'use strict'; const common = require('../common'); const dc = require('node:diagnostics_channel'); const channel_name = 'test:channel'; const published_data = 'some message'; const onMessageHandler = common.mustCall(() => dc.unsubscribe(channel_name, onMessageHandler)); dc.subscribe(channel_name, onMessageHandler); dc.subscribe(channel_name, common.mustCall()); // This must not throw. dc.channel(channel_name).publish(published_data);