fix(core): fail fast if plugin has no name (#10239)

packages/docusaurus/src/server/plugins/__tests__/__fixtures__/site-with-unnamed-plugin/docusaurus.config.js

@@ -0,0 +1,19 @@
+/**
+ * Copyright (c) Facebook, Inc. and its affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+
+module.exports = {
+  title: 'My Site',
+  tagline: 'The tagline of my site',
+  url: 'https://your-docusaurus-site.example.com',
+  baseUrl: '/',
+  favicon: 'img/favicon.ico',
+  plugins: [
+    function (context, options) {
+      return {noname: 'on-purpose'};
+    },
+  ],
+};

packages/docusaurus/src/server/plugins/__tests__/__snapshots__/init.test.ts.snap

@@ -1,29 +0,0 @@
-// Jest Snapshot v1, https://goo.gl/fbAQLP
-
-exports[`initPlugins throws user-friendly error message for plugins with bad values 1`] = `
-" => Bad Docusaurus plugin value plugins[0].
-Example valid plugin config:
-{
-  plugins: [
-    ["@docusaurus/plugin-content-docs",options],
-    "./myPlugin",
-    ["./myPlugin",{someOption: 42}],
-    function myPlugin() { },
-    [function myPlugin() { },options]
-  ],
-};
-
- => Bad Docusaurus plugin value plugins[1].
-Example valid plugin config:
-{
-  plugins: [
-    ["@docusaurus/plugin-content-docs",options],
-    "./myPlugin",
-    ["./myPlugin",{someOption: 42}],
-    function myPlugin() { },
-    [function myPlugin() { },options]
-  ],
-};
-
-"
-`;

packages/docusaurus/src/server/plugins/__tests__/init.test.ts

@@ -10,17 +10,20 @@ import path from 'path';
 import {loadContext, type LoadContextParams} from '../../site';
 import {initPlugins} from '../init';
 
+async function loadSite(
+  fixtureName: string,
+  options: Omit<LoadContextParams, 'siteDir'> = {},
+) {
+  const siteDir = path.join(__dirname, '__fixtures__', fixtureName);
+  const context = await loadContext({...options, siteDir});
+  const plugins = await initPlugins(context);
+
+  return {siteDir, context, plugins};
+}
+
 describe('initPlugins', () => {
-  async function loadSite(options: Omit<LoadContextParams, 'siteDir'> = {}) {
-    const siteDir = path.join(__dirname, '__fixtures__', 'site-with-plugin');
-    const context = await loadContext({...options, siteDir});
-    const plugins = await initPlugins(context);
-
-    return {siteDir, context, plugins};
-  }
-
   it('parses plugins correctly and loads them in correct order', async () => {
-    const {context, plugins} = await loadSite();
+    const {context, plugins} = await loadSite('site-with-plugin');
     expect(context.siteConfig.plugins).toHaveLength(6);
     expect(plugins).toHaveLength(10);
 
@@ -45,7 +48,41 @@ describe('initPlugins', () => {
 
   it('throws user-friendly error message for plugins with bad values', async () => {
     await expect(() =>
-      loadSite({config: 'badPlugins.docusaurus.config.js'}),
+      loadSite('site-with-plugin', {config: 'badPlugins.docusaurus.config.js'}),
-    ).rejects.toThrowErrorMatchingSnapshot();
+    ).rejects.toThrowErrorMatchingInlineSnapshot(`
+      " => Bad Docusaurus plugin value plugins[0].
+      Example valid plugin config:
+      {
+        plugins: [
+          ["@docusaurus/plugin-content-docs",options],
+          "./myPlugin",
+          ["./myPlugin",{someOption: 42}],
+          function myPlugin() { },
+          [function myPlugin() { },options]
+        ],
+      };
+
+       => Bad Docusaurus plugin value plugins[1].
+      Example valid plugin config:
+      {
+        plugins: [
+          ["@docusaurus/plugin-content-docs",options],
+          "./myPlugin",
+          ["./myPlugin",{someOption: 42}],
+          function myPlugin() { },
+          [function myPlugin() { },options]
+        ],
+      };
+
+      "
+    `);
+  });
+
+  it('throws user-friendly error message for plugins with no name', async () => {
+    await expect(() => loadSite('site-with-unnamed-plugin')).rejects
+      .toThrowErrorMatchingInlineSnapshot(`
+      "A Docusaurus plugin is missing a 'name' property.
+      Note that even inline/anonymous plugin functions require a 'name' property."
+    `);
   });
 });

packages/docusaurus/src/server/plugins/init.ts

@@ -125,6 +125,13 @@ export async function initPlugins(
       pluginOptions,
     );
 
+    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.`,
+      );
+    }
+
     return {
       ...pluginInstance,
       options: pluginOptions,