Function readMetrics

packages/fontaine/src/metrics.ts:68–97

(_source: URL | string)

 * @async
 */
export async function readMetrics(_source: URL | string): Promise<FontFaceMetrics | null> {
  const source = typeof _source !== 'string' && 'href' in _source ? _source.href : _source

  if (source in metricCache)
    return metricCache[source] ?? null

  const { protocol } = parseURL(source)
  if (!protocol)
    return null

  let metrics: Font
  if (protocol === 'file:') {
    metrics = await fromFile(fileURLToPath(source))
  }
  else {
    if (urlRequestCache.has(source)) {
      metrics = await urlRequestCache.get(source)!
    }
    else {
      const requestPromise = fromUrl(source)
      urlRequestCache.set(source, requestPromise)

      metrics = await requestPromise
    }
  }

  const filteredMetrics = filterRequiredMetrics(metrics)
  metricCache[source] = filteredMetrics
  return filteredMetrics
}

// inline `@capsizecss/metrics`
// https://github.com/seek-oss/capsize/blob/66344699ff7759a661a78d0629375714c6f308b0/packages/metrics/src/index.ts