Subscribe / Unsubscribe error

Open

#96 opened on Mar 1, 2021 1 comment 0 reactions 0 assignees View on GitHub

Nobody has claimed this yet.

Assessment

Difficulty: 3/5
Estimated time: 1-2 days
Newbie friendliness: 25/100

Issue type: Bug
Clarity: Needs clarification
Activity status: Stale
Tech stack: javascript, node.js
Domain: api, backend

Research direction

Reproduce the subscription flow in the Example directory, then inspect node_modules/metacom/lib/channel.js at line 75 and application/api/example.1/subscribe.js at line 4, where the reported error originates. Trace why the client connection is undefined after refresh; done means subscribe and unsubscribe no longer produce the TypeError.

Written by the indexing model from the issue text.

Description

Node version: 14.15.3
OS: MacOS 11.2.1

In Example directory:

rm -R node_modules
git pull
npm install

Example version: 1.1.2

"devDependencies": {
    "@types/node": "^14.14.31",
    "eslint": "^7.21.0",
    "metatests": "^0.7.2"
  },
  "dependencies": {
    "impress": "^2.0.11",
    "metasql": "^0.3.0-alpha.3",
    "redis": "^3.0.2"
  }

Metacom:

  "name": "metacom",
  "version": "1.5.3",

Write in browser console: await api.example.subscribe()
Refresh page
And in macos console:

23:55:42  W2   error   TypeError: Cannot read property 'connection' of undefined
  Client.emit (/node_modules/metacom/lib/channel.js:75:18)
  Timeout._onTimeout (/application/api/example.1/subscribe.js:4:20)
  listOnTimeout (internal/timers.js:554:17)
  processTimers (internal/timers.js:497:7)

Full console:

