message: [now-build-utils] Add `bypassToken` to `Prerender` for iSSG
  This pull request adds a new `bypassToken` field to the `Prerender` output.
  The field is required to be at least 128 bits for security reasons!
diff: @@ -8,6 +8,7 @@ interface PrerenderOptions {
  lambda: Lambda;
  fallback: FileBlob | FileFsRef | FileRef | null;
  group?: number;
  + bypassToken?: string | null /* optional to be non-breaking change */;
  }
  export class Prerender {
  @@ -16,8 +17,15 @@ export class Prerender {
  public lambda: Lambda;
  public fallback: FileBlob | FileFsRef | FileRef | null;
  public group?: number;
  + public bypassToken: string | null;
  - constructor({ expiration, lambda, fallback, group }: PrerenderOptions) {
  + constructor({
  + expiration,
  + lambda,
  + fallback,
  + group,
  + bypassToken,
  + }: PrerenderOptions) {
  this.type = 'Prerender';
  this.expiration = expiration;
  this.lambda = lambda;
  @@ -32,6 +40,22 @@ export class Prerender {
  }
  this.group = group;
  + if (bypassToken == null) {
  + this.bypassToken = null;
  + } else if (typeof bypassToken === 'string') {
  + if (bypassToken.length < 32) {
  + // Enforce 128 bits of entropy for safety reasons (UUIDv4 size)
  + throw new Error(
  + 'The `bypassToken` argument for `Prerender` must be 32 characters or more.'
  + );
  + }
  + this.bypassToken = bypassToken;
  + } else {
  + throw new Error(
  + 'The `bypassToken` argument for `Prerender` must be a `string`.'
  + );
  + }
  +
  if (typeof fallback === 'undefined') {
  throw new Error(
  'The `fallback` argument for `Prerender` needs to be a `FileBlob`, `FileFsRef`, `FileRef`, or null.'
  