test with multiple major versions of pytest

Author: utgwkk

.github/workflows/test.yml

@@ -18,7 +18,24 @@ jobs:
           - '3.7'
           - '3.8'
           - '3.9'
-        # TODO: test with specific major version of pytest
+        pytest-version:
+          - 4
+          - 5
+          - 6
+        exclude:
+          # pytest >= 5.x.x doesn't support Python 2.7
+          - os: ubuntu-latest
+            python-version: 2.7
+            pytest-version: 5
+          - os: ubuntu-latest
+            python