Test Python 3.12 and limit windows and macos CI runtime. (#205)

* Test Python 3.12.

Also limit the number of jobs that run on limited macOS and windows runners.

* Fix job name.

* Remove redundant minimal dependency test.

Minimal was identical to newest.

* Add pip cache to reduce run time.

* Also test macos and windows on oldest.

* Fix job name.

---------

Co-authored-by: Corwin Kerr <[email protected]>

.github/workflows/run-pytest.yml

@@ -16,41 +16,62 @@ concurrency:
   cancel-in-progress: true
 jobs:
   test:
+    name: test (${{ matrix.os }}, ${{ matrix.python }}, ${{ matrix.dependencies }})
     runs-on: ${{ matrix.os }}
     strategy:
       fail-fast: false
       matrix:
-        os: [ubuntu-latest, windows-latest, macos-latest]
-        config: [ {python: '3.8', dependencies: 'newest'},
-                  {python: '3.9', dependencies: 'newest'},
-                  {python: '3.10', dependencies: 'newest'},
-                  {python: '3.11', dependencies: 'newest'},
-                  {python: '3.11', dependencies: 'minimal'},
-                  {python: '3.8', dependencies: 'oldest'} ]
+        os: [ubuntu-latest]
+        python: ['3.8', '3.9', '3.10', '3.11', '3.12']
+        include:
+          # Default to newest dependencies
+          - dependencies: 'newest'
+          # Test the oldest Python with the oldest supported dependencies.
+          - python: '3.8'
+            dependencies: 'oldest'
+          # Test macOS and windows on oldest and latest versions.
+          - os: 'macos-latest'
+            python: '3.12'
+            dependencies: 'newest'
+          - os: 'windows-latest'
+            python: '3.12'
+            dependencies: 'newest'
+          - os: 'windows-latest'
+            python: '3.8'
+            dependencies: 'oldest'
+          - os: 'macos-latest'
+            python: '3.8'
+            dependencies: 'oldest'
     steps:
     - uses: actions/checkout@v3
       with:
         submodules: "recursive"
-    - name: Set up Python ${{ matrix.config.python }}
+    - name: Set up Python ${{ matrix.python }}
       uses: actions/setup-python@v4
       with:
-        python-version: ${{ matrix.config.python }}
-    - name: Install newest dependencies
+        python-version: ${{ matrix.python }}
+    - name: Get pip cache dir
+      id: pip-cache
       run: |
-        pip install -r requirements/requirements-test.txt
-      if: ${{ matrix.config.dependencies == 'newest' }}
-    - name: Install minimal dependencies
+        echo "dir=$(pip cache dir)" >> $GITHUB_OUTPUT
+    - uses: actions/[email protected]
+      with:
+        path: ${{ steps.pip-cache.outputs.dir }}
+        key: dashboard-unit-test-${{ matrix.os }}-${{ matrix.python }}-${{ matrix.dependencies }}-pip-${{ hashFiles('requirements/requirements-test.txt', '.github/workflows/ci-oldest-reqs.txt') }}
+        restore-keys: |
+          dashboard-unit-test-${{ matrix.os }}-${{ matrix.python }}-${{ matrix.dependencies }}-pip-
+    - name: Install newest dependencies
       run: |
         pip install -r requirements/requirements-test.txt
-      if: ${{ matrix.config.dependencies == 'minimal' }}
+      if: ${{ matrix.dependencies == 'newest' }}
     - name: Install oldest supported dependencies
       # To prevent Dependabot from updating the pinnings in this "oldest"
       # dependency list, we have to avoid the word "requirements" in the
       # filename. That's why it is in the .github/ directory and named "reqs"
       # instead of "requirements."
       run: |
         pip install -r .github/workflows/ci-oldest-reqs.txt
-      if: ${{ matrix.config.dependencies == 'oldest' }}
+      if: ${{ matrix.dependencies == 'oldest' }}
     - name: Install the package
       run: |
         pip install -e .