node/test/parallel/test-diagnostics-channel-object-channel-pub-sub.js
simon-id d0670e7559 lib: add return value for DC channel.unsubscribe
PR-URL: https://github.com/nodejs/node/pull/40433
Reviewed-By: Vladimir de Turckheim <vlad2t@hotmail.com>
Reviewed-By: Stephen Belanger <admin@stephenbelanger.com>
Reviewed-By: Gerhard Stöbich <deb2001-github@yahoo.de>
Reviewed-By: Michael Dawson <midawson@redhat.com>
Reviewed-By: Bryan English <bryan@bryanenglish.com>
Reviewed-By: Zijian Liu <lxxyxzj@gmail.com>
2021-10-19 14:46:13 +00:00

47 lines
1.2 KiB
JavaScript

'use strict';
const common = require('../common');
const dc = require('diagnostics_channel');
const assert = require('assert');
const { Channel } = dc;
const input = {
foo: 'bar'
};
// Should not have named channel
assert.ok(!dc.hasSubscribers('test'));
// Individual channel objects can be created to avoid future lookups
const channel = dc.channel('test');
assert.ok(channel instanceof Channel);
// No subscribers yet, should not publish
assert.ok(!channel.hasSubscribers);
const subscriber = common.mustCall((message, name) => {
assert.strictEqual(name, channel.name);
assert.deepStrictEqual(message, input);
});
// Now there's a subscriber, should publish
channel.subscribe(subscriber);
assert.ok(channel.hasSubscribers);
// The ActiveChannel prototype swap should not fail instanceof
assert.ok(channel instanceof Channel);
// Should trigger the subscriber once
channel.publish(input);
// Should not publish after subscriber is unsubscribed
assert.ok(channel.unsubscribe(subscriber));
assert.ok(!channel.hasSubscribers);
// unsubscribe() should return false when subscriber is not found
assert.ok(!channel.unsubscribe(subscriber));
assert.throws(() => {
channel.subscribe(null);
}, { code: 'ERR_INVALID_ARG_TYPE' });