fix(types): load dev server configuration types (AI-assisted)

__tests__/plugin-types.test.ts

@@ -0,0 +1,36 @@
+/**
+ * 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.
+ */
+
+import {describe, expect, it} from 'vitest';
+import {fileURLToPath} from 'node:url';
+import ts from 'typescript';
+
+describe('plugin types', () => {
+  it('supports devServer without a consumer importing webpack-dev-server', () => {
+    const fixture = fileURLToPath(
+      new URL('./__fixtures__/configureWebpack/index.ts', import.meta.url),
+    );
+    // Compile separately: other tests import webpack-dev-server, which augments
+    // webpack Configuration and would hide missing imports in our public types.
+    const program = ts.createProgram([fixture], {
+      strict: true,
+      noEmit: true,
+      skipLibCheck: true,
+      types: [],
+      target: ts.ScriptTarget.ESNext,
+      module: ts.ModuleKind.ESNext,
+      moduleResolution: ts.ModuleResolutionKind.Bundler,
+      esModuleInterop: true,
+    });
+    const diagnostics = ts
+      .getPreEmitDiagnostics(program)
+      .map((diagnostic) =>
+        ts.flattenDiagnosticMessageText(diagnostic.messageText, '\n'),
+      );
+    expect(diagnostics).toEqual([]);
+  });
+});

packages/docusaurus-types/package.json

@@ -22,6 +22,7 @@
     "mdast-util-directive": "catalog:",
     "utility-types": "catalog:",
     "webpack": "catalog:",
+    "webpack-dev-server": "catalog:",
     "webpack-merge": "catalog:"
   },
   "peerDependencies": {

packages/docusaurus-types/src/plugin.d.ts

@@ -7,6 +7,8 @@
 
 import type {CodeTranslations, TranslationFile} from './i18n';
 import type {RuleSetRule, Configuration as WebpackConfiguration} from 'webpack';
+// Load the devServer augmentation of webpack.Configuration.
+import type {} from 'webpack-dev-server';
 import type {CustomizeRuleString} from 'webpack-merge/dist/types';
 import type {Command} from 'commander';
 import type Joi from 'joi';