feat(create-docusaurus): ask user for preferred language when no language CLI option provided (#9442)

Co-authored-by: sebastien <lorber.sebastien@gmail.com>

packages/docusaurus-utils/src/cliUtils.ts

@@ -0,0 +1,65 @@
+/**
+ * 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 prompts, {type Choice} from 'prompts';
+import logger from '@docusaurus/logger';
+
+type PreferredLanguage = 'javascript' | 'typescript';
+
+type AskPreferredLanguageOptions = {
+  fallback: PreferredLanguage | undefined;
+  exit: boolean;
+};
+
+const DefaultOptions: AskPreferredLanguageOptions = {
+  fallback: undefined,
+  exit: false,
+};
+
+const ExitChoice: Choice = {title: logger.yellow('[Exit]'), value: '[Exit]'};
+
+export async function askPreferredLanguage(
+  options: Partial<AskPreferredLanguageOptions> = {},
+): Promise<'javascript' | 'typescript'> {
+  const {fallback, exit} = {...DefaultOptions, ...options};
+
+  const choices: Choice[] = [
+    {title: logger.bold('JavaScript'), value: 'javascript'},
+    {title: logger.bold('TypeScript'), value: 'typescript'},
+  ];
+  if (exit) {
+    choices.push(ExitChoice);
+  }
+
+  const {language} = await prompts(
+    {
+      type: 'select',
+      name: 'language',
+      message: 'Which language do you want to use?',
+      choices,
+    },
+    {
+      onCancel() {
+        exit && process.exit(0);
+      },
+    },
+  );
+
+  if (language === ExitChoice.value) {
+    process.exit(0);
+  }
+
+  if (!language) {
+    if (fallback) {
+      logger.info`Falling back to language=${fallback}`;
+      return fallback;
+    }
+    process.exit(0);
+  }
+
+  return language;
+}

packages/docusaurus-utils/src/index.ts

@@ -117,3 +117,4 @@ export {
 } from './dataFileUtils';
 export {isDraft, isUnlisted} from './contentVisibilityUtils';
 export {escapeRegexp} from './regExpUtils';
+export {askPreferredLanguage} from './cliUtils';