Implement support for demo project ID namespace

CHANGELOG.md

@@ -1 +1,2 @@
 - Include `appId` in web app configuration when using the Hosting emulator (#2798).
+- Add support for emulating the `demo-*` project ID namespace with fake Admin and Web SDK configurations (#3291).

src/emulator/adminSdkConfig.ts

@@ -3,6 +3,7 @@ import * as apiv2 from "../apiv2";
 import { configstore } from "../configstore";
 import { FirebaseError } from "../error";
 import { logger } from "../logger";
+import { Constants } from "./constants";
 
 export type AdminSdkConfig = {
   projectId: string;
@@ -33,6 +34,11 @@ export function constructDefaultAdminSdkConfig(projectId: string): AdminSdkConfi
 export async function getProjectAdminSdkConfigOrCached(
   projectId: string
 ): Promise<AdminSdkConfig | undefined> {
+  // When using the emulators with a fake project Id, use a fake project config.
+  if (Constants.isDemoProject(projectId)) {
+    return constructDefaultAdminSdkConfig(projectId);
+  }
+
   try {
     const config = await getProjectAdminSdkConfig(projectId);
     setCacheAdminSdkConfig(projectId, config);
@@ -46,7 +52,7 @@ export async function getProjectAdminSdkConfigOrCached(
 /**
  * Gets the Admin SDK configuration associated with a project.
  */
-export async function getProjectAdminSdkConfig(projectId: string): Promise<AdminSdkConfig> {
+async function getProjectAdminSdkConfig(projectId: string): Promise<AdminSdkConfig> {
   const apiClient = new apiv2.Client({
     auth: true,
     apiVersion: "v1beta1",

src/emulator/constants.ts

@@ -44,6 +44,10 @@ export const EMULATOR_DESCRIPTION: Record<Emulators, string> = {
 const DEFAULT_HOST = "localhost";
 
 export class Constants {
+  // GCP projects cannot start with 'demo' so we use 'demo-' as a prefix to denote
+  // an intentionally fake project.
+  static FAKE_PROJECT_ID_PREFIX = "demo-";
+
   static DEFAULT_DATABASE_EMULATOR_NAMESPACE = "fake-server";
 
   // Environment variable to override SDK/CLI to point at the Firestore emulator.
@@ -124,4 +128,8 @@ export class Constants {
     const u = url.parse(normalized);
     return u.hostname || DEFAULT_HOST;
   }
+
+  static isDemoProject(projectId?: string): boolean {
+    return !!projectId && projectId.startsWith(this.FAKE_PROJECT_ID_PREFIX);
+  }
 }

src/emulator/controller.ts

@@ -327,19 +327,23 @@ export async function startAll(options: any, showUI: boolean = true): Promise<vo
   const targets = filterEmulatorTargets(options);
   options.targets = targets;
 
-  const projectId: string | undefined = getProjectId(options, true);
-
   if (targets.length === 0) {
     throw new FirebaseError(
       `No emulators to start, run ${clc.bold("firebase init emulators")} to get started.`
     );
   }
+  const hubLogger = EmulatorLogger.forEmulator(Emulators.HUB);
+  hubLogger.logLabeled("BULLET", "emulators", `Starting emulators: ${targets.join(", ")}`);
+
+  const projectId: string | undefined = getProjectId(options, true);
+  if (Constants.isDemoProject(projectId)) {
+    hubLogger.logLabeled(
+      "BULLET",
+      "emulators",
+      `Detected demo project ID "${projectId}", emulated services will use a demo configuration and attempts to access non-emulated services for this project will fail.`
+    );
+  }
 
