fix: fix IPv6 related multicast problem

lib/server.ts

@@ -259,7 +259,7 @@ class CoAPServer extends EventEmitter {
                             multicastAddress,
                             this._multicastInterface
                         )
-                    } else {
+                    } else if (this._options.type === 'udp4') {
                         allAddresses(this._options.type).forEach((
                             _interface
                         ) => {
@@ -268,6 +268,10 @@ class CoAPServer extends EventEmitter {
                                 _interface
                             )
                         })
+                    } else {
+                        // FIXME: Iterating over all network interfaces does not
+                        //        work for IPv6 at the moment
+                        sock.addMembership(multicastAddress)
                     }
                 }
             } catch (err) {

package.json

@@ -1,6 +1,6 @@
 {
   "name": "coap",
-  "version": "1.0.6",
+  "version": "1.0.7",
   "description": "A CoAP library for node modelled after 'http'",
   "main": "dist/index.js",
   "types": "dist/index.d.ts",

test/server.ts

@@ -9,7 +9,7 @@
 import { parse, generate } from 'coap-packet'
 import { nextPort } from './common'
 import { expect } from 'chai'
-import { CoapPacket, Option } from '../models/models'
+import { CoapPacket, CoapServerOptions, Option } from '../models/models'
 import { request, createServer } from '../index'
 import { createSocket } from 'dgram'
 import BufferListStream = require('bl')
@@ -1000,22 +1000,43 @@ describe('server', function () {
     describe('multicast', function () {
         const port = nextPort()
 
-        it('receive CoAP message', function (done) {
-            const server = createServer({
-                multicastAddress: '224.0.1.2'
-            })
+        const testVector: Array<CoapServerOptions & {addressType: string}> = [
+            {
+                addressType: 'IPv4',
+                multicastAddress: '224.0.1.2',
+                type: 'udp4'
+            },
+            {
+                addressType: 'IPv6',
+                multicastAddress: 'ff02::fd',
+                type: 'udp6'
+            }]
 
-            server.listen(port)
+        testVector.forEach(({ addressType, multicastAddress, type }) => {
+            it(`receive ${addressType} CoAP message`, function (done) {
+                if (addressType === 'IPv6' && process.platform === 'darwin') {
+                    // FIXME: IPv6 multicast seems to have problems on macos
+                    //        at the moment
+                    this.skip()
+                }
 
-            server.once('request', (req, res) => {
-                done()
-            })
+                const server = createServer({
+                    multicastAddress,
+                    type
+                })
 
-            request({
-                host: '224.0.1.2',
-                port: port,
-                multicast: true
-            }).end()
+                server.listen(port)
+
+                server.once('request', (req, res) => {
+                    done()
+                })
+
+                request({
+                    host: multicastAddress,
+                    port: port,
+                    multicast: true
+                }).end()
+            })
         })
     })
 })