ci: only build native apps a PR changes

.github/workflows/ci.yml

@@ -1,3 +1,23 @@
+# CI for every app under apps/.
+#
+# Don't list apps in this file. The `changes` job reads apps/ and picks which
+# apps to run:
+#   - PR touching only apps/<name>/ -> just those apps
+#   - PR touching anything else (lockfile, packages/, this file, root config)
+#     -> every app
+#   - PR touching only docs (docs/, *.md, images) -> nothing
+#   - push to main -> every app
+#
+# `check` (typecheck, lint, test, JS bundle), `android` and `ios` all run for
+# that list. A new app is picked up automatically, as long as:
+#   - apps/<name>/package.json is named @offline-app-examples/<name>
+#   - apps/<name>/ios has exactly one <Scheme>.xcworkspace whose scheme has
+#     the same name
+#
+# Branch protection should only require `check` and `native`, never per-app
+# job names like `android (cowrite)`. Those only exist on PRs that touch that
+# app. `native` rolls up all the android/ios jobs into one result.
+
 name: CI
 
 on:
@@ -16,9 +36,44 @@ env:
   TURBO_TELEMETRY_DISABLED: 1
 
 jobs:
+  changes:
+    runs-on: ubuntu-latest
+    outputs:
+      apps: ${{ steps.apps.outputs.apps }}
+      filter: ${{ steps.apps.outputs.filter }}
+    steps:
+      - uses: actions/checkout@v7
+        with:
+          # The PR merge commit plus its parents, so HEAD^1..HEAD is the PR's diff.
+          fetch-depth: 2
+      - id: apps
+        run: |
+          all=$(ls apps | jq -Rsc 'split("\n") | map(select(length > 0))')
+          apps=$all
+          if [ "${{ github.event_name }}" = pull_request ]; then
+            files=$(git diff --name-only HEAD^1 HEAD | grep -vE '^docs/|\.(md|gif|png|jpe?g)$' || true)
+            if [ -z "$files" ]; then
+              apps='[]'
+            elif ! grep -qv '^apps/' <<<"$files"; then
+              apps=$(grep '^apps/' <<<"$files" | cut -d/ -f2 \
+                | jq -Rsc --argjson all "$all" 'split("\n") | unique | map(select(IN($all[])))')
+            fi
+          fi
+          echo "apps=$apps" | tee -a "$GITHUB_OUTPUT"
+          # No turbo filter when every app runs, so packages/ is checked too.
+          if [ "$apps" != "$all" ]; then
+            filter=$(jq -r 'map("--filter=@offline-app-examples/" + .) | join(" ")' <<<"$apps")
+          fi
+          echo "filter=${filter:-}" | tee -a "$GITHUB_OUTPUT"
+
   check:
+    needs: changes
+    if: needs.changes.outputs.apps != '[]'
     runs-on: ubuntu-latest
     timeout-minutes: 20
+    env:
+      APPS: ${{ needs.changes.outputs.apps }}
+      FILTER: ${{ needs.changes.outputs.filter }}
     steps:
       - uses: actions/checkout@v7
       - uses: pnpm/action-setup@v6
@@ -27,29 +82,30 @@ jobs:
           node-version: 24
           cache: pnpm
       - run: pnpm install --frozen-lockfile
-      - run: pnpm typecheck
-      - run: pnpm lint
-      - run: pnpm test
+      - run: pnpm exec turbo typecheck $FILTER
+      - run: pnpm exec turbo lint $FILTER
+      - run: pnpm exec turbo test $FILTER
       - name: Bundle JavaScript for iOS and Android
         run: |
-          for app in apps/*/; do
+          for app in $(jq -r '.[]' <<<"$APPS"); do
             for platform in ios android; do
               echo "::group::$app $platform"
-              (cd "$app" && npx react-native bundle --platform "$platform" --dev false \
-                --entry-file index.js --bundle-output "$RUNNER_TEMP/$(basename "$app").$platform.jsbundle" \
-                --assets-dest "$RUNNER_TEMP/assets-$(basename "$app")-$platform")
+              (cd "apps/$app" && npx react-native bundle --platform "$platform" --dev false \
+                --entry-file index.js --bundle-output "$RUNNER_TEMP/$app.$platform.jsbundle" \
+                --assets-dest "$RUNNER_TEMP/assets-$app-$platform")
               echo "::endgroup::"
             done
           done
 
