Brand fonts from file not picked up by HTML-based formats

[mcanouil]

Bug description

It seems using fonts from file via brand.yml is not working for HTML-based formats.
It does work as expected for Typst assuming the "family" name is the same as the one encoded on the font file.

Steps to reproduce

https://github.com/mcanouil/quarto-issues-experiments/tree/main/quarto-cli-12501

Actual behavior

No fonts imported.

From Garrick:

I can repro using Mickaël’s test-brand-font example. If I take out embed-resources: true and when using a Google font, the compiled bootstrap css has an @import rule as the first line, but with just the source: file font definition there’s no @import rule.
It does work as expected in a Shiny app, but we have a special code path for local files that uses htmltools::HTMLDependency() for the font files and CSS. Here’s a small example app for reference

library(shiny)
library(bslib)

ui <- page_fixed(
  h2("My Shiny App"),
  lorem::ipsum(2)
)

shinyApp(ui, function(...) {})

Quarto check output

Quarto 99.9.9
[✓] Checking environment information...
      Quarto cache location: /Users/mcanouil/Library/Caches/quarto
[✓] Checking versions of quarto binary dependencies...
      Pandoc version 3.6.3: OK
      Dart Sass version 1.85.1: OK
      Deno version 1.46.3: OK
      Typst version 0.13.0: OK
[✓] Checking versions of quarto dependencies......OK
[✓] Checking Quarto installation......OK
      Version: 99.9.9
      commit: 36e704c159d44ad041b819494e3c59fbdeaa5676
      Path: /Users/mcanouil/Projects/quarto-dev/quarto-cli/package/dist/bin

[✓] Checking tools....................OK
      TinyTeX: v2025.03.10
      Chromium: (not installed)

[✓] Checking LaTeX....................OK
      Using: TinyTex
      Path: /Users/mcanouil/Library/TinyTeX/bin/universal-darwin
      Version: 2025

[✓] Checking Chrome Headless....................OK
      Using: Chrome found on system
      Path: /Applications/Brave Browser.app/Contents/MacOS/Brave Browser
      Source: QUARTO_CHROMIUM

[✓] Checking basic markdown render....OK

[✓] Checking Python 3 installation....OK
      Version: 3.13.2
      Path: /opt/homebrew/opt/python@3.13/bin/python3.13
      Jupyter: (None)

      Jupyter is not available in this Python installation.
      Install with python3 -m pip install jupyter

(-) Checking R installation...........ℹ R version 4.4.3 (2025-02-28)
! Config '~/.Rprofile' was loaded!
[✓] Checking R installation...........OK
      Version: 4.4.3
      Path: /Library/Frameworks/R.framework/Resources
      LibPaths:
        - /Library/Frameworks/R.framework/Versions/4.4-arm64/Resources/library
      knitr: 1.50
      rmarkdown: 2.29

[✓] Checking Knitr engine render......OK

[cscheid]

I'm unsure we want to fix this for 1.7, but we'll talk it over in a few minutes in our weekly.

[cderv]

I was curious to learn more about Brand so I looked a but into this.

My understanding is that support for local file in HTML was not added. AFIU the problem is that we don't create the font import string in the SCSS. So the font is not found.

We have bunny and google support

quarto-cli/src/core/sass/brand.ts

Line 89 in 9b7f5df

const bunnyFontImportString = (description: BrandFontCommon) => {

quarto-cli/src/core/sass/brand.ts

Line 118 in 9b7f5df

const googleFontImportString = (description: BrandFontGoogle) => {

but we don't have one for Local font to cover BrandFontFile

quarto-cli/src/resources/types/schema-types.ts

Lines 1467 to 1475 in 9b7f5df

	export type BrandFontFile = {
	family: string;
	files: ((string | {
	path: string;
	style?: BrandFontStyle;
	weight?: BrandFontWeight;
	}))[] /* The font files to include. These can be local or online. Local file paths should be relative to the `brand.yml` file. Online paths should be complete URLs. */;
	source: "file";
	}; /* A method for providing font files directly, either locally or from an online location. */

It seems we don't resolve font file as this is commented and no resolveFilesFontFamily exists

quarto-cli/src/core/sass/brand.ts

Lines 407 to 410 in 9b7f5df

	result.family = resolveGoogleFontFamily(font) ??
	resolveBunnyFontFamily(font) ??
	// resolveFilesFontFamily(font) ??
	family;

The typography import is created in those resolve function

quarto-cli/src/core/sass/brand.ts

Line 344 in 9b7f5df

typographyImports.add(googleFontImportString(resolvedFont));

quarto-cli/src/core/sass/brand.ts

Line 379 in 9b7f5df

typographyImports.add(bunnyFontImportString(resolvedFont));

and we don't have one for local file

So I think this is just unsupported in 1.7. The question is: do we want to add support ? or document the limitation and push to 1.8 ?