[FDC] Provide flutter as an option during init dataconnect

CHANGELOG.md

@@ -1 +1,2 @@
-- `firebase emulator:start` use a default project if no project can be found. (#9072)
+- `firebase emulator:start` use a default project `demo-no-project` if no project can be found. (#9072)
+- `firebase init dataconnect` also supports bootstrapping flutter template. (#9084)

src/init/features/dataconnect/create_app.ts

@@ -26,9 +26,15 @@
   await executeCommand("npx", args);
 }
 
+/** Create a Flutter app using flutter create. */
+export async function createFlutterApp(webAppId: string): Promise<void> {
+  const args = ["create", webAppId];
+  await executeCommand("flutter", args);
+}
+
 // Function to execute a command asynchronously and pipe I/O
 async function executeCommand(command: string, args: string[]): Promise<void> {
-  logLabeledBullet("dataconnect", `Running ${clc.bold(`${command} ${args.join(" ")}`)}`);
+  logLabeledBullet("dataconnect", `> ${clc.bold(`${command} ${args.join(" ")}`)}`);
   return new Promise((resolve, reject) => {
     // spawn returns a ChildProcess object
     const childProcess = spawn(command, args, {
@@ -44,7 +50,7 @@
         resolve();
       } else {
         // Command failed
         reject(new Error(`Command failed with exit code ${code}`));
       }
     });
 

src/init/features/dataconnect/sdk.ts

@@ -28,10 +28,11 @@
   logLabeledWarning,
   logLabeledBullet,
   newUniqueId,
+  commandExistsSync,
 } from "../../../utils";
 import { DataConnectEmulator } from "../../../emulator/dataconnectEmulator";
 import { getGlobalDefaultAccount } from "../../../auth";
-import { createNextApp, createReactApp } from "./create_app";
+import { createFlutterApp, createNextApp, createReactApp } from "./create_app";
 import { trackGA4 } from "../../../track";
 import { dirExistsSync, listFiles } from "../../../fsutils";
 
@@ -49,32 +50,39 @@
   displayIOSWarning: boolean;
 };
 
 export async function askQuestions(setup: Setup): Promise<void> {
   const info: SdkRequiredInfo = {
     apps: [],
   };
 
   info.apps = await chooseApp();
   if (!info.apps.length) {
-    // By default, create an React web app.
-    const existingFilesAndDirs = listFiles(cwd);
-    const webAppId = newUniqueId("web-app", existingFilesAndDirs);
+    const npxMissingWarning = commandExistsSync("npx")
+      ? ""
+      : clc.yellow(" (you need to install Node.js first)");
+    const flutterMissingWarning = commandExistsSync("flutter")
+      ? ""
+      : clc.yellow(" (you need to install Flutter first)");
+
     const choice = await select({
       message: `Do you want to create an app template?`,
       choices: [
         // TODO: Create template tailored to FDC.
-        { name: "React", value: "react" },
-        { name: "Next.JS", value: "next" },
-        // TODO: Add flutter here.
+        { name: `React${npxMissingWarning}`, value: "react" },
+        { name: `Next.JS${npxMissingWarning}`, value: "next" },
+        { name: `Flutter${flutterMissingWarning}`, value: "flutter" },
         { name: "no", value: "no" },
       ],
     });
     switch (choice) {
       case "react":
-        await createReactApp(webAppId);
+        await createReactApp(newUniqueId("web-app", listFiles(cwd)));
         break;
       case "next":
-        await createNextApp(webAppId);
+        await createNextApp(newUniqueId("web-app", listFiles(cwd)));
+        break;
+      case "flutter":
+        await createFlutterApp(newUniqueId("flutter_app", listFiles(cwd)));
         break;
       case "no":
         break;
@@ -141,7 +149,7 @@
   return apps;
 }
 
 export async function actuate(setup: Setup, config: Config) {
   const fdcInfo = setup.featureInfo?.dataconnect;
   const sdkInfo = setup.featureInfo?.dataconnectSdk;
   if (!sdkInfo) {
@@ -166,7 +174,7 @@
   }
 }
 
 async function actuateWithInfo(setup: Setup, config: Config, info: SdkRequiredInfo) {
   if (!info.apps.length) {
     // If no apps is specified, try to detect it again.
     // In `firebase init dataconnect:sdk`, customer may create the app while the command is running.
@@ -241,7 +249,7 @@
  * and short-circuit the prompt.
  *
  * `FDC_CONNECTOR` should have the same `<location>/<serviceId>/<connectorId>`.
  * @param choices
  */
 async function chooseExistingConnector(setup: Setup, config: Config): Promise<ConnectorInfo> {
   const serviceInfos = await loadAll(setup.projectId || "", config);

