Force localhost for Expo iOS dogfooding

Author: niemyjski

.agents/skills/exceptionless-javascript/references/client-react-native.md

@@ -52,7 +52,7 @@ await Exceptionless.startup((config) => {
 });
 ```
 
-For local simulator development, prefer `http://localhost:<port>` when the app is running in the iOS simulator. Use a LAN IP only when a physical device must reach a server on the development machine.
+For local simulator development, prefer `http://localhost:<port>` when the app is running in the iOS simulator. Start Expo with `--localhost` or set `REACT_NATIVE_PACKAGER_HOSTNAME=localhost` so Metro bundle URLs in stack traces also use localhost. Use a LAN IP only when a physical device must reach a server on the development machine.
 
 ## Error Boundary
 
@@ -105,7 +105,7 @@ await Exceptionless.createException(new Error("Checkout failed"))
 ## Troubleshooting
 
 - If native crashes do not appear in Expo, verify the app is not running in Expo Go and that the config plugin is present before rebuilding the native app.
-- If simulator submissions cannot reach a local Exceptionless server, use `http://localhost:<port>` for iOS Simulator. Physical devices need a reachable LAN host.
+- If simulator submissions cannot reach a local Exceptionless server, use `http://localhost:<port>` for iOS Simulator and make sure Metro is not running in Expo's default LAN mode. Physical devices need a reachable LAN host.
 - For malformed or unexpected stacks, verify behavior in `ReactNativeErrorPlugin` tests before changing parser logic.
 - For native crash report loss concerns, verify `NativeCrashPlugin` only clears pending reports after at least one report is retrieved and submitted.
 

example/expo/App.tsx

@@ -31,18 +31,17 @@ function TabIcon({ label, focused }: { label: string; focused: boolean }) {
 
 /**
  * Resolves the dev server URL based on the current platform.
- * - Web: localhost works directly.
- * - iOS Simulator: localhost reaches the host Mac.
+ * - Web and iOS Simulator: localhost reaches the host Mac.
  * - Android Emulator: 10.0.2.2 reaches the host machine.
- * - Real devices: need the dev machine's IP, extracted from Expo's hostUri.
+ * - Real Android devices: need the dev machine's IP, extracted from Expo's hostUri.
  */
 function getServerUrl(): string {
-  if (!__DEV__ || Platform.OS === "web") {
+  if (!__DEV__ || Platform.OS === "web" || Platform.OS === "ios") {
     return "http://localhost:7110";
   }
 
   if (!Device.isDevice) {
-    return Platform.OS === "android" ? "http://10.0.2.2:7110" : "http://localhost:7110";
+    return "http://10.0.2.2:7110";
   }
 
   const hostUri = Constants.expoConfig?.hostUri;

example/expo/README.md

@@ -9,7 +9,7 @@ This app tracks Expo SDK 56.
 ## Prerequisites
 
 - Install dependencies from the repository root with `npm install`.
-- Run an Exceptionless server on `http://localhost:7110`. The example uses localhost for web/iOS Simulator, `10.0.2.2` for Android Emulator, and Expo's `hostUri` for physical devices.
+- Run an Exceptionless server on `http://localhost:7110`. The example uses localhost for web/iOS, `10.0.2.2` for Android Emulator, and Expo's `hostUri` for physical Android devices.
 - Use a development build for native iOS crash reporting.
 
 ## Run
@@ -21,15 +21,15 @@ npm install
 npm run ios --workspace=example/expo
 ```
 
-`npm run ios` runs `expo run:ios`, which prebuilds native files when needed, installs the development build, and starts Metro.
+`npm run ios` runs `expo run:ios`, which prebuilds native files when needed, installs the development build, and starts Metro. The script sets `REACT_NATIVE_PACKAGER_HOSTNAME=localhost` so iOS Simulator stack traces use localhost bundle URLs instead of LAN IPs.
 
 For the checked-in VS Code launch profile and iPad dogfooding, use:
 
 ```bash
 npm run ios:ipad --workspace=example/expo
 ```
 
-`ios:ipad` launches the `iPad Air 11-inch (M3)` simulator on Metro port `8082`, which avoids colliding with another React Native app already using the default `8081` port.
+`ios:ipad` launches the `iPad Air 11-inch (M3)` simulator on Metro port `8082`, which avoids colliding with another React Native app already using the default `8081` port. It also forces the Metro hostname to localhost.
 
 If the development build is already installed, start Metro directly:
 
@@ -58,7 +58,8 @@ The in-app Logs tab should show events being enqueued and sent to the configured
 
 ## Notes
 
-- The example points at `http://localhost:7110` by default and only derives the host IP for physical devices when Expo provides `hostUri`.
+- The example points at `http://localhost:7110` by default and only derives the host IP for Android physical devices when Expo provides `hostUri`.
+- For iOS Simulator stack traces, run Metro with `--localhost` or `REACT_NATIVE_PACKAGER_HOSTNAME=localhost`; otherwise Expo's default LAN mode can put a `10.x.x.x` URL into stack-frame file names.
 - Native iOS crashes are written by the native module and submitted on the next launch.
 - Android currently exercises JavaScript events only; Android native crash reporting is not implemented yet.
 - Generated native folders are intentionally ignored by `example/expo/.gitignore`; run `npm run prebuild --workspace=example/expo` or `npm run ios --workspace=example/expo` to recreate them locally.

example/expo/package.json

@@ -4,11 +4,11 @@
   "version": "3.0.0-dev",
   "main": "./index.js",
   "scripts": {
-    "start": "expo start --dev-client",
-    "start:ios": "expo start --dev-client --ios",
+    "start": "expo start --dev-client --localhost",
+    "start:ios": "expo start --dev-client --ios --localhost",
     "start:web": "expo start --web",
-    "ios": "expo run:ios",
-    "ios:ipad": "expo run:ios --device \"iPad Air 11-inch (M3)\" --port 8082",
+    "ios": "REACT_NATIVE_PACKAGER_HOSTNAME=localhost expo run:ios",
+    "ios:ipad": "REACT_NATIVE_PACKAGER_HOSTNAME=localhost expo run:ios --device \"iPad Air 11-inch (M3)\" --port 8082",
     "web": "expo export --platform web",
     "prebuild": "expo prebuild --clean --no-install",
     "android": "expo run:android"