respect-user-color-scheme enables checking of prefers-color-scheme media query

[gordonwoodhull]

Fixes #1470

When respect-user-color-scheme is enabled (default false), user preference for color scheme will be read from the prefers-color-scheme media query.

This mean that the author preference (via order of light and dark theme or brand in YAML) is unused, as long as JS is enabled. NoJS still uses stylesheet ordering based on author preference. ¹

If the UI dark mode toggle is used, it gets saved to local storage and that take precedence. Currently the user can delete their local storage for the site to go back to their OS default, but in the future we might consider e.g. deleting the local storage setting if it matches the OS setting.

This doesn't do dynamic changes if the OS setting changes, so people who use Auto will have to refresh the page for now.

This tests correctly manually across browsers, but unfortunately it breaks automated tests in unexpected ways, and I haven't figured out how to fix those yet.

In particular, I have tried Changing Color Scheme in Playwright Test to no avail.

Footnotes

1. We might consider a grand refactor using proper media queries, but I am just finding my way around the code and haven't considered that yet. ↩

[gordonwoodhull]

🗝️  When we test prefers-color-schema, we need to set it globally for those tests with test.use().

We don't have dynamic switching in Quarto (yet), so

await page.emulateMedia({ colorScheme: "dark" });

within a test won't work.

[gordonwoodhull]

Seems to be dependency failure

    ! package or namespace load failed for 'flextable':
     package 'openssl' does not have a namespace
    Backtrace:
      1. global .main()
      2. execute(...)
      3. rmarkdown::render(...)
      4. knitr::knit(knit_input, knit_output, envir = envir, quiet = quiet)
      5. knitr:::process_file(text, output)
         ...
           at evaluate/R/evaluate.R:141:5
     17. base (local) withRestartList(expr, restarts)
     18. base (local) withOneRestart(withRestartList(expr, restarts[-nr]), restarts[[nr]])
     19. base (local) docall(restart$handler, restartArgs)
     21. evaluate (local) fun(base::quote(`<smplErrr>`))

[cderv]

Yes possibly a conflict between package that would require update. I'll look at it.

[gordonwoodhull]

Still seeing those flextable / openssl errors. I'm going to merge - pretty sure my tests are not on any of those buckets.

Curious that it only affects this branch and we haven't seen this elsewhere.