Add extension settings to be requested on install (#9802)

packages/cli/src/config/extensions/extensionSettings.ts

@@ -0,0 +1,96 @@
+/**
+ * @license
+ * Copyright 2025 Google LLC
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+import * as fs from 'node:fs/promises';
+import * as fsSync from 'node:fs';
+import * as dotenv from 'dotenv';
+
+import { ExtensionStorage } from '../extension.js';
+import type { ExtensionConfig } from '../extension.js';
+
+import prompts from 'prompts';
+
+export interface ExtensionSetting {
+  name: string;
+  description: string;
+  envVar: string;
+}
+
+export async function maybePromptForSettings(
+  extensionConfig: ExtensionConfig,
+  requestSetting: (setting: ExtensionSetting) => Promise<string>,
+  previousExtensionConfig?: ExtensionConfig,
+  previousSettings?: Record<string, string>,
+): Promise<void> {
+  const { name: extensionName, settings } = extensionConfig;
+  const envFilePath = new ExtensionStorage(extensionName).getEnvFilePath();
+
+  if (!settings || settings.length === 0) {
+    // No settings for this extension. Clear any existing .env file.
+    if (fsSync.existsSync(envFilePath)) {
+      await fs.writeFile(envFilePath, '');
+    }
+    return;
+  }
+
+  let settingsToPrompt = settings;
+  if (previousExtensionConfig) {
+    const oldSettings = new Set(
+      previousExtensionConfig.settings?.map((s) => s.name) || [],
+    );
+    settingsToPrompt = settingsToPrompt.filter((s) => !oldSettings.has(s.name));
+  }
+
+  const allSettings: Record<string, string> = { ...(previousSettings ?? {}) };
+
+  if (settingsToPrompt && settingsToPrompt.length > 0) {
+    for (const setting of settingsToPrompt) {
+      const answer = await requestSetting(setting);
+      allSettings[setting.envVar] = answer;
+    }
+  }
+
+  const validEnvVars = new Set(settings.map((s) => s.envVar));
+  const finalSettings: Record<string, string> = {};
+  for (const [key, value] of Object.entries(allSettings)) {
+    if (validEnvVars.has(key)) {
+      finalSettings[key] = value;
+    }
+  }
+
+  let envContent = '';
+  for (const [key, value] of Object.entries(finalSettings)) {
+    envContent += `${key}=${value}\n`;
+  }
+
+  await fs.writeFile(envFilePath, envContent);
+}
+
+export async function promptForSetting(
+  setting: ExtensionSetting,
+): Promise<string> {
+  const response = await prompts({
+    // type: setting.sensitive ? 'password' : 'text',
+    type: 'text',
+    name: 'value',
+    message: `${setting.name}\n${setting.description}`,
+  });
+  return response.value;
+}
+
+export function getEnvContents(
+  extensionStorage: ExtensionStorage,
+): Record<string, string> {
+  let customEnv: Record<string, string> = {};
+  if (fsSync.existsSync(extensionStorage.getEnvFilePath())) {
+    const envFile = fsSync.readFileSync(
+      extensionStorage.getEnvFilePath(),
+      'utf-8',
+    );
+    customEnv = dotenv.parse(envFile);
+  }
+  return customEnv;
+}