Fluid font size application is dependent on the global state

[costasovo]

Description

I'm working with WP_Theme_JSON class. I feed it with a decode theme.json and use to generate styles I want to use in a custom editor.
The issue is that even though I specify set settings.typography.fluid to false and provide values in pixels the styles generated by WP_Theme_JSON::get_stylesheet still contain the values converted to clamp function.

This seems to happen because wp_get_typography_font_size_value checks the global settings to see if the fluid font size is enabled. So if the site is configured to use the fluid font size it is always applied no matter what value I configure in data I pass to WP_Theme_JSON.

To add more context, my use case is a custom Gutenberg email editor, and I want to disable the fluid font size because clamp is not supported in many email clients.

Step-by-step reproduction instructions

1. I have a WP site running on v 6.4, and I use The Twenty-Three theme.
2. I use the following code snippet

$themeJsonData = '{
      "version": 2,
      "settings": {
        "typography": {
          "fluid": false
        }
      },
      "styles": {
        "elements": {
          "h1": {
            "typography": {
              "fontSize": "48px",
              "fluid": false
            }
          }
        }
      }
    }';
    $themeJson = new \WP_Theme_JSON(json_decode($themeJsonData, true), 'default');
    $css = $themeJson->get_stylesheet();

3. The generated CSS containsh1{font-size: clamp(27.894px, 1.743rem + ((1vw - 3.2px) * 2.285), 48px);}
   but I would expect h1{font-size: 48px;}

Screenshots, screen recording, code snippet

No response

Environment info

• WordPress 6.4
• I use the Gutenberg version distributed in the WordPress
• Twenty Twenty-Three theme

Please confirm that you have searched existing issues in the repo.

Yes

Please confirm that you have tested with all plugins deactivated except Gutenberg.

Yes

[ramonjd]

Thanks for reporting!

[ramonjd]

I have a WIP idea going on over at:

• Fluid typography: pass theme.json settings to override merged theme data #58362