fix(rn): improve Metro error detection and use Debug builds for iOS

Two fixes:

1. Enhanced app verification to detect Metro connection errors:
   - Check for "unable to load script" and Metro connection failures
   - These appear in red box but not as "fatal" in logcat
   - Increased logcat tail from 50 to 100 lines
   - Separate checks for Metro errors vs fatal errors

2. Use Debug builds for iOS E2E tests:
   - Release builds use pre-bundled JS (don't connect to Metro)
   - Debug builds connect to Metro on RCT_METRO_PORT
   - Set IOS_BUILD_CONFIG=Debug in test suites

This ensures tests fail when Metro connection is broken.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: abueide

examples/react-native/tests/test-suite-all-e2e.yaml

@@ -172,7 +172,7 @@ processes:
     command: |
       set -e
 
-      BUILD_CONFIG="${IOS_BUILD_CONFIG:-Release}"
+      BUILD_CONFIG="${IOS_BUILD_CONFIG:-Debug}"
       echo "Building React Native app (${BUILD_CONFIG})"
 
       # Source Metro environment so React Native uses correct port
@@ -201,18 +201,48 @@ processes:
   verify-android-running:
     command: |
       echo "Waiting for Android app to start..."
+
+      # Resolve emulator serial for log checking
+      serial=""
+      state_dir="${ANDROID_RUNTIME_DIR:-.devbox/virtenv}/${SUITE_NAME:-default}"
+      if [ -f "$state_dir/emulator-serial.txt" ]; then
+        serial="$(cat "$state_dir/emulator-serial.txt")"
+      fi
+      if [ -z "$serial" ]; then
+        serial="emulator-${EMU_PORT:-5554}"
+      fi
+
       max_attempts=15
       attempt=0
       while [ $attempt -lt $max_attempts ]; do
-        if android.sh app status; then
-          echo "✓ Android app is running"
-          mkdir -p reports
-          touch reports/.e2e-android-passed
-          exit 0
+        if ! android.sh app status; then
+          attempt=$((attempt + 1))
+          echo "  Attempt $attempt/$max_attempts: App not running yet..."
+          sleep 2
+          continue
         fi
-        attempt=$((attempt + 1))
-        echo "  Attempt $attempt/$max_attempts: App not running yet..."
-        sleep 2
+
+        echo "  App process is running, checking logs for errors..."
+
+        # Check logcat for Metro connection errors
+        log_output=$(adb -s "$serial" logcat -d -s ReactNativeJS:* ReactNative:* -t 100 2>/dev/null || true)
+
+        if echo "$log_output" | grep -qi "unable.*load.*script\|could.*not.*connect.*metro\|connection.*refused.*8081"; then
+          echo "ERROR: App cannot connect to Metro bundler:" >&2
+          echo "$log_output" | grep -iE "unable|load|script|connect|metro|refused|8081" | tail -20 >&2
+          exit 1
+        fi
+
+        if echo "$log_output" | grep -qi "fatal.*error\|exception.*error"; then
+          echo "ERROR: App encountered fatal errors:" >&2
+          echo "$log_output" | grep -iE "fatal|exception" | tail -15 >&2
+          exit 1
+        fi
+
+        echo "✓ Android app is running and connected to Metro"
+        mkdir -p reports
+        touch reports/.e2e-android-passed
+        exit 0
       done
 
       echo "ERROR: Android app did not start within timeout" >&2

examples/react-native/tests/test-suite-android-e2e.yaml

@@ -149,16 +149,25 @@ processes:
 
         echo "  App process is running, checking logs for errors..."
 
-        # Check logcat for fatal errors
-        log_output=$(adb -s "$serial" logcat -d -s ReactNativeJS:* ReactNative:* -t 50 2>/dev/null || true)
-        if echo "$log_output" | grep -qi "fatal.*error\|exception.*error\|unable.*load.*script\|could.*not.*connect.*metro"; then
-          echo "ERROR: App encountered errors:" >&2
-          echo "$log_output" | grep -iE "fatal|exception|error|failed|unable|could not" | tail -15 >&2
+        # Check logcat for errors (including Metro connection issues)
+        log_output=$(adb -s "$serial" logcat -d -s ReactNativeJS:* ReactNative:* -t 100 2>/dev/null || true)
+
+        # Check for Metro connection errors (these appear in red box but may not be "fatal")
+        if echo "$log_output" | grep -qi "unable.*load.*script\|could.*not.*connect.*metro\|connection.*refused.*8081"; then
+          echo "ERROR: App cannot connect to Metro bundler:" >&2
+          echo "$log_output" | grep -iE "unable|load|script|connect|metro|refused|8081" | tail -20 >&2
+          exit 1
+        fi
+
+        # Check for other fatal errors
+        if echo "$log_output" | grep -qi "fatal.*error\|exception.*error"; then
+          echo "ERROR: App encountered fatal errors:" >&2
+          echo "$log_output" | grep -iE "fatal|exception" | tail -15 >&2
           exit 1
         fi
 
-        # Success: app is running and no fatal errors
-        echo "✓ App is running (no fatal errors detected)"
+        # Success: app is running and no errors
+        echo "✓ App is running and connected to Metro"
         mkdir -p reports
         touch reports/.e2e-passed
         exit 0

examples/react-native/tests/test-suite-ios-e2e.yaml

@@ -3,6 +3,7 @@ version: "0.5"
 environment:
   - "IOS_DEVICE=${IOS_DEFAULT_DEVICE:-max}"
   - "SUITE_NAME=rn-ios-e2e"
+  - "IOS_BUILD_CONFIG=Debug"
   - "ANDROID_SKIP_SETUP=1"
   - "TEST_TUI=${TEST_TUI:-false}"
   - "REACT_NATIVE_VIRTENV=${REACT_NATIVE_VIRTENV}"