ci: prepare ios simulator before running

Author: russellwheatley

.github/workflows/scripts/prepare-ios-simulator.sh

@@ -0,0 +1,60 @@
+#!/usr/bin/env bash
+
+set -euo pipefail
+
+if [[ -z "${IOS_SIMULATOR_DEVICE:-}" ]]; then
+  echo "IOS_SIMULATOR_DEVICE must be set."
+  exit 1
+fi
+
+echo "--- Available simulators (diagnostic) ---"
+xcrun simctl list
+
+SIMULATOR_UDID="$(python3 - <<'PY'
+import json
+import os
+import re
+import subprocess
+import sys
+
+target_name = os.environ["IOS_SIMULATOR_DEVICE"]
+raw = subprocess.check_output(
+    ["xcrun", "simctl", "list", "devices", "available", "-j"],
+    text=True,
+)
+devices_by_runtime = json.loads(raw)["devices"]
+pattern = re.compile(r"com\.apple\.CoreSimulator\.SimRuntime\.iOS-(\d+)(?:-(\d+))?")
+
+candidates = []
+for runtime_key, devices in devices_by_runtime.items():
+    match = pattern.fullmatch(runtime_key)
+    if not match:
+        continue
+
+    version = (int(match.group(1)), int(match.group(2) or 0))
+    for device in devices:
+        if device.get("isAvailable") and device.get("name") == target_name:
+            candidates.append((version, device["udid"]))
+
+if not candidates:
+    sys.exit(f"No available simulator found for {target_name} in installed iOS runtimes.")
+
+candidates.sort(reverse=True)
+print(candidates[0][1])
+PY
+)"
+
+if [[ -n "${GITHUB_OUTPUT:-}" ]]; then
+  echo "udid=$SIMULATOR_UDID" >> "$GITHUB_OUTPUT"
+else
+  echo "Resolved simulator UDID: $SIMULATOR_UDID"
+fi
+
+if ! boot_output="$(xcrun simctl boot "$SIMULATOR_UDID" 2>&1)"; then
+  if [[ "$boot_output" != *"Unable to boot device in current state: Booted"* ]]; then
+    echo "$boot_output"
+    exit 1
+  fi
+fi
+
+xcrun simctl bootstatus "$SIMULATOR_UDID" -b

.github/workflows/swiftui-auth.yml

@@ -23,6 +23,10 @@ on:
 permissions:
   contents: read
 
+env:
+  XCODE_VERSION: latest-stable
+  IOS_SIMULATOR_DEVICE: iPhone 17 Pro
+
 jobs:
   format-check:
     name: Swift Format Check
@@ -37,7 +41,7 @@ jobs:
       - name: Check Swift formatting
         run: bash lint-swift.sh
 
-  # Package Unit Tests (standalone, no emulator needed)
+  # Package Unit Tests (simulator-backed)
   unit-tests:
     name: Package Unit Tests
     runs-on: macos-26
@@ -48,22 +52,20 @@ jobs:
       - name: Install xcpretty
         run: gem install xcpretty
 
-      - uses: maxim-lobanov/setup-xcode@v1
+      - uses: maxim-lobanov/setup-xcode@9a237eadec58c1a4e3c19e27a1f6e2a3dce0a919
         with:
-          xcode-version: latest-stable
-      - name: Workaround Simulator Availability issues
-        run: |
-          # Just listing the installed simulators fixes availability inconsistency
-          # Without this, runs fail *intermittently* with build target not available because simulators not available
-          # See https://github.com/actions/runner-images/issues/13459#issuecomment-3681674842
-          xcrun simctl list
+          xcode-version: ${{ env.XCODE_VERSION }}
+
+      - name: Prepare iOS Simulator
+        id: prepare-simulator
+        run: ./.github/workflows/scripts/prepare-ios-simulator.sh
 
       - name: Run FirebaseSwiftUI Package Unit Tests
         run: |
           set -o pipefail
           xcodebuild test \
             -scheme FirebaseUI-Package \
-            -destination 'platform=iOS Simulator,OS=26.4,name=iPhone 17 Pro' \
+            -destination "id=${{ steps.prepare-simulator.outputs.udid }}" \
             -enableCodeCoverage YES \
             -resultBundlePath FirebaseSwiftUIPackageTests.xcresult | tee FirebaseSwiftUIPackageTests.log | xcpretty --test --color --simple
             
