rollup-timing.ts

function reportRollupTiming(build) {
  if (!build.getTimings) {
    console.log(
      "Rollup timing information is not available. Make sure `perf: true` config is set."
    );
    return;
  }
  const formatTime = (ms) =>
    ms > 1000 ? `${(ms / 1000).toLocaleString()}s` : `${ms.toLocaleString()}ms`;
  const timings = build.getTimings();
  const timingGroups = [];
  let currentGroup;
  for (const key in timings) {
    const time = timings[key][0];
    const label = key.replace(/^[#-\s]+/, "");
    if (key.startsWith("#")) {
      currentGroup = { label, time, items: [] };
      timingGroups.push(currentGroup);
    } else {
      currentGroup.items.push({ label, time });
    }
  }
  let log = [];
  for (const group of timingGroups) {
    const totalMeasured = group.items.reduce((t, i) => t + i.time, 0);
    if (group.time !== totalMeasured && group.items.length) {
      group.items.push({
        label: "(unknown)",
        time: group.time - totalMeasured,
      });
    }
    group.items.sort((a, b) => b.time - a.time);
    log.push(`\n${group.label} (${formatTime(group.time)})`);
    for (const item of group.items) {
      log.push(`  ${item.label.padEnd(40, " ")} ${formatTime(item.time)}`);
    }
  }
  console.log(`\n${log.join("\n")}\n`);
}