Console exception when reflex updates a page that didn't trigger the update

[rockhymas]

Bug Report

Describe the bug

Reflex updates that are not triggered by the client they are being sent to, show a console error:

stimulus_reflex.js:387 Uncaught TypeError: Cannot read property 'completedOperations' of undefined
    at HTMLDocument.beforeDOMUpdateHandler (stimulus_reflex.js:387)
    at dispatch (cable_ready.js:83)
    at Object.morph (cable_ready.js:168)
    at Object.perform (cable_ready.js:349)
    at Subscription.received (stimulus_reflex.js:87)
    at action_cable.js:536
    at Array.map (<anonymous>)
    at Subscriptions.notify (action_cable.js:535)
    at Connection.message (action_cable.js:369)

Introduced by #299. The promises hash doesn't have an entry for the reflexId passed, but there is not check for null/undefined.

To Reproduce

Use the TodoMVC app in two browser tabs, but with StimulusReflex 3.3.0.
Check off a todo.
Note that it gets checked off in the other tab.
But there is also the console error above.

Expected behavior

No javascript error

Versions

StimulusReflex

• Gem: 3.3.0
• Node package: 3.3.0

External tools

• Ruby: 2.6.6
• Rails: 6.0.3
• Node: 10.19.0

Browser

• Browser Chrome
• Version 80

[Schlipak]

I'm having the same issue, seems related to #335.

[leastbad]

Hi @rockhymas, is this issue fixed by running #335 on your local machine?

It'd be really, really helpful to the project if you were able to help us confirm that our fix for your problem works as intended.

[rockhymas]

I'd love to help out. I'm still fairly new to rails and stimulus reflex. How do I go about using a non-released version of stimulusreflex in my rails app?

[leastbad]

You are in luck! I wrote a new documentation section for you the other day:

https://docs.stimulusreflex.com/setup#running-a-branch-to-test-a-github-pull-request

[rockhymas]

Sweet, that got me unblocked for bit. I now have both the gem and the node package, but the javascript isn't being included in webpack now, so I see this error on page load:

Uncaught Error: Cannot find module 'stimulus_reflex'
    at webpackMissingModule (index.js:1)
    at Module../app/javascript/controllers/index.js (index.js:1)
    at __webpack_require__ (bootstrap:19)
    at Module../app/javascript/packs/application.js (application.js:1)
    at __webpack_require__ (bootstrap:19)
    at bootstrap:83
    at bootstrap:83

Yarn is saying I need to link stimulus_reflex, but when I try to do that it says stimulus_reflex isn't registered. I don't want to turn this issue into my personal tech support, but I'm stumped on this one.

[leastbad]

Can you confirm that you've run yarn install --check-files?

Also, if you're on Discord, this could be easier to solve.

[rockhymas]

Yeah, I've run that, output shows no errors. Will jump on discord.

[leastbad]

Hey @rockhymas, are you sorted on this issue?

[rockhymas]

Yeah, this is great, and I've learned a lot. Thanks again.