fix(v2): codesandbox generated examples should use published init package (#3760)

* Fix codesandbox generated examples to use published init script instead of local one

* Fix codesandbox generated examples to use published init script instead of local one

generateExamples.js

@@ -0,0 +1,75 @@
+/**
+ * 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.
+ */
+
+// eslint-disable-next-line import/no-extraneous-dependencies
+const rimraf = require('rimraf');
+const {readFileSync, writeFileSync, readdir} = require('fs');
+const {execSync} = require('child_process');
+
+// Generate one example per init template
+// We use those generated examples as CodeSandbox projects
+// See https://github.com/facebook/docusaurus/issues/1699
+function generateTemplateExample(template) {
+  try {
+    console.log(
+      `generating ${template} template for codesandbox in the examples folder...`,
+    );
+
+    // run the docusaurus script to bootstrap the template in the examples folder
+    execSync(
+      // /!\ we use the published init script on purpose,
+      // because using the local init script is too early and could generate upcoming/unavailable config options
+      // remember CodeSandbox templates will use the published version, not the repo version
+      `npx @docusaurus/init@next init examples/${template} ${template}`,
+      // `node ./packages/docusaurus-init/bin/index.js init examples/${template} ${template}`,
+      {
+        stdio: 'inherit',
+      },
+    );
+
+    // read the content of the package.json
+    const templatePackageJson = JSON.parse(
+      readFileSync(`examples/${template}/package.json`, 'utf8'),
+    );
+
+    // attach the dev script which would be used in code sandbox by default
+    templatePackageJson.scripts.dev = 'docusaurus start';
+
+    // rewrite the package.json file with the new edit
+    writeFileSync(
+      `./examples/${template}/package.json`,
+      JSON.stringify(templatePackageJson, null, 2),
+    );
+
+    // create sandbox.config.json file at the root of template
+    const sandboxConfigContent = {
+      infiniteLoopProtection: true,
+      hardReloadOnChange: true,
+      view: 'browser',
+      template: 'node',
+    };
+
+    writeFileSync(
+      `./examples/${template}/sandbox.config.json`,
+      JSON.stringify(sandboxConfigContent, null, 2),
+    );
+
+    console.log(`Generated example for template ${template}`);
+  } catch (error) {
+    console.error(`Failed to generated example for template ${template}`);
+    throw error;
+  }
+}
+
+// delete the examples directory if it exists
+rimraf.sync('./examples');
+
+// get the list of all available templates
+readdir('./packages/docusaurus-init/templates', (err, data) => {
+  const templates = data.filter((i) => i !== 'README.MD');
+  templates.forEach(generateTemplateExample);
+});