vercel__eve/scripts/nitro-bundle-report-budget.mjs

import { readFile } from "node:fs/promises";
import { resolve } from "node:path";
import { fileURLToPath } from "node:url";

function formatBytes(bytes) {
  if (bytes < 1_000) {
    return `${bytes} B`;
  }

  if (bytes < 1_000_000) {
    return `${(bytes / 1_000).toFixed(1)} kB`;
  }

  return `${(bytes / 1_000_000).toFixed(2)} MB`;
}

function formatRatioPercent(ratio) {
  if (!Number.isFinite(ratio)) {
    return "new";
  }

  return `${(ratio * 100).toFixed(1)}%`;
}

function formatFailure(check) {
  if (check.kind === "runtime-dependency") {
    return `New runtime dependency ${check.dependency} was added. Runtime dependencies increase the install footprint; prefer a vendored devDependency when possible`;
  }

  return `${check.metric} grew ${formatRatioPercent(check.increaseRatio)} (${formatBytes(check.baseline)} -> ${formatBytes(check.current)}), above the ${formatRatioPercent(check.thresholdRatio)} limit`;
}

function printUsage() {
  process.stdout.write(
    [
      "Usage: node ./scripts/nitro-bundle-report-budget.mjs --report-json <path> [options]",
      "",
      "Options:",
      "  --report-json <path>  Bundle report JSON generated by nitro-bundle-report.mjs",
      "  --acknowledged        Allow budget failures to pass",
      "  --help                Show this help text",
      "",
    ].join("\n"),
  );
}

function parseArguments(argv) {
  const parsedArguments = {
    acknowledged: false,
    reportJsonPath: null,
  };

  for (let index = 0; index < argv.length; index += 1) {
    const argument = argv[index];

    if (argument === "--help") {
      printUsage();
      process.exit(0);
    }

    if (argument === "--acknowledged") {
      parsedArguments.acknowledged = true;
      continue;
    }

    const value = argv[index + 1];

    if (value === undefined) {
      throw new Error(`Missing value for "${argument}".`);
    }

    if (argument === "--report-json") {
      parsedArguments.reportJsonPath = value;
      index += 1;
      continue;
    }

    throw new Error(`Unknown argument "${argument}".`);
  }

  if (parsedArguments.reportJsonPath === null) {
    throw new Error('The "--report-json" option is required.');
  }

  return parsedArguments;
}

async function main() {
  const args = parseArguments(process.argv.slice(2));
  const report = JSON.parse(await readFile(resolve(args.reportJsonPath), "utf8"));
  const sizeBudget = report.comparison?.sizeBudget;

  if (!sizeBudget) {
    process.stdout.write("No baseline comparison is available; skipping bundle warning policy.\n");
    return;
  }

  const failures = sizeBudget.checks.filter((check) => check.failed);

  if (failures.length === 0) {
    process.stdout.write("Bundle warning policy passed.\n");
    return;
  }

  const messageLines = [
    "Bundle warning policy exceeded:",
    ...failures.map((failure) => `- ${formatFailure(failure)}`),
    "",
    "The pull request comment contains the same failure details.",
  ];

  if (args.acknowledged) {
    process.stdout.write(
      `${messageLines.join("\n")}\nThe acknowledge-bundle-warning label is present, so this check is passing.\n`,
    );
    return;
  }

  process.stderr.write(
    `${messageLines.join("\n")}\nAdd the acknowledge-bundle-warning label to acknowledge the regression and pass without regenerating the report.\n`,
  );
  process.exitCode = 1;
}

const executedScriptPath = process.argv[1] ? resolve(process.argv[1]) : null;
const moduleScriptPath = resolve(fileURLToPath(import.meta.url));

if (
  executedScriptPath !== null &&
  moduleScriptPath !== null &&
  executedScriptPath === moduleScriptPath
) {
  await main();
}