🪲 UniqueStaticBlockId false positive on official Horizon theme — duplicate id is intentional (variant parameter)

[michellepace]

Describe the bug

Running shopify theme check on the official Horizon theme collection (unmodified) was expected to pass with no errors. Instead, 2 errors and 23 warnings were found.

The 2 errors appear to be a false positive in the UniqueStaticBlockId check because the duplicate id is intentional (I think) — the same static block is rendered with different variant parameters to produce desktop, mobile drawer, and navigation bar versions of the header menu from a single set of merchant-configurable settings.

Reproduced on:

• https://themes.shopify.com/themes/dwell/presets/dwell
• https://github.com/Shopify/horizon

Source

{% capture menu %}
  {% content_for 'block', type: '_header-menu', id: 'header-menu' %}
{% endcapture %}

{% capture drawer_menu %}
  {% content_for 'block', type: '_header-menu', id: 'header-menu', variant: 'mobile' %}
{% endcapture %}

{% capture navigation_bar %}
  {% content_for 'block', type: '_header-menu', id: 'header-menu', variant: 'navigation_bar', transparent: transparent %}
{% endcapture %}

Expected behaviour

Running shopify theme check on unmodified official Horizon themes should pass with 0 errors. The UniqueStaticBlockId check should not flag duplicate static block ids when the calls are differentiated by the variant parameter, as the shared id is deliberate — it ensures the Theme Editor shows a single configurable block whose settings apply to all renderings.

Actual behaviour

Two errors are reported:

sections/header.liquid:55 - [error] UniqueStaticBlockId - The id 'header-menu' is already being used by another static block
sections/header.liquid:59 - [error] UniqueStaticBlockId - The id 'header-menu' is already being used by another static block

The theme functions correctly at runtime — the Liquid engine renders all three variants, and merchants see a single block in the Theme Editor as intended. The error is purely a linting false positive.

Debugging information

• OS: Linux (WSL2)
• OS Version: 6.6.87.2-microsoft-standard-WSL2
• Shopify CLI: 3.91.0
• Theme: Horizon collection — Dwell v3.4.0

Additional context

• The identical code and identical errors are present in the official Shopify/horizon repository.
• The variant parameter is a documented feature of content_for 'block' that allows a single block definition to render different markup based on context.
• Giving each call a unique id (e.g. header-menu-desktop, header-menu-mobile, header-menu-navbar) would "fix" the lint error but break the intended UX — merchants would see three separate blocks in the editor and have to configure menu settings three times.
• The check's own documentation states "Disabling this check isn't recommended", which makes the false positive particularly confusing for theme developers encountering it in Shopify's own themes.