Unpoly Problem: a[up-accept-location] Attribute Not Working

This repo documents a problem I am having with Unpoly that I am asking for help with.

I cannot replicate the behavior of the "new company" button in the Unpoly demo app on the "all companies" page.

Desired Behavior

1. I navigate to the "companies" page.
2. I click on the "add company" button.
3. The "new company" form pops up in a modal.
4. I submit a valid form.
5. The modal is "accepted" (using the terminology of the Unpoly documentation) and goes away. I am returned to the underlying "companies" page, where the "list of companies" is updated. Only the "list of companies" element (an unordered list with ID #companies-list), should be updated. The random number in the footer should not change.

All of the above steps except #5 work as desired.

Actual Behavior

Instead, this is what happens:

Steps 1 through 4 same as above, then I am redirected to the "example company" page.

Getting Started

Node version: 18

Browser: Chromium 108

Recommended (optional) VSCode extensions for template string syntax highlighting (pick one):

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Endpoints

This is a very simple demo app. These are all of its endpoints:

Method	Path	Purpose
GET	/	Home
GET	/companies	Companies list
POST	/companies	Add company
GET	/companies/new	Form for adding companies
GET	/companies/:id	Individual company (dummy implementation)

Modal Launch

The "add company" button (from views.js):

<a
  href="/companies/new"
  up-layer="new"
  up-accept-location="/companies/$id"
  up-on-accepted="up.reload('#companies-list'); alert('...');"
>
  <button>+ Add company</button>
</a>

The [up-accept-location] attribute doesn't appear to be working.

Successful Form Submission

On successful submission, the "new company" form redirects to /companies/<id>, where the <id> is randomly generated on the fly, and is meant to be a placeholder for demonstration purposes. This can be seen here (from main.js):

// Redirect status code 302
res.redirect(`/companies/${views.randomNumber()}`);

This should cause the modal to close, but it doesn't.

Manually Reload Companies List

On the "companies" page, there is a button to manually reload the #companies-list element. It works. You will notice that the companies list changes while the random number in the footer remains the same. This button's [onclick] attribute is the same as the "new company" button's [up-on-accepted] attribute.

Form Validation

Form validation via Unpoly works flawlessly. This is not an issue. From views.js:

<form method="post" action="/companies" up-validate>...</form>