Function createAltTextForTimelineChart

app/utils/charts.ts:741–792

({
  dataset,
  config,
}: AltCopyArgs<EnrichedTimelineSizeCacheEntry[], TimelineChartConfig>)

// Used for TimelineChart.vue
export function createAltTextForTimelineChart({
  dataset,
  config,
}: AltCopyArgs<EnrichedTimelineSizeCacheEntry[], TimelineChartConfig>) {
  if (!dataset) return ''
  const metric =
    config.metric === 'totalSize'
      ? config.$t('package.stats.install_size')
      : config.$t('compare.dependencies')
  const withEvents = dataset.filter(d => d.events.length)
  const first = dataset[0]
  const last = dataset.at(-1)

  if (!first || !last) return ''

  const firstValue = config.metric === 'totalSize' ? first?.totalSize : first?.dependencyCount
  const lastValue = config.metric === 'totalSize' ? last?.totalSize : last?.dependencyCount
  const baseline = firstValue ?? 0
  const current = lastValue ?? baseline
  const overall_progress_percentage =
    baseline > 0 ? Math.round(((current - baseline) / baseline) * 100) : 0

  const version_events = withEvents
    .map(item =>
      config.$t('package.timeline.chart.copy_alt.version_events', {
        version: item.version,
        // eslint-disable-next-line @intlify/vue-i18n/no-dynamic-keys
        events: item.events.map(e => config.$t(e.text).toLocaleLowerCase()).join(', '),
      }),
    )
    .join('; ')

  const key_changes = !withEvents.length
    ? ''
    : config.$t('package.timeline.chart.copy_alt.key_changes', {
        version_events,
      })

  const altText = config.$t('package.timeline.chart.copy_alt.general_description', {
    metric: metric.toLocaleLowerCase(),
    package: config.packageName,
    first: first?.version ?? '',
    last: last?.version ?? '',
    first_value: config.numberFormatter(firstValue ?? 0),
    last_value: config.numberFormatter(lastValue ?? 0),
    overall_progress_percentage,
    key_changes,
    watermark: config.$t('package.trends.copy_alt.watermark'),
  })

  return altText
}

export async function copyAltTextForTimelineChart({
  dataset,