Place code in files that match its functionality. When functionality applies to multiple components, use a general-purpose file rather than component-specific ones. This improves maintainability and makes the codebase easier to navigate.

For example, instead of:

// In inlines.js
$('.js-inline-admin-formset fieldset.module.collapse:not(.open) details[open]').each(function() {
    this.removeAttribute('open');
});

Prefer:

// In a more general file like change_form.js
document.querySelectorAll('fieldset.module.collapse:not(.open) details[open]').forEach(details => {
    details.removeAttribute('open');
});

Additionally, use modern JavaScript patterns where appropriate to improve code consistency and readability.