Percent of pages that include link[rel=alternate] for stylesheets

http_archive_css_alternate.sql

#standardSQL
# Percent of pages that include link[rel=alternate] for stylesheets
# Warning this uses 500GB of BigQuery usage so can be expensive to run multiple times!
CREATE TEMP FUNCTION hasAlternateCSS(payload STRING)
RETURNS BOOLEAN LANGUAGE js AS '''
  try {
    var $ = JSON.parse(payload);
    var almanac = JSON.parse($._almanac);
    return !!almanac['link-nodes'].find(
      e => e.rel.toLowerCase().includes('alternate')
      &&
      (
        e.as.toLowerCase() == 'style' || e.href.toLowerCase().includes('.css') || e.type.toLowerCase() == 'text/css'
      )
     );
  } catch (e) {
    return false;
  }
''';

SELECT
  _TABLE_SUFFIX AS client,
  COUNTIF(hasAlternateCSS(payload)) AS num_pages,
  COUNT(0) AS total,
  ROUND(COUNTIF(hasAlternateCSS(payload)) * 100 / COUNT(0), 2) AS pct_alternate_css
FROM
  `httparchive.pages.2020_05_01_*`
GROUP BY
  client

Results as of 1st May 2020:

Row	client	num_pages	total	pct_alternate_css
1	mobile	3	5349874	0.0
2	desktop	2	4507943	0.0