diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index e01fec0..f1fd21e 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -1,25 +1,63 @@
-name: ci
+name: Dart CI
 
 on:
   push:
     branches: [ master ]
   pull_request:
+    branches: [ master ]
   schedule:
-    # “At 00:00 (UTC) on Sunday.”
-    - cron: '0 0 * * 0'
+    - cron: "0 0 * * 0"
+
+env:
+  PUB_ENVIRONMENT: bot.github
 
 jobs:
-  ci:
+  # Check code formatting and static analysis on a single OS (linux)
+  # against Dart dev.
+  analyze:
     runs-on: ubuntu-latest
+    strategy:
+      fail-fast: false
+      matrix:
+        sdk: [dev]
     steps:
-    - uses: cedx/setup-dart@v2
-      with:
-        release-channel: dev
-    - run: dart --version
-    - uses: actions/checkout@v2
+      - uses: actions/checkout@v2
+      - uses: dart-lang/setup-dart@v1.0
+        with:
+          sdk: ${{ matrix.sdk }}
+      - id: install
+        name: Install dependencies
+        run: dart pub get
+      - name: Check formatting
+        run: dart format --output=none --set-exit-if-changed .
+        if: always() && steps.install.outcome == 'success'
+      - name: Analyze code
+        run: dart analyze --fatal-infos
+        if: always() && steps.install.outcome == 'success'
 
-    - run: pub get
-
-    - run: dart format --output=none --set-exit-if-changed .
-    - run: dart analyze --fatal-infos .
-    - run: pub run test -p vm,chrome
+  # Run tests on a matrix consisting of two dimensions:
+  # 1. OS: ubuntu-latest, (macos-latest, windows-latest)
+  # 2. release channel: dev
+  test:
+    needs: analyze
+    runs-on: ${{ matrix.os }}
+    strategy:
+      fail-fast: false
+      matrix:
+        # Add macos-latest and/or windows-latest if relevant for this package.
+        os: [ubuntu-latest]
+        sdk: [2.12.0, dev]
+    steps:
+      - uses: actions/checkout@v2
+      - uses: dart-lang/setup-dart@v1.0
+        with:
+          sdk: ${{ matrix.sdk }}
+      - id: install
+        name: Install dependencies
+        run: dart pub get
+      - name: Run VM tests
+        run: dart test --platform vm --test-randomize-ordering-seed=random
+        if: always() && steps.install.outcome == 'success'
+      - name: Run Chrome tests
+        run: dart test --platform chrome --test-randomize-ordering-seed=random
+        if: always() && steps.install.outcome == 'success'
diff --git a/CHANGELOG.md b/CHANGELOG.md
index f8fe237..e39b9d2 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,3 +1,5 @@
+## 1.15.1-dev
+
 ## 1.15.0
 
 * Stable release for null safety.
diff --git a/lib/src/iterable_extensions.dart b/lib/src/iterable_extensions.dart
index 82217e9..cddc497 100644
--- a/lib/src/iterable_extensions.dart
+++ b/lib/src/iterable_extensions.dart
@@ -192,10 +192,10 @@
 
   /// Expands each element and index to a number of elements in a new iterable.
   Iterable<R> expandIndexed<R>(
-      Iterable<R> Function(int index, T element) expend) sync* {
+      Iterable<R> Function(int index, T element) expand) sync* {
     var index = 0;
     for (var element in this) {
-      yield* expend(index++, element);
+      yield* expand(index++, element);
     }
   }
 
diff --git a/pubspec.yaml b/pubspec.yaml
index 03a3f54..9ce3549 100644
--- a/pubspec.yaml
+++ b/pubspec.yaml
@@ -1,11 +1,11 @@
 name: collection
-version: 1.15.0
+version: 1.15.1-dev
 
 description: Collections and utilities functions and classes related to collections.
-homepage: https://github.com/dart-lang/collection
+repository: https://github.com/dart-lang/collection
 
 environment:
-  sdk: ">=2.12.0-0 <3.0.0"
+  sdk: ">=2.12.0 <3.0.0"
 
 dev_dependencies:
   pedantic: ^1.10.0-nullsafety