@@ -111,24 +113,21 @@ jobs:
       - name: Install xcpretty
         run: gem install xcpretty
 
-      - uses: maxim-lobanov/setup-xcode@v1
+      - uses: maxim-lobanov/setup-xcode@9a237eadec58c1a4e3c19e27a1f6e2a3dce0a919
         with:
-          xcode-version: latest-stable
+          xcode-version: ${{ env.XCODE_VERSION }}
 
-      - name: Workaround Simulator Availability issues
-        run: |
-          # Just listing the installed simulators fixes availability inconsistency
-          # Without this, runs fail *intermittently* with build target not available because simulators not available
-          # See https://github.com/actions/runner-images/issues/13459#issuecomment-3681674842
-          xcrun simctl list
+      - name: Prepare iOS Simulator
+        id: prepare-simulator
+        run: ./.github/workflows/scripts/prepare-ios-simulator.sh
 
       - name: Build for Integration Tests
         run: |
           cd ./e2eTest/FirebaseSwiftUIExample
           set -o pipefail
           xcodebuild build-for-testing \
             -scheme FirebaseSwiftUIExampleTests \
-            -destination 'platform=iOS Simulator,OS=26.4,name=iPhone 17 Pro' \
+            -destination "id=${{ steps.prepare-simulator.outputs.udid }}" \
             -enableCodeCoverage YES | xcpretty --color --simple
             
       - name: Run Integration Tests
@@ -137,7 +136,8 @@ jobs:
           set -o pipefail
           xcodebuild test-without-building \
             -scheme FirebaseSwiftUIExampleTests \
-            -destination 'platform=iOS Simulator,OS=26.4,name=iPhone 17 Pro' \
+            -destination "id=${{ steps.prepare-simulator.outputs.udid }}" \
+            -parallel-testing-enabled NO \
             -enableCodeCoverage YES \
             -resultBundlePath FirebaseSwiftUIExampleTests.xcresult | tee FirebaseSwiftUIExampleTests.log | xcpretty --test --color --simple
             
@@ -185,24 +185,21 @@ jobs:
       - name: Install xcpretty
         run: gem install xcpretty
 
-      - uses: maxim-lobanov/setup-xcode@v1
+      - uses: maxim-lobanov/setup-xcode@9a237eadec58c1a4e3c19e27a1f6e2a3dce0a919
         with:
-          xcode-version: latest-stable
+          xcode-version: ${{ env.XCODE_VERSION }}
 
-      - name: Workaround Simulator Availability issues
-        run: |
-          # Just listing the installed simulators fixes availability inconsistency
-          # Without this, runs fail *intermittently* with build target not available because simulators not available
-          # See https://github.com/actions/runner-images/issues/13459#issuecomment-3681674842
-          xcrun simctl list
+      - name: Prepare iOS Simulator
+        id: prepare-simulator
+        run: ./.github/workflows/scripts/prepare-ios-simulator.sh
 
       - name: Build for UI Tests
         run: |
           cd ./e2eTest/FirebaseSwiftUIExample
           set -o pipefail
           xcodebuild build-for-testing \
             -scheme FirebaseSwiftUIExampleUITests \
-            -destination 'platform=iOS Simulator,OS=26.4,name=iPhone 17 Pro' \
+            -destination "id=${{ steps.prepare-simulator.outputs.udid }}" \
             -enableCodeCoverage YES | xcpretty --color --simple
             
       - name: Run UI Tests
@@ -211,7 +208,7 @@ jobs:
           set -o pipefail
           xcodebuild test-without-building \
             -scheme FirebaseSwiftUIExampleUITests \
-            -destination 'platform=iOS Simulator,OS=26.4,name=iPhone 17 Pro' \
+            -destination "id=${{ steps.prepare-simulator.outputs.udid }}" \
             -parallel-testing-enabled NO \
             -enableCodeCoverage YES \
             -resultBundlePath FirebaseSwiftUIExampleUITests.xcresult | tee FirebaseSwiftUIExampleUITests.log | xcpretty --test --color --simple