Make emulators:exec exit with non-zero code when script fails (#1387)

changelog.txt

@@ -3,3 +3,4 @@
 * Fixes bug in Firestore emulator where property paths with special characters would cause errors due to ClassNotFound exceptions.
 * Fixes bug in Firestore emulator where auto-id allocation only worked once per collection.
 * Adds REST API to Firestore emulator for setting security rules.
+* Fixes bug where `firebase emulators:exec` would succeed even if the script failed.

src/commands/emulators-exec.ts

@@ -7,13 +7,14 @@ import getProjectNumber = require("../getProjectNumber");
 import requireAuth = require("../requireAuth");
 import requireConfig = require("../requireConfig");
 import { Emulators } from "../emulator/types";
+import * as FirebaseError from "../error";
 import * as utils from "../utils";
 import * as logger from "../logger";
 import * as controller from "../emulator/controller";
 import { EmulatorRegistry } from "../emulator/registry";
 import { FirestoreEmulator } from "../emulator/firestoreEmulator";
 
-async function runScript(script: string): Promise<void> {
+async function runScript(script: string): Promise<number> {
   utils.logBullet(`Running script: ${clc.bold(script)}`);
 
   const env: NodeJS.ProcessEnv = { ...process.env };
@@ -52,15 +53,19 @@ async function runScript(script: string): Promise<void> {
       if (signal) {
         utils.logWarning(`Script exited with signal: ${signal}`);
         setTimeout(reject, exitDelayMs);
+        return;
       }
 
+      const exitCode = code || 0;
       if (code === 0) {
         utils.logSuccess(`Script exited successfully (code 0)`);
-        setTimeout(resolve, exitDelayMs);
       } else {
         utils.logWarning(`Script exited unsuccessfully (code ${code})`);
-        setTimeout(resolve, exitDelayMs);
       }
+
+      setTimeout(() => {
+        resolve(exitCode);
+      }, exitDelayMs);
     });
   });
 }
@@ -82,13 +87,20 @@ module.exports = new Command("emulators:exec <script>")
       JSON.stringify(controller.VALID_EMULATOR_STRINGS)
   )
   .action(async (script: string, options: any) => {
+    let exitCode = 0;
     try {
       await controller.startAll(options);
-      await runScript(script);
+      exitCode = await runScript(script);
     } catch (e) {
       logger.debug("Error in emulators:exec", e);
       throw e;
     } finally {
       await controller.cleanShutdown();
     }
+
+    if (exitCode !== 0) {
+      throw new FirebaseError(`Script "${clc.bold(script)}" exited with code ${exitCode}`, {
+        exit: exitCode,
+      });
+    }
   });