hexojs/hexo · error · TypeError

name is required

Error message

name is required

What it means

Thrown by Tag.register when the 'name' argument is falsy. Tags are custom template tags (e.g. blockquote, codepen) added to the Nunjucks environment by name; an empty name cannot be registered as a Nunjucks extension.

Source

Thrown at lib/extend/tag.ts:220

/**
 * A tag allows users to quickly and easily insert snippets into their posts.
 */
class Tag {
  public env: Environment;
  public source: string;

  constructor() {
    this.env = new Environment(null, {
      autoescape: false
    });
  }

  register(name: string, fn: TagFunction): void
  register(name: string, fn: TagFunction, ends: boolean): void
  register(name: string, fn: TagFunction, options: RegisterOptions): void
  register(name: string, fn: TagFunction, options?: RegisterOptions | boolean):void {
    if (!name) throw new TypeError('name is required');
    if (typeof fn !== 'function') throw new TypeError('fn must be a function');

    if (options == null || typeof options === 'boolean') {
      options = { ends: options as boolean };
    }

    let tag: NunjucksTag;

    if (options.async) {
      let asyncFn: AsyncTagFunction;
      if (fn.length > 2) {
        asyncFn = Promise.promisify(fn);
      } else {
        asyncFn = Promise.method(fn);
      }

      if (options.ends) {
        tag = new NunjucksAsyncBlock(name, asyncFn);

View on GitHub (pinned to 059cb17494)

Solutions

1. Pass a non-empty tag name string.
2. Validate the name source before registering.
3. Ensure the name is a valid Nunjucks extension identifier.

Example fix

// before
hexo.extend.tag.register(tagName, fn);
// after
if (tagName) hexo.extend.tag.register(tagName, fn);

if (!name) throw new Error('tag name required');
hexo.extend.tag.register(name, fn);

const isValidName = (n: unknown): n is string => typeof n === 'string' && n.length > 0;

When it happens

Trigger: Calling hexo.extend.tag.register('', fn) or register(undefined, fn).

Common situations: A tag plugin reads its name from a config field that is empty, or a loop registers tags from a partial map producing undefined keys.

Related errors

• name is required
• fn must be a function
• name is required
• fn must be a function
• name is required

AI-assisted analysis of hexojs/hexo@059cb17494 (2026-08-12). Data as JSON: /api/errors/c30536cb27821fca. Report an issue: GitHub.