src/mcp/errors.ts

@@ -1,12 +1,13 @@
 import { CallToolResult } from "@modelcontextprotocol/sdk/types.js";
-import { commandExistsSync, mcpError } from "./util";
+import { mcpError } from "./util";
+import { commandExistsSync } from "../utils";
 
 export const NO_PROJECT_ERROR = mcpError(
   'No active project was found. Use the `firebase_update_environment` tool to set the project directory to an absolute folder location containing a firebase.json config file. Alternatively, change the MCP server config to add [...,"--dir","/absolute/path/to/project/directory"] in its command-line arguments.',
   "PRECONDITION_FAILED",
 );
 
 export function mcpAuthError(skipADC: boolean): CallToolResult {
   const cmd = commandExistsSync("firebase") ? "firebase" : "npx -y firebase-tools";
   if (skipADC) {
     return mcpError(`The user is not currently logged into the Firebase CLI, which is required to use this tool. Please instruct the user to execute this shell command to sign in.
@@ -22,7 +23,7 @@
 [ADC]: https://cloud.google.com/docs/authentication/application-default-credentials`);
 }
 
 export function mcpGeminiError(projectId: string) {
   const consoleUrl = `https://firebase.corp.google.com/project/${projectId}/overview`;
   return mcpError(
     `This tool uses the Gemini in Firebase API. Visit Firebase Console to enable the Gemini in Firebase API ${consoleUrl} and try again.`,

src/mcp/index.ts

@@ -183,7 +183,7 @@ export class FirebaseMcpServer {
   }
 
   async getEmulatorHubClient(): Promise<EmulatorHubClient | undefined> {
-    // Single initilization
+    // Single initialization
     if (this.emulatorHubClient) {
       return this.emulatorHubClient;
     }

src/mcp/util.ts

@@ -1,7 +1,5 @@
 import { CallToolResult } from "@modelcontextprotocol/sdk/types.js";
-import { execSync } from "child_process";
 import { dump } from "js-yaml";
-import { platform } from "os";
 import { ServerFeature } from "./types";
 import {
   apphostingOrigin,
@@ -64,28 +62,6 @@ export function mcpError(message: Error | string | unknown, code?: string): Call
  * Wraps a throwing function with a safe conversion to mcpError.
  */
 
-/**
- * Checks if a command exists in the system.
- */
-export function commandExistsSync(command: string): boolean {
-  try {
-    const isWindows = platform() === "win32";
-    // For Windows, `where` is more appropriate. It also often outputs the path.
-    // For Unix-like systems, `which` is standard.
-    // The `2> nul` (Windows) or `2>/dev/null` (Unix) redirects stderr to suppress error messages.
-    // The `>` nul / `>/dev/null` redirects stdout as we only care about the exit code.
-    const commandToCheck = isWindows
-      ? `where "${command}" > nul 2> nul`
-      : `which "${command}" > /dev/null 2> /dev/null`;
-
-    execSync(commandToCheck);
-    return true; // If execSync doesn't throw, the command was found (exit code 0)
-  } catch (error) {
-    // If the command is not found, execSync will throw an error (non-zero exit code)
-    return false;
-  }
-}
-
 const SERVER_FEATURE_APIS: Record<ServerFeature, string> = {
   core: "",
   firestore: firestoreOrigin(),

src/utils.ts

@@ -25,6 +25,8 @@ import { readTemplateSync } from "./templates";
 import { isVSCodeExtension } from "./vsCodeUtils";
 import { Config } from "./config";
 import { dirExistsSync, fileExistsSync } from "./fsutils";
+import { platform } from "node:os";
+import { execSync } from "node:child_process";
 export const IS_WINDOWS = process.platform === "win32";
 const SUCCESS_CHAR = IS_WINDOWS ? "+" : "✔";
 const WARNING_CHAR = IS_WINDOWS ? "!" : "⚠";
@@ -1006,3 +1008,25 @@ export function newUniqueId(recommended: string, existingIDs: string[]): string
   }
   return id;
 }
+
+/**
+ * Checks if a command exists in the system.
+ */
+export function commandExistsSync(command: string): boolean {
+  try {
+    const isWindows = platform() === "win32";
+    // For Windows, `where` is more appropriate. It also often outputs the path.
+    // For Unix-like systems, `which` is standard.
+    // The `2> nul` (Windows) or `2>/dev/null` (Unix) redirects stderr to suppress error messages.
+    // The `>` nul / `>/dev/null` redirects stdout as we only care about the exit code.
+    const commandToCheck = isWindows
+      ? `where "${command}" > nul 2> nul`
+      : `which "${command}" > /dev/null 2> /dev/null`;
+
+    execSync(commandToCheck);
+    return true; // If execSync doesn't throw, the command was found (exit code 0)
+  } catch (error) {
+    // If the command is not found, execSync will throw an error (non-zero exit code)
+    return false;
+  }
+}