Function readLocalVercelPackageJson

packages/cli-exec/src/lookup.ts:682–719

* Reads and validates the local `vercel` package metadata file.

(
  realPackageDirectory: string
)

 * Reads and validates the local `vercel` package metadata file.
 */
async function readLocalVercelPackageJson(
  realPackageDirectory: string
): Promise<
  { packageJson: { name?: unknown; bin?: unknown } } | { reason: string }
> {
  const packageJsonPath = path.join(realPackageDirectory, 'package.json');
  const realPackageJsonPath = await realpath(packageJsonPath);

  if (!isSubpath(realPackageDirectory, realPackageJsonPath)) {
    return { reason: 'local vercel package.json resolves outside package' };
  }

  const unsafePackageJsonReason = await getUnsafePackageFileReason(
    realPackageDirectory,
    realPackageJsonPath
  );

  if (unsafePackageJsonReason) {
    return {
      reason: `local vercel package.json is unsafe: ${unsafePackageJsonReason}`,
    };
  }

  const packageJson = JSON.parse(
    await readFile(realPackageJsonPath, 'utf8')
  ) as {
    name?: unknown;
    bin?: unknown;
  };

  if (packageJson.name !== 'vercel') {
    return {
      reason: 'local vercel package.json does not have name "vercel"',
    };
  }

  return { packageJson };
}

/**
 * Resolves and validates the bin declared by the local `vercel` package.