-  EmulatorLogger.forEmulator(Emulators.HUB).logLabeled(
-    "BULLET",
-    "emulators",
-    `Starting emulators: ${targets.join(", ")}`
-  );
   const onlyOptions: string = options.only;
   if (onlyOptions) {
     const requested: string[] = onlyOptions.split(",").map((o) => {
@@ -385,7 +389,7 @@ export async function startAll(options: any, showUI: boolean = true): Promise<vo
     if (foundMetadata) {
       exportMetadata = foundMetadata;
     } else {
-      EmulatorLogger.forEmulator(Emulators.HUB).logLabeled(
+      hubLogger.logLabeled(
         "WARN",
         "emulators",
         `Could not find import/export metadata file, ${clc.bold("skipping data import!")}`
@@ -418,7 +422,7 @@ export async function startAll(options: any, showUI: boolean = true): Promise<vo
     const emulatorsNotRunning = ALL_SERVICE_EMULATORS.filter((e) => {
       return e !== Emulators.FUNCTIONS && !shouldStart(options, e);
     });
-    if (emulatorsNotRunning.length > 0) {
+    if (emulatorsNotRunning.length > 0 && !Constants.isDemoProject(projectId)) {
       functionsLogger.logLabeled(
         "WARN",
         "functions",
@@ -652,7 +656,7 @@ export async function startAll(options: any, showUI: boolean = true): Promise<vo
   }
 
   if (showUI && !shouldStart(options, Emulators.UI)) {
-    EmulatorLogger.forEmulator(Emulators.HUB).logLabeled(
+    hubLogger.logLabeled(
       "WARN",
       "emulators",
       "The Emulator UI requires a project ID to start. Configure your default project with 'firebase use' or pass the --project flag."

src/fetchWebSetup.ts

@@ -3,6 +3,7 @@ import { configstore } from "./configstore";
 import { firebaseApiOrigin, hostingApiOrigin } from "./api";
 import * as getProjectId from "./getProjectId";
 import { logger } from "./logger";
+import { Constants } from "./emulator/constants";
 
 export interface WebConfig {
   projectId: string;
@@ -76,6 +77,19 @@ async function listAllSites(projectId: string, nextPageToken?: string): Promise<
   return sites;
 }
 
+/**
+ * Construct a fake configuration based on the project ID.
+ */
+function constructDefaultWebSetup(projectId: string): WebConfig {
+  return {
+    projectId,
+    databaseURL: `https://${projectId}.firebaseio.com`,
+    storageBucket: `${projectId}.appspot.com`,
+    apiKey: "fake-api-key",
+    authDomain: `${projectId}.firebaseapp.com`,
+  };
+}
+
 /**
  * TODO: deprecate this function in favor of `getAppConfig()` in `/src/management/apps.ts`
  * @param options CLI options.
@@ -84,6 +98,11 @@ async function listAllSites(projectId: string, nextPageToken?: string): Promise<
 export async function fetchWebSetup(options: any): Promise<WebConfig> {
   const projectId = getProjectId(options, false);
 
+  // When using the emulators with a fake project ID, use a fake web config
+  if (Constants.isDemoProject(projectId)) {
+    return constructDefaultWebSetup(projectId);
+  }
+
   // Try to determine the appId from the default Hosting site, if it is linked.
   let hostingAppId: string | undefined = undefined;
   try {

src/test/emulators/adminSdkConfig.test.ts

@@ -0,0 +1,15 @@
+import { expect } from "chai";
+import { getProjectAdminSdkConfigOrCached } from "../../emulator/adminSdkConfig";
+
+describe("adminSdkConfig", () => {
+  describe("getProjectAdminSdkConfigOrCached", () => {
+    it("should return a fake config for a demo project id", async () => {
+      const projectId = "demo-project-1234";
+      await expect(getProjectAdminSdkConfigOrCached(projectId)).to.eventually.deep.equal({
+        projectId: "demo-project-1234",
+        databaseURL: "https://demo-project-1234.firebaseio.com",
+        storageBucket: "demo-project-1234.appspot.com",
+      });
+    });
+  });
+});

src/test/fetchWebSetup.spec.ts

@@ -63,6 +63,17 @@ describe("fetchWebSetup module", () => {
         "Not Found"
       );
     });
+
+    it("should return a fake config for a demo project id", async () => {
+      const projectId = "demo-project-1234";
+      await expect(fetchWebSetup({ project: projectId })).to.eventually.deep.equal({
+        projectId: "demo-project-1234",
+        databaseURL: "https://demo-project-1234.firebaseio.com",
+        storageBucket: "demo-project-1234.appspot.com",
+        apiKey: "fake-api-key",
+        authDomain: "demo-project-1234.firebaseapp.com",
+      });
+    });
   });
 
   describe("getCachedWebSetup", () => {