Run iOS build in CI

.github/workflows/ci.yml

@@ -18,14 +18,11 @@ jobs:
     - name: Clone Flutter SDK
       run: tools/ci/clone-flutter-sdk
 
-    - name: Download Flutter SDK artifacts (flutter precache)
-      run: flutter precache --universal
-
     - name: Download our dependencies (flutter pub get)
       run: flutter pub get
 
     - name: Run tools/check
-      run: TERM=dumb tools/check --no-pub --all --output ci --exclude android
+      run: TERM=dumb tools/check --no-pub --all --output ci --exclude android --exclude ios
 
   android:
     name: "Android build and lint"
@@ -42,11 +39,28 @@ jobs:
     - name: Clone Flutter SDK
       run: tools/ci/clone-flutter-sdk
 
-    - name: Download Flutter SDK artifacts (flutter precache)
-      run: flutter precache --universal
-
     - name: Download our dependencies (flutter pub get)
       run: flutter pub get
 
     - name: Run tools/check
       run: TERM=dumb tools/check --all --output ci android
+
+  ios:
+    name: "iOS build and lint"
+    runs-on: macos-26
+    steps:
+    - uses: actions/checkout@v6
+
+    - name: Install dependencies
+      # Modern Bash and coreutils don't come with macOS; get those.
+      # (See tools/lib/ensure-shell-deps.sh.)
+      run: brew install coreutils bash
+
+    - name: Clone Flutter SDK
+      run: tools/ci/clone-flutter-sdk
+
+    - name: Download our dependencies (flutter pub get)
+      run: flutter pub get
+
+    - name: Run tools/check
+      run: TERM=dumb tools/check --no-pub --all --output ci ios

ios/Flutter/Release.xcconfig

@@ -1,3 +1,7 @@
 #include? "Pods/Target Support Files/Pods-Runner/Pods-Runner.release.xcconfig"
 #include "Generated.xcconfig"
 #include "Zulip.xcconfig"
+
+// Compile Swift with "-warnings-as-errors" but only in release builds, so that
+// it doesn't get in the way of quick local experiments for debugging.
+SWIFT_TREAT_WARNINGS_AS_ERRORS = YES

ios/NotificationService/NotificationService.swift

@@ -65,7 +65,7 @@ class NotificationService: UNNotificationServiceExtension {
         bestAttemptContent.title = improvedNotificationContent.title
         bestAttemptContent.subtitle = improvedNotificationContent.subtitle
         bestAttemptContent.body = improvedNotificationContent.body
-        bestAttemptContent.userInfo = improvedNotificationContent.userInfo as [AnyHashable : Any]
+        bestAttemptContent.userInfo = improvedNotificationContent.userInfo as [AnyHashable: Any]
         contentHandler(bestAttemptContent)
 
       case .failure(let error):  // TODO(log)

ios/Runner/AppDelegate.swift

@@ -18,7 +18,8 @@ import UIKit
 
     let controller = window?.rootViewController as! FlutterViewController
 
-    IosNativeHostApiSetup.setUp(binaryMessenger: controller.binaryMessenger, api: IosNativeHostApiImpl())
+    IosNativeHostApiSetup.setUp(
+      binaryMessenger: controller.binaryMessenger, api: IosNativeHostApiImpl())
 
     // Retrieve the remote notification payload from launch options;
     // this will be null if the launch wasn't triggered by a notification.

tools/check

@@ -34,7 +34,7 @@ default_suites=(
     analyze test
     flutter_version
     build_runner l10n drift pigeon icons
-    android  # This takes multiple minutes in CI, so do it last.
+    android ios  # These take multiple minutes in CI, so do them last.
 )
 
 extra_suites=(
@@ -517,6 +517,78 @@ run_android() {
     flutter build appbundle
 }
 
+run_ios() {
+    # Omitted from this check:
+    #   pubspec.{yaml,lock} tools/check
+    files_check ios/ \
+    || return 0
+
+    # iOS builds require macOS and Xcode.
+    if [ "$(uname -s)" != "Darwin" ]; then
+        echo "Skipping ios suite (not on macOS)."
+        return 0
+    fi
+
+    local build_opts=(
+        ${opt_no_pub:+--no-pub}
+    )
+
+    check_no_uncommitted_or_untracked ios/'*'.swift \
+    || return
+
+    if_verbose echo "Checking for style issues in Swift code..."
+
+    # Generated code (*.g.swift) is omitted from this check.
+    # shellcheck disable=SC2207  # filenames in our own tree, assume well-behaved
+    local swift_targets=(
+        $(git ls-files -- ios/'*'.swift :!:ios/'*'.g.swift)
+    )
+
+    # --in-place enables `tools/check --fix ios`; see `check_no_changes`.
+    # TODO: Once we have a dedicated code formatting check,
+    #       move this swift-format check there.
+    xcrun swift-format format --in-place \
+        --configuration ios/.swift-format \
+        "${swift_targets[@]}" \
+    || return
+
+    check_no_changes "changes to Swift files (swift-format)" ios/'*'.swift \
+    || return
+
+    check_no_uncommitted_or_untracked ios/ macos/ \
+    || return
+
+    if_verbose echo "Checking for automated changes from Flutter tooling..."
+
+    flutter build ios "${build_opts[@]}" --config-only \
+    || return
+
+    # Check macos/ too, because desktop platforms are supported for dev:
+    #   https://github.com/zulip/zulip-flutter#desktop-support
+    # (This could live in its own suite. If doing that, we'd probably
+    # still want to run it in the same GitHub CI workflow as the iOS build,
+    # since GitHub's macOS-based runners use a lot of our free quota:
+    #   https://github.com/zulip/zulip-flutter/issues/329#issue-1950704934
+    # .)
+    flutter build macos "${build_opts[@]}" --config-only \
+    || return
+
+    check_no_changes "changes to ios" ios/ \
+    || return
+
+    check_no_changes "changes to macos" macos/ \
+    || return
+
+    if_verbose echo "Building for iOS (in release mode)..."
+
+    # Skip codesigning in CI.
+    if [ "${opt_output}" = ci ]; then
+        build_opts+=( --no-codesign )
+    fi
+
+    flutter build ipa "${build_opts[@]}"
+}
+
 run_shellcheck() {
     # Omitted from this check: nothing (nothing known, anyway).
     files_check tools/ '!*.'{dart,js,json} \
@@ -568,7 +640,9 @@ print_header() {
 
     # We avoid `flutter --version` because, weirdly, when run in a
     # GitHub Actions step it takes about 30 seconds.  (The first time;
-    # it's fast subsequent times.)  That's even after `flutter precache`.
+    # it's fast subsequent times.)  That's even when the Flutter tool's
+    # binary artifacts have already been downloaded (which, in CI,
+    # happens during the `flutter pub get` step).
     describe_git_head "flutter/flutter" "$(flutter_tree)"
 
     dart --version
@@ -590,6 +664,7 @@ for suite in "${opt_suites[@]}"; do
         pigeon)       maybe_time "$suite" run_pigeon ;;
         icons)        maybe_time "$suite" run_icons ;;
         android)      maybe_time "$suite" run_android ;;
+        ios)          maybe_time "$suite" run_ios ;;
         shellcheck)   maybe_time "$suite" run_shellcheck ;;
         *)            echo >&2 "Internal error: unknown suite $suite" ;;
     esac || failed+=( "$suite" )