00:09:27  W3   info    Listen port 7002 in worker 3
00:09:27  W1   info    Listen port 7000 in worker 1
00:09:27  W2   info    Listen port 7001 in worker 2
00:09:27  W1   debug   Start example plugin
00:09:27  W1   debug   { set: { key: 'keyName', val: 100 } }
00:09:27  W1   debug   { get: 'keyName', return: 100 }
00:09:27  W1   debug   { res: 100, cache: undefined }
00:09:27  W1   debug   Connect to redis
00:09:27  W1   debug   Connect to pg
00:09:27  W1   debug   Connect to metacom
00:09:27  W2   log     127.0.0.1	system/introspect
00:09:27  W3   info    Application started in worker 3
00:09:27  W2   log     127.0.0.1	system/introspect
00:09:27  W2   log     127.0.0.1	system/introspect
00:09:27  W2   log     127.0.0.1	system/introspect
00:09:27  W4   info    Application started in worker 4
00:09:27  W1   info    Application started in worker 1
00:09:27  W2   info    Application started in worker 2
00:09:27  W2   log     127.0.0.1	system/introspect
00:09:27  W5   info    Application started in worker 5
00:09:49  W3   log     127.0.0.1	GET	/
00:09:50  W3   log     127.0.0.1	GET	/console.css
00:09:50  W3   log     127.0.0.1	GET	/console.js
00:09:50  W3   log     127.0.0.1	GET	/metarhia.svg
00:09:50  W3   log     127.0.0.1	GET	/metacom.js
00:09:50  W3   log     127.0.0.1	GET	/events.js
00:09:50  W3   log     127.0.0.1	GET	/manifest.json
00:09:50  W3   log     127.0.0.1	system/introspect
00:09:50  W3   debug   SELECT data FROM "SystemSession" WHERE token = $1	[jaj1rzAZciWBSVX2bWtwslsulwU2IIib4VLaYwTFtxszi5kdBeodayvNK5y516ad]
00:09:50  W3   log     127.0.0.1	GET	/metarhia.png
00:09:50  W3   log     127.0.0.1	auth/restore
00:09:50  W3   log     127.0.0.1	console/content
00:09:52  W3   log     127.0.0.1	GET	/worker.js
00:10:02  W3   log     127.0.0.1	example/subscribe
00:10:07  W3   log     127.0.0.1	GET	/
00:10:07  W3   log     127.0.0.1	GET	/console.css
00:10:07  W3   log     127.0.0.1	GET	/console.js
00:10:07  W3   log     127.0.0.1	GET	/metarhia.svg
00:10:07  W3   log     127.0.0.1	GET	/metacom.js
00:10:07  W3   log     127.0.0.1	GET	/events.js
00:10:07  W3   error   TypeError: Cannot read property 'connection' of undefined
  Client.emit (/node_modules/metacom/lib/channel.js:75:18)
  Timeout._onTimeout (/application/api/example.1/subscribe.js:4:20)
  listOnTimeout (internal/timers.js:554:17)
  processTimers (internal/timers.js:497:7)
00:10:07  W3   log     127.0.0.1	GET	/manifest.json
00:10:07  W3   log     127.0.0.1	GET	/favicon.ico
00:10:07  W3   log     127.0.0.1	system/introspect
00:10:07  W3   debug   SELECT data FROM "SystemSession" WHERE token = $1	[jaj1rzAZciWBSVX2bWtwslsulwU2IIib4VLaYwTFtxszi5kdBeodayvNK5y516ad]
00:10:07  W3   log     127.0.0.1	GET	/metarhia.png
00:10:07  W3   log     127.0.0.1	GET	/favicon.ico
00:10:07  W3   log     127.0.0.1	auth/restore
00:10:07  W3   log     127.0.0.1	console/content
00:10:08  W3   error   TypeError: Cannot read property 'connection' of undefined
  Client.emit (/node_modules/metacom/lib/channel.js:75:18)
  Timeout._onTimeout (/application/api/example.1/subscribe.js:4:20)
  listOnTimeout (internal/timers.js:554:17)
  processTimers (internal/timers.js:497:7)
00:10:09  W3   log     127.0.0.1	GET	/worker.js
00:10:09  W3   error   TypeError: Cannot read property 'connection' of undefined
  Client.emit (/node_modules/metacom/lib/channel.js:75:18)
  Timeout._onTimeout (/application/api/example.1/subscribe.js:4:20)
  listOnTimeout (internal/timers.js:554:17)
  processTimers (internal/timers.js:497:7)
00:10:09  W1   info    Graceful shutdown in worker 1
00:10:09  W2   info    Graceful shutdown in worker 2
00:10:09  W3   info    Graceful shutdown in worker 3
00:10:09  W4   info    Graceful shutdown in worker 4
00:10:09  W5   info    Graceful shutdown in worker 5
00:10:09  W1   debug   Stop example plugin
00:10:09  W2   debug   Stop example plugin
00:10:09  W3   debug   Stop example plugin
00:10:10  W3   error   TypeError: Cannot read property 'connection' of undefined
  Client.emit (/node_modules/metacom/lib/channel.js:75:18)
  Timeout._onTimeout (/application/api/example.1/subscribe.js:4:20)
  listOnTimeout (internal/timers.js:554:17)
  processTimers (internal/timers.js:497:7)
00:10:11  W3   error   TypeError: Cannot read property 'connection' of undefined
  Client.emit (/node_modules/metacom/lib/channel.js:75:18)
  Timeout._onTimeout (/application/api/example.1/subscribe.js:4:20)
  listOnTimeout (internal/timers.js:554:17)
  processTimers (internal/timers.js:497:7)
00:10:12  W3   error   TypeError: Cannot read property 'connection' of undefined
  Client.emit (/node_modules/metacom/lib/channel.js:75:18)
  Timeout._onTimeout (/application/api/example.1/subscribe.js:4:20)
  listOnTimeout (internal/timers.js:554:17)
  processTimers (internal/timers.js:497:7)
00:10:13  W3   error   TypeError: Cannot read property 'connection' of undefined
  Client.emit (/node_modules/metacom/lib/channel.js:75:18)
  Timeout._onTimeout (/application/api/example.1/subscribe.js:4:20)
  listOnTimeout (internal/timers.js:554:17)
  processTimers (internal/timers.js:497:7)
00:10:14  W3   error   TypeError: Cannot read property 'connection' of undefined
  Client.emit (/node_modules/metacom/lib/channel.js:75:18)
  Timeout._onTimeout (/application/api/example.1/subscribe.js:4:20)
  listOnTimeout (internal/timers.js:554:17)
  processTimers (internal/timers.js:497:7)

Dominant language: JavaScript
Stars: 211
Forks: 82
PR merge metrics: No merged PRs in 30d

Contributor guide

No contributing guide indexed for this repository

First steps

Read the whole issue, then the project's contributing guide.
Comment on the issue to say you are picking it up — it saves two people doing the same work.
Fork the repository and make your change on a branch.
Open a pull request that references the issue number.

Similar issues

custom-resources teaches static verbs without the authorization obligation Open

Difficulty 2/5 1-3 hours Newbie friendliness 88/100

HarperFast/skills#96 · Opened Sep 22, 2026
Latest Posts: text decoration "None" has no effect on post title links Open

[Block] Latest Posts [Type] Bug

Difficulty 2/5 1-3 hours Newbie friendliness 76/100

WordPress/gutenberg#83300 · Opened Sep 21, 2026
Daemon passes --experimental-wasm-jspi unconditionally on Node >= 24; Node 26 rejects the flag Open

Difficulty 2/5 1-3 hours Newbie friendliness 78/100

Automattic/studio#4908 · Opened Sep 21, 2026
Failed link preload leaves an unhandled rejection in production builds (3.0.0-next.27) Open

Difficulty 2/5 1-3 hours Newbie friendliness 74/100

sveltejs/kit#17178 · Opened Sep 21, 2026
[Bug] Filter on a basic oscillator throws in _performNotes and silences the note Open

Difficulty 2/5 1-3 hours Newbie friendliness 86/100

sugarlabs/musicblocks#8847 · Opened Sep 21, 2026

More JavaScript issues