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

packages/create-docusaurus/bin/index.js

@@ -38,6 +38,7 @@ program
     'Do not run package manager immediately after scaffolding',
   )
   .option('-t, --typescript', 'Use the TypeScript template variant')
+  .option('-j, --javascript', 'Use the JavaScript template variant')
   .option(
     '-g, --git-strategy <strategy>',
     `Only used if the template is a git repository.

packages/create-docusaurus/src/index.ts

@@ -13,14 +13,17 @@ import logger from '@docusaurus/logger';
 import shell from 'shelljs';
 import prompts, {type Choice} from 'prompts';
 import supportsColor from 'supports-color';
-import {escapeShellArg} from '@docusaurus/utils';
+import {
+  escapeShellArg,
+  getLanguage,
+  type LanguagesOptions,
+} from '@docusaurus/utils';
 
 type CLIOptions = {
   packageManager?: PackageManager;
   skipInstall?: boolean;
-  typescript?: boolean;
   gitStrategy?: GitStrategy;
-};
+} & LanguagesOptions;
 
 // Only used in the rare, rare case of running globally installed create +
 // using --skip-install. We need a default name to show the tip text
@@ -217,6 +220,23 @@ async function getGitCommand(gitStrategy: GitStrategy): Promise<string> {
   }
 }
 
+function getTemplate(
+  templates: Template[],
+  reqTemplate?: string,
+  typescript?: boolean,
+) {
+  const template = templates.find((t) => t.name === reqTemplate);
+  if (!template) {
+    logger.error('Invalid template.');
+    process.exit(1);
+  }
+  if (typescript && !template.tsVariantPath) {
+    logger.error`Template name=${reqTemplate!} doesn't provide the TypeScript variant.`;
+    process.exit(1);
+  }
+  return template;
+}
+
 async function getSiteName(
   reqName: string | undefined,
   rootDir: string,
@@ -275,6 +295,7 @@ type Source =
 async function getSource(
   reqTemplate: string | undefined,
   templates: Template[],
+  language: LanguagesOptions,
   cliOptions: CLIOptions,
 ): Promise<Source> {
   if (reqTemplate) {
@@ -299,19 +320,13 @@ async function getSource(
         path: path.resolve(reqTemplate),
       };
     }
-    const template = templates.find((t) => t.name === reqTemplate);
-    if (!template) {
-      logger.error('Invalid template.');
-      process.exit(1);
-    }
-    if (cliOptions.typescript && !template.tsVariantPath) {
-      logger.error`Template name=${reqTemplate} doesn't provide the TypeScript variant.`;
-      process.exit(1);
-    }
+
+    const template = getTemplate(templates, reqTemplate, language.typescript);
+
     return {
       type: 'template',
       template,
-      typescript: cliOptions.typescript ?? false,
+      typescript: language.typescript ?? false,
     };
   }
   const template = cliOptions.gitStrategy
@@ -417,7 +432,8 @@ async function getSource(
       path: templateDir,
     };
   }
-  let useTS = cliOptions.typescript;
+  let useTS = language.typescript;
+
   if (!useTS && template.tsVariantPath) {
     ({useTS} = (await prompts({
       type: 'confirm',
@@ -452,7 +468,14 @@ export default async function init(
     getSiteName(reqName, rootDir),
   ]);
   const dest = path.resolve(rootDir, siteName);
-  const source = await getSource(reqTemplate, templates, cliOptions);
+  const {typescript, javascript} = cliOptions;
+  const languageOptions = {typescript, javascript};
+  const noTsVersionAvailable = !getTemplate(templates, reqTemplate, typescript)
+    .tsVariantPath;
+
+  const language = await getLanguage(languageOptions, noTsVersionAvailable);
+
+  const source = await getSource(reqTemplate, templates, language, cliOptions);
 
   logger.info('Creating new Docusaurus project...');
 

packages/docusaurus-utils/package.json

@@ -30,6 +30,7 @@
     "js-yaml": "^4.1.0",
     "lodash": "^4.17.21",
     "micromatch": "^4.0.5",
+    "prompts": "^2.4.2",
     "resolve-pathname": "^3.0.0",
     "shelljs": "^0.8.5",
     "tslib": "^2.6.0",

packages/docusaurus-utils/src/cliUtils.ts

@@ -0,0 +1,44 @@
+/**
+ * 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 from 'prompts';
+import logger from '@docusaurus/logger';
+
+export type LanguagesOptions = {
+  javascript?: boolean;
+  typescript?: boolean;
+};
+
+export async function getLanguage(
+  languages: LanguagesOptions,
+  noTsVersionAvailable?: boolean,
+): Promise<LanguagesOptions> {
+  if (languages.typescript || languages.javascript) {
+    return languages;
+  }
+  if (noTsVersionAvailable) {
+    return {javascript: true};
+  }
+  const {language: selectedLanguage} = (await prompts(
+    {
+      type: 'select',
+      name: 'language',
+      message: 'Which language do you want to use?',
+      choices: [
+        {title: 'JavaScript', value: 'javascript'},
+        {title: 'TypeScript', value: 'typescript'},
+      ],
+    },
+    {
+      onCancel() {
+        logger.info`Falling back to language=${'javascript'}`;
+      },
+    },
+  )) as {language: keyof LanguagesOptions};
+
+  return {[selectedLanguage]: true};
+}

packages/docusaurus-utils/src/index.ts

@@ -110,3 +110,4 @@ export {
 } from './dataFileUtils';
 export {isDraft, isUnlisted} from './contentVisibilityUtils';
 export {escapeRegexp} from './regExpUtils';
+export {getLanguage, type LanguagesOptions} from './cliUtils';