From a156874532fd9be3489618112327b8441baec5ba Mon Sep 17 00:00:00 2001
From: Ngo Quoc Dat <datlechin@gmail.com>
Date: Mon, 19 Oct 2026 03:35:27 +0700
Subject: [PATCH] ci(ios): boot the simulator while the app builds

---
 .claude/rules/ci.md             |  5 ++--
 .github/workflows/ios-tests.yml | 41 +++++++++++++++++++++++++--------
 2 files changed, 34 insertions(+), 12 deletions(-)

diff --git a/.claude/rules/ci.md b/.claude/rules/ci.md
index 9b2f3c0190..dedff7e14f 100644
--- a/.claude/rules/ci.md
+++ b/.claude/rules/ci.md
@@ -52,8 +52,9 @@ The required check names are in `AGENTS.md` (CI). Reading a red check: `.claude/
 ## iOS and Package Tests (`ios-tests.yml`)
 
 - Triggers and concurrency as macOS Tests. `Changes (iOS)` outputs `run` (detector `ios`) and `oracle` (detector `oracle`).
-- 50 minutes on `xcode-27`, simulator `iPhone 18 Pro`. The iOS platform is downloaded only when that simulator is missing.
-- `TableProMobileTests` runs with `-parallel-testing-enabled NO`: a second booted simulator killed runs with "(ipc/mig) server died" on the 3-core runner. `TableProMobile/project.yml` says `parallelizable: true`, which every run overrides.
+- 50 minutes on `xcode-27`, simulator `iPhone 18 Pro` on the newest iOS runtime that has it. The iOS platform is downloaded only when that simulator is missing.
+- Right after setup-xcode the job boots that simulator by UDID, so its first boot overlaps the build. `xcodebuild test` names it with `-destination id=`.
+- `TableProMobileTests` runs with `-parallel-testing-enabled NO` on that one simulator: a second booted simulator killed runs with "(ipc/mig) server died" on the 3-core runner. `TableProMobile/project.yml` says `parallelizable: true`, which every run overrides.
 - `swift test --package-path Packages/TableProCore --parallel`, then TableProOracle with `--force-resolved-versions` when its detector is not false. Each step has `if: !cancelled()`, so one red step never hides the next.
 - The summary step always runs. Evidence uploads only on failure.
 
diff --git a/.github/workflows/ios-tests.yml b/.github/workflows/ios-tests.yml
index 6ccbf1f1ef..15bc6f9b99 100644
--- a/.github/workflows/ios-tests.yml
+++ b/.github/workflows/ios-tests.yml
@@ -46,12 +46,38 @@ jobs:
     runs-on: xcode-27
     timeout-minutes: 50
     env:
-      DESTINATION: platform=iOS Simulator,name=iPhone 18 Pro
+      SIMULATOR: iPhone 18 Pro
     steps:
       - uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7.0.1
 
       - uses: ./.github/actions/setup-xcode
 
+      # Booted ahead of the build so the first boot overlaps the compile instead of following it.
+      # The image ships the iOS 27.0 runtime; downloading the one for Xcode's newer SDK costs minutes.
+      # A destination by name takes the newest runtime, so the lookup does too.
+      - name: Boot the simulator
+        id: simulator
+        run: |
+          set -euo pipefail
+          find_simulator() {
+            xcrun simctl list devices available -j | jq -r --arg name "$SIMULATOR" '
+              [.devices | to_entries[] | select(.key | test("\\.iOS-[0-9-]+$"))
+                | {version: (.key | capture("iOS-(?<v>[0-9-]+)$").v | split("-") | map(tonumber)),
+                   udid: (.value[] | select(.name == $name) | .udid)}]
+              | sort_by(.version) | last | .udid // empty'
+          }
+          udid="$(find_simulator)"
+          if [ -z "$udid" ]; then
+            sudo xcodebuild -downloadPlatform iOS
+            udid="$(find_simulator)"
+          fi
+          if [ -z "$udid" ]; then
+            echo "No $SIMULATOR simulator, even after downloading the iOS platform." >&2
+            exit 1
+          fi
+          xcrun simctl boot "$udid"
+          echo "udid=$udid" >> "$GITHUB_OUTPUT"
+
       - uses: ./.github/actions/setup-xcodegen
 
       - name: Download static libraries
@@ -62,24 +88,19 @@ jobs:
       - name: Generate the Xcode project
         run: scripts/generate-project.sh ios
 
-      # The image ships the iOS 27.0 runtime. Downloading the one for Xcode's newer SDK costs minutes.
-      - name: Make sure the simulator exists
-        run: |
-          if ! xcrun simctl list devices available | grep -F "iPhone 18 Pro (" > /dev/null; then
-            sudo xcodebuild -downloadPlatform iOS
-          fi
-
       # One simulator, not clones: on a 3-core runner a second booted simulator killed runs with
       # "(ipc/mig) server died", and TableProMobileTests is one bundle that never split anyway.
       - name: Run the iOS tests
+        env:
+          SIMULATOR_UDID: ${{ steps.simulator.outputs.udid }}
         run: |
           set -o pipefail
           xcodebuild test \
             -project TableProMobile/TableProMobile.xcodeproj -scheme TableProMobile \
-            -destination "$DESTINATION" -only-testing:TableProMobileTests \
+            -destination "platform=iOS Simulator,id=$SIMULATOR_UDID" -only-testing:TableProMobileTests \
             -parallel-testing-enabled NO \
             -skipPackagePluginValidation -resultBundlePath iOS.xcresult \
-            CODE_SIGNING_ALLOWED=NO COMPILER_INDEX_STORE_ENABLE=NO \
+            CODE_SIGNING_ALLOWED=NO COMPILER_INDEX_STORE_ENABLE=NO COMPILATION_CACHE_ENABLE_CACHING=NO \
             | xcbeautify --renderer github-actions
 
       # --parallel is what makes swift test write the XCTest xunit file. Without it only the Swift