Added revamped workflow that now tests this library against both the …

…current and N-1 version of Flutter.

.github/workflows/ci.yml

@@ -1,5 +1,10 @@
 name: CI
 
+env:
+  # Note: The version below should be manually updated to the latest second most recent version
+  # after a new stable version comes out.
+  flutter_n_minus_one_version: "3.24.5"
+
 on:
   pull_request:
     paths-ignore:
@@ -9,48 +14,50 @@ on:
       - master
     paths-ignore:
       - '**.md'
-  workflow_dispatch:
+
+concurrency:
+  group: ${{ github.workflow }}-${{ github.ref }}
+  cancel-in-progress: true
 
 jobs:
-  check-format:
-      name: Check format using dart format.
-      runs-on: ubuntu-latest
-
-      steps:
-        - name: Checkout code
-          uses: actions/checkout@v4
-        - name: Flutter Action
-          uses: subosito/flutter-action@v2
-        - name: Check format
-          run: dart format . --set-exit-if-changed
-
-  lint:
-    name: Lint
+  # Does a sanity check that packages at least pass analysis on the N-1
+  # versions of Flutter stable if the package claims to support that version.
+  # This is to minimize accidentally making changes that break old versions
+  # (which we don't commit to supporting, but don't want to actively break)
+  # without updating the constraints.
+  lint_and_build:
+    strategy:
+      matrix:
+        flutter-version:
+          # The version of Flutter to use should use the minimum Dart SDK version supported by the package,
+          # refer to https://docs.flutter.dev/development/tools/sdk/releases.
+          - ${{ env.flutter_n_minus_one_version }}
+          - "3.x"
+    name: Checks formatting, lints, and tests this library against a specific Flutter version.
     runs-on: ubuntu-latest
-
     steps:
-      - name: Checkout code
+      - name: 📚 Git Checkout
         uses: actions/checkout@v4
-      - name: Flutter Action
+
+      - name: 🐦 Setup Flutter
         uses: subosito/flutter-action@v2
-      - name: Install Package Dependencies
+        with:
+          flutter-version: ${{matrix.flutter-version}}
+          channel: stable
+          cache: true
+          cache-key: flutter-:os:-:channel:-:version:-:arch:-:hash:-${{ hashFiles('**/pubspec.lock') }}
+
+      - name: 📦 Install Dependencies
         run: flutter packages get
-      - name: Get dependencies for example
-        run: flutter pub get
-        working-directory: example
-      - name: Lint using flutter analyze
-        run: flutter analyze .
-
-  test:
-    name: Run tests.
-    runs-on: ubuntu-latest
 
-    steps:
-      - name: Checkout code
-        uses: actions/checkout@v4
-      - name: Flutter Action
-        uses: subosito/flutter-action@v2
-      - name: Run flutter test
-        run: |
-          flutter pub get
-          flutter test
+      - name: ✨ Check Formatting
+        run: dart format --set-exit-if-changed lib
+
+      - name: 🕵️ Analyze
+        run: flutter analyze lib
+
+      - name: 🧪 Run Tests
+        run: flutter test --no-pub --coverage --test-randomize-ordering-seed random
+
+      - name: 📁 Upload coverage to Codecov
+        uses: codecov/codecov-action@v5