Apply rules to the correct emulated RTDB instance (#3146)

CHANGELOG.md

@@ -1 +1,2 @@
 - Fixes issue where OOB flow is not initiated after updating a user's email (#3096)
+- Fixes issue where rules are not applied to the default emulated Realtime Database instance (#3124)

src/database/rulesConfig.ts

@@ -41,7 +41,8 @@ export function getRulesConfig(projectId: string, options: any): RulesInstanceCo
 
   if (!Array.isArray(dbConfig)) {
     if (dbConfig && dbConfig.rules) {
-      return [{ rules: dbConfig.rules, instance: options.instance || options.project }];
+      const instance = options.instance || `${options.project}-default-rtdb`;
+      return [{ rules: dbConfig.rules, instance }];
     } else {
       logger.debug("Possibly invalid database config: ", JSON.stringify(dbConfig));
       return [];

src/emulator/controller.ts

@@ -39,6 +39,7 @@ import { promptOnce } from "../prompt";
 import * as rimraf from "rimraf";
 import { FLAG_EXPORT_ON_EXIT_NAME } from "./commandUtils";
 import { fileExistsSync } from "../fsutils";
+import { getDefaultDatabaseInstance } from "../getDefaultDatabaseInstance";
 
 async function getAndCheckAddress(emulator: Emulators, options: any): Promise<Address> {
   let host = Constants.normalizeHost(
@@ -494,6 +495,19 @@ export async function startAll(options: any, showUI: boolean = true): Promise<vo
       auto_download: true,
     };
 
+    // Try to fetch the default RTDB instance for a project, but don't hard-fail if we
+    // can't because the user may be using a fake project.
+    try {
+      if (!options.instance) {
+        options.instance = await getDefaultDatabaseInstance(options);
+      }
+    } catch (e) {
+      databaseLogger.log(
+        "DEBUG",
+        `Failed to retrieve default database instance: ${JSON.stringify(e)}`
+      );
+    }
+
     const rc = dbRulesConfig.normalizeRulesConfig(
       dbRulesConfig.getRulesConfig(projectId, options),
       options