refactor noxfile by splitting test matrix across two commands

.github/workflows/test.yml

@@ -22,6 +22,8 @@ jobs:
       matrix:
         python-version: ["3.8", "3.9", "3.10", "3.11", "3.12"]
         django-version: ["3.2", "4.2", "5.0", "main"]
+    env:
+      NOX_SESSION: "tests(python='${{ matrix.python-version }}', django='${{ matrix.django-version }}')"
     steps:
       - uses: actions/checkout@v4
 
@@ -36,9 +38,20 @@ jobs:
         run: |
           python -m pip install --upgrade pip nox
 
+      - name: Check if test session exists
+        run: |
+          if nox -l | grep -q "${{ env.NOX_SESSION }}"; then
+            echo "Session exists, proceeding with tests"
+            echo "RUN_TESTS=true" >> $GITHUB_ENV
+          else
+            echo "Session does not exist, skipping tests"
+            echo "RUN_TESTS=false" >> $GITHUB_ENV
+          fi
+
       - name: Run tests
+        if: env.RUN_TESTS == 'true'
         run: |
-          python -m nox --session "tests-${{ matrix.python-version }}(django='${{ matrix.django-version }}')"
+          python -m nox --session "${{ env.NOX_SESSION }}"
 
   tests:
     runs-on: ubuntu-latest

Justfile

@@ -45,7 +45,10 @@ venv PY_VERSION="3.11.5":
 ##################
 
 test:
-    python -m nox --reuse-existing-virtualenvs
+    python -m nox --reuse-existing-virtualenvs --session "test"
+
+testall:
+    python -m nox --reuse-existing-virtualenvs --session "tests"
 
 coverage:
     python -m nox --reuse-existing-virtualenvs --session "coverage"

noxfile.py

@@ -11,43 +11,58 @@
 PY311 = "3.11"
 PY312 = "3.12"
 PY_VERSIONS = [PY38, PY39, PY310, PY311, PY312]
-PY_DEFAULT = PY38
+PY_DEFAULT = PY_VERSIONS[0]
+PY_LATEST = PY_VERSIONS[-1]
 
 DJ32 = "3.2"
 DJ42 = "4.2"
 DJ50 = "5.0"
 DJMAIN = "main"
 DJMAIN_MIN_PY = PY310
 DJ_VERSIONS = [DJ32, DJ42, DJ50, DJMAIN]
-DJ_DEFAULT = DJ32
+DJ_LTS = [DJ32, DJ42]
+DJ_DEFAULT = DJ_LTS[-1]
+DJ_LATEST = DJ_VERSIONS[-2]
 
 
 def version(ver: str) -> tuple[int, ...]:
     """Convert a string version to a tuple of ints, e.g. "3.10" -> (3, 10)"""
     return tuple(map(int, ver.split(".")))
 
 
-def should_skip(python: str, django: str) -> tuple[bool, str | None]:
+def should_skip(python: str, django: str) -> bool:
     """Return True if the test should be skipped"""
     if django == DJMAIN and version(python) < version(DJMAIN_MIN_PY):
-        return True, f"Django {DJMAIN} requires Python {DJMAIN_MIN_PY}+"
+        # Django main requires Python 3.10+
+        return True
 
     if django == DJ32 and version(python) >= version(PY312):
-        return True, f"Django {DJ32} requires Python < {PY312}"
+        # Django 3.2 requires Python < 3.12
+        return True
 
     if django == DJ50 and version(python) < version(PY310):
-        return True, f"Django {DJ50} requires Python {PY310}+"
+        # Django 5.0 requires Python 3.10+
+        return True
 
-    return False, None
+    return False
 
 
-@nox.session(python=PY_VERSIONS)
-@nox.parametrize("django", DJ_VERSIONS)
-def tests(session, django):
-    skip = should_skip(session.python, django)
-    if skip[0]:
-        session.skip(skip[1])
+@nox.session
+def test(session):
+    session.notify(f"tests(python='{PY_DEFAULT}', django='{DJ_DEFAULT}')")
+
 
+@nox.session
+@nox.parametrize(
+    "python,django",
+    [
+        (python, django)
+        for python in PY_VERSIONS
+        for django in DJ_VERSIONS
+        if not should_skip(python, django)
+    ],
+)
+def tests(session, django):
     session.install(".[dev,relay]")
 
     if django == DJMAIN: