to allow publishing
+      const remoteId = await remote.id()
+      await ipfs.swarm.connect(remoteId.addresses[0])
     })
 
     after(() => factory.clean())
 
     it('should fail with undefined msg', async () => {
       const topic = getTopic()
+
+      await waitForRemoteToBeSubscribed(topic, ipfs, remote)
+
       // @ts-expect-error invalid parameter
       await expect(ipfs.pubsub.publish(topic)).to.eventually.be.rejected()
     })
 
-    it('should publish message from buffer', () => {
+    it('should publish message from buffer', async () => {
       const topic = getTopic()
+
+      await waitForRemoteToBeSubscribed(topic, ipfs, remote)
+
       return ipfs.pubsub.publish(topic, uint8ArrayFromString(nanoid()))
     })
 
     it('should publish 10 times within time limit', async () => {
       const count = 10
       const topic = getTopic()
 
+      await waitForRemoteToBeSubscribed(topic, ipfs, remote)
+
       for (let i = 0; i < count; i++) {
         await ipfs.pubsub.publish(topic, uint8ArrayFromString(nanoid()))
       }

packages/ipfs-core-config/src/libp2p-pubsub-routers.browser.js

@@ -5,7 +5,6 @@ import { gossipsub } from '@chainsafe/libp2p-gossipsub'
 /** @type {() => Record<string, (components: any) => PubSub>}>} */
 export const routers = () => ({
   gossipsub: gossipsub({
-    allowPublishToZeroPeers: true,
     fallbackToFloodsub: true,
     emitSelf: true,
     maxInboundStreams: 64,

packages/ipfs-core-config/src/libp2p-pubsub-routers.js

@@ -6,7 +6,6 @@ import { floodsub } from '@libp2p/floodsub'
 /** @type {() => Record<string, (components: any) => PubSub>}>} */
 export const routers = () => ({
   gossipsub: gossipsub({
-    allowPublishToZeroPeers: true,
     fallbackToFloodsub: true,
     emitSelf: true,
     maxInboundStreams: 64,