Fixes Storage Emulator startup errors

CHANGELOG.md

@@ -3,3 +3,4 @@
 - Fixes `firebase init database` failure when no project is selected (#2981)
 - Fix issue where `firebase init database` overwrites entire `firebase.json` (#3299)
 - Fixes import/export bug with Storage emulator download tokens (#3414)
+- Improves errors when failing to start Storage emulator (#3443)

src/emulator/downloadableEmulators.ts

@@ -253,15 +253,15 @@ export function _getCommand(
   };
 }
 
-async function _fatal(emulator: DownloadableEmulatorDetails, errorMsg: string): Promise<void> {
+async function _fatal(emulator: Emulators, errorMsg: string): Promise<void> {
   // if we do not issue a stopAll here and _fatal is called during startup, we could leave emulators running
   // that did start already
   // for example: JAVA_HOME=/does/not/exist firebase emulators:start
   try {
-    const logger = EmulatorLogger.forEmulator(emulator.name);
+    const logger = EmulatorLogger.forEmulator(emulator);
     logger.logLabeled(
       "WARN",
-      emulator.name,
+      emulator,
       `Fatal error occurred: \n   ${errorMsg}, \n   stopping all running emulators`
     );
     await EmulatorRegistry.stopAll();
@@ -270,6 +270,18 @@ async function _fatal(emulator: DownloadableEmulatorDetails, errorMsg: string):
   }
 }
 
+export async function handleEmulatorProcessError(emulator: Emulators, err: any): Promise<void> {
+  const description = Constants.description(emulator);
+  if (err.path === "java" && err.code === "ENOENT") {
+    await _fatal(
+      emulator,
+      `${description} has exited because java is not installed, you can install it from https://openjdk.java.net/install/`
+    );
+  } else {
+    await _fatal(emulator, `${description} has exited: ${err}`);
+  }
+}
+
 async function _runBinary(
   emulator: DownloadableEmulatorDetails,
   command: DownloadableEmulatorCommand,
@@ -298,7 +310,7 @@ async function _runBinary(
           `Could not spawn child process for emulator, check that java is installed and on your $PATH.`
         );
       }
-      _fatal(emulator, e);
+      _fatal(emulator.name, e);
     }
 
     const description = Constants.description(emulator.name);
@@ -331,21 +343,15 @@ async function _runBinary(
       }
     });
 
-    emulator.instance.on("error", async (err: any) => {
-      if (err.path === "java" && err.code === "ENOENT") {
-        await _fatal(
-          emulator,
-          `${description} has exited because java is not installed, you can install it from https://openjdk.java.net/install/`
-        );
-      } else {
-        await _fatal(emulator, `${description} has exited: ${err}`);
-      }
+    emulator.instance.on("error", (err) => {
+      handleEmulatorProcessError(emulator.name, err);
     });
+
     emulator.instance.once("exit", async (code, signal) => {
       if (signal) {
         utils.logWarning(`${description} has exited upon receiving signal: ${signal}`);
       } else if (code && code !== 0 && code !== /* SIGINT */ 130) {
-        await _fatal(emulator, `${description} has exited with code: ${code}`);
+        await _fatal(emulator.name, `${description} has exited with code: ${code}`);
       }
     });
     resolve();

src/emulator/storage/rules/runtime.ts

@@ -21,7 +21,11 @@ import * as utils from "../../../utils";
 import { Constants } from "../../constants";
 import { downloadEmulator } from "../../download";
 import * as fs from "fs-extra";
-import { DownloadDetails, _getCommand } from "../../downloadableEmulators";
+import {
+  _getCommand,
+  DownloadDetails,
+  handleEmulatorProcessError,
+} from "../../downloadableEmulators";
 
 export interface RulesetVerificationOpts {
   file: {
@@ -142,16 +146,22 @@ export class StorageRulesRuntime {
       };
     });
 
+    // This catches error when spawning the java process
+    this._childprocess.on("error", (err) => {
+      handleEmulatorProcessError(Emulators.STORAGE, err);
+    });
+
+    // This catches errors from the java process (i.e. missing jar file)
     this._childprocess.stderr.on("data", (buf: Buffer) => {
       const error = buf.toString();
-      if (error.includes("Invalid or corrupt jarfile")) {
+      if (error.includes("jarfile")) {
         throw new FirebaseError(
           "There was an issue starting the rules emulator, please run 'firebase setup:emulators:storage` again"
         );
       } else {
         EmulatorLogger.forEmulator(Emulators.STORAGE).log(
           "WARN",
-          `Unexpected rules runtime output: ${buf.toString()}`
+          `Unexpected rules runtime error: ${buf.toString()}`
         );
       }
     });