   android:
-    needs: check
+    needs: [check, changes]
+    if: needs.changes.outputs.apps != '[]'
     runs-on: ubuntu-latest
     timeout-minutes: 45
     strategy:
       fail-fast: false
       matrix:
-        app: [tictactogether, stocksync, orderup, cowrite, outagenet, yardgate, eventfloor, agrimesh, chargecatch, surfrroll, dockhand]
+        app: ${{ fromJSON(needs.changes.outputs.apps) }}
     steps:
       - uses: actions/checkout@v7
       - uses: pnpm/action-setup@v6
@@ -88,35 +144,14 @@ jobs:
           exit 1
 
   ios:
-    needs: check
+    needs: [check, changes]
+    if: needs.changes.outputs.apps != '[]'
     runs-on: macos-15
     timeout-minutes: 60
     strategy:
       fail-fast: false
       matrix:
-        include:
-          - app: tictactogether
-            scheme: Tictactogether
-          - app: stocksync
-            scheme: StockSync
-          - app: orderup
-            scheme: OrderUp
-          - app: cowrite
-            scheme: Cowrite
-          - app: outagenet
-            scheme: OutageNet
-          - app: yardgate
-            scheme: YardGate
-          - app: eventfloor
-            scheme: EventFloor
-          - app: agrimesh
-            scheme: AgriMesh
-          - app: chargecatch
-            scheme: ChargeCatch
-          - app: surfrroll
-            scheme: SurfrRoll
-          - app: dockhand
-            scheme: DockHand
+        app: ${{ fromJSON(needs.changes.outputs.apps) }}
     steps:
       - uses: actions/checkout@v7
       - uses: pnpm/action-setup@v6
@@ -153,6 +188,17 @@ jobs:
       - name: Build for the iOS simulator
         working-directory: apps/${{ matrix.app }}/ios
         run: |
-          xcodebuild -workspace "${{ matrix.scheme }}.xcworkspace" -scheme "${{ matrix.scheme }}" \
+          scheme=$(basename *.xcworkspace .xcworkspace)
+          xcodebuild -workspace "$scheme.xcworkspace" -scheme "$scheme" \
             -configuration Debug -sdk iphonesimulator -destination 'generic/platform=iOS Simulator' \
             -derivedDataPath "$RUNNER_TEMP/dd" CODE_SIGNING_ALLOWED=NO -quiet build
+
+  # Single required check for the native builds, since the matrix varies per PR.
+  native:
+    if: always()
+    needs: [check, changes, android, ios]
+    runs-on: ubuntu-latest
+    steps:
+      - if: contains(needs.*.result, 'failure') || contains(needs.*.result, 'cancelled')
+        run: exit 1
+      - run: echo "native builds passed or were not needed"

docs/DEMO_APPS_PLAN.md

@@ -74,7 +74,7 @@ Planning only — no app scaffolds until implementation starts.
 | **A — Staff ops** | Event organiser | MLS staff group + OfflineID; dispatch over crowd relay (relay cannot read) |
 | **B — Gate sync** | Ticketing / gate POS | Shared **admission ledger** across scanners; idempotent mock platform ingest |
 
-**Catalogue bar (Satvik / Mizan parity):** End-to-end RN app, seeded reset, README scripts, **`demo-staff.gif`** + **`demo-gate.gif`**, root README embeds, CI matrix row.
+**Catalogue bar (Satvik / Mizan parity):** End-to-end RN app, seeded reset, README scripts, **`demo-staff.gif`** + **`demo-gate.gif`**, root README embeds (CI picks up new apps automatically; see the top of `.github/workflows/ci.yml`).
 
 **Flow A (short):** Security sends “Medic, Section B”; staff receiver gets it on **Bluetooth mesh** when cell is saturated; optional third phone relays.