facebook/docusaurus · error · Error

A Docusaurus plugin is missing a 'name' property.\nNote that

Error message

A Docusaurus plugin is missing a 'name' property.\nNote that even inline/anonymous plugin functions require a 'name' property.

What it means

Thrown during plugin initialization when the plugin returns a non-null object that lacks a `name` property. Docusaurus relies on `name` to namespace plugin content, options, and IDs; anonymous plugins break that contract. Even inline plugin functions must declare a `name`. The check is at plugins/init.ts:158-163.

Source

Thrown at packages/docusaurus/src/server/plugins/init.ts:160

      pluginOptions,
    );

    // Returning null has been explicitly allowed
    // It's a way for plugins to self-disable depending on context
    // See https://github.com/facebook/docusaurus/pull/10286
    if (pluginInstance === null) {
      return {config: normalizedPluginConfig, plugin: null};
    }
    if (pluginInstance === undefined) {
      throw new Error(
        `A Docusaurus plugin returned 'undefined', which is forbidden.
A plugin is expected to return an object having at least a 'name' property.
If you want a plugin to self-disable depending on context/options, you can explicitly return 'null' instead of 'undefined'`,
      );
    }

    if (!pluginInstance?.name) {
      throw new Error(
        `A Docusaurus plugin is missing a 'name' property.
Note that even inline/anonymous plugin functions require a 'name' property.`,
      );
    }

    const plugin: InitializedPlugin = {
      ...pluginInstance,
      options: pluginOptions,
      version: pluginVersion,
      path: path.dirname(normalizedPluginConfig.entryPath),
    };

    return {
      config: normalizedPluginConfig,
      plugin,
    };
  }

View on GitHub (pinned to 3f483e80e3)

Solutions

Add a stable `name` string to the returned plugin object (e.g. `'my-plugin'`).
For function plugins, give the function itself a `name` (function declaration) — but explicit `name` in the returned object is safest.
Use the `Plugin` type from `@docusaurus/types` to make missing `name` a compile error.

Example fix

// before
plugins: [() => ({ loadContent: () => null })],
// after
plugins: [() => ({ name: 'my-plugin', loadContent: () => null })],

Defensive patterns

Strategy: type-guard

Validate before calling

function assertPluginName(p: unknown) {
  if (!p || typeof (p as any).name !== 'string') {
    throw new Error('Plugin object must include a string `name`');
  }
}

Type guard

function hasPluginName(p: unknown): p is {name: string} {
  return typeof p === 'object' && p !== null && typeof (p as any).name === 'string';
}

Prevention

Type plugin returns as `Plugin` from `@docusaurus/types`.
Always include an explicit `name` in the returned object, not just on the function.
Add a tiny unit test asserting `name` is present for each plugin.

When it happens

Trigger: Returning `{ loadContent: ... }` without `name`; assigning the plugin object from a spread that omits `name`; an inline plugin function literal whose body returns a nameless object.

Common situations: Quick prototyping an inline plugin in docusaurus.config.js; refactoring a plugin module and dropping the `name` export; copying a snippet that omitted `name`.

Related errors

AI-assisted analysis of facebook/docusaurus@3f483e80e3 (2026-08-12). Data as JSON: /api/errors/9cb5a7be853689b5. Report an issue: GitHub.