nodejs
diff --git a/‎lib/diagnostics_channel.js‎
Lines changed: 1 addition & 0 deletions b/‎lib/diagnostics_channel.js‎
Lines changed: 1 addition & 0 deletions
diff --git a/‎test/parallel/test-diagnostics-channel-object-channel-pub-sub.js‎
Lines changed: 2 additions & 0 deletions b/‎test/parallel/test-diagnostics-channel-object-channel-pub-sub.js‎
Lines changed: 2 additions & 0 deletions
diff --git a/‎test/parallel/test-diagnostics-channel-pub-sub.js‎
Lines changed: 2 additions & 0 deletions b/‎test/parallel/test-diagnostics-channel-pub-sub.js‎
Lines changed: 2 additions & 0 deletions
@@ -229,6 +229,7 @@ class Channel {
   }
 
   subscribe(subscription) {
+    validateFunction(subscription, 'subscription');
     markActive(this);
     this.subscribe(subscription);
   }
 
@@ -44,3 +44,5 @@ assert.ok(!channel.unsubscribe(subscriber));
 assert.throws(() => {
   channel.subscribe(null);
 }, { code: 'ERR_INVALID_ARG_TYPE' });
+assert.ok(!channel.hasSubscribers);
+assert.ok(!dc.hasSubscribers('test'));
@@ -42,6 +42,8 @@ assert.ok(!dc.unsubscribe(name, subscriber));
 assert.throws(() => {
   dc.subscribe(name, null);
 }, { code: 'ERR_INVALID_ARG_TYPE' });
+assert.ok(!channel.hasSubscribers);
+assert.ok(!dc.hasSubscribers(name));
 
 // Reaching zero subscribers should not delete from the channels map as there
 // will be no more weakref to incRef if another subscribe happens while the
Original file line number	Diff line number	Diff line change
`@@ -229,6 +229,7 @@ class Channel {`
`229`	`229`	`}`
`230`	`230`
`231`	`231`	`subscribe(subscription) {`
	`232`	`+ validateFunction(subscription, 'subscription');`
`232`	`233`	`markActive(this);`
`233`	`234`	`this.subscribe(subscription);`
`234`	`235`	`}`