WIP: add diagnostic channel for server creation

lib/channels.js

@@ -0,0 +1,15 @@
+'use strict';
+
+exports = module.exports = {};
+
+try {
+    const DiagnosticsChannel = require('diagnostics_channel');
+
+    exports = module.exports = {
+        serverChannel: DiagnosticsChannel.channel('hapi:server')
+    };
+}
+catch {
+    // diagnostics_channel is not supported (e.g. node 12)
+}
+

lib/server.js

@@ -5,6 +5,7 @@ const Shot = require('@hapi/shot');
 const Somever = require('@hapi/somever');
 const Teamwork = require('@hapi/teamwork');
 
+const Channels = require('./channels');
 const Config = require('./config');
 const Core = require('./core');
 const Cors = require('./cors');
@@ -85,6 +86,10 @@ internals.Server = class {
         }
 
         core.registerServer(this);
+
+        if (Channels.serverChannel && Channels.serverChannel.hasSubscribers) {
+            Channels.serverChannel.publish(this);
+        }
     }
 
     _clone(name) {

test/server.js

@@ -2941,6 +2941,34 @@ describe('Server', () => {
             expect(res3.result).to.equal('<h1>grabbed</h1>');
         });
     });
+
+    describe('Diagnostics channel', () => {
+
+        it('Fires server event on server creation', async () => {
+
+            // If diagnostics_channel is not supported (node 12), skip test
+            try {
+                require('diagnostics_channel');
+            }
+            catch {
+                return Promise.resolve();
+            }
+
+            const DiagnosticsChannel = require('diagnostics_channel');
+
+            const serverChannel = DiagnosticsChannel.channel('hapi:server');
+            return await new Promise((resolve) => {
+
+                serverChannel.subscribe((server) => {
+
+                    expect(server).to.exist();
+                    resolve();
+                });
+
+                new Hapi.Server();
+            });
+        });
+    });
 });