Function generateFontFallbacks

packages/fontless/src/css/render.ts:23–41

(family: string, data: FontFaceData, fallbacks?: Array<{ name: string, font: string }>)

}

export async function generateFontFallbacks(family: string, data: FontFaceData, fallbacks?: Array<{ name: string, font: string }>): Promise<string[]> {
  if (!fallbacks?.length)
    return []

  const fontURL = data.src!.find(s => 'url' in s) as RemoteFontSource | undefined
  const metrics = await getMetricsForFamily(family) || (fontURL && await readMetrics(fontURL.originalURL || fontURL.url))

  if (!metrics)
    return []

  const css: string[] = []
  for (const fallback of fallbacks) {
    css.push(generateFallbackFontFace(metrics, {
      ...fallback,
      metrics: await getMetricsForFamily(fallback.font) || undefined,
    }))
  }
  return css
}

const formatMap: Record<string, string> = {
  woff2: 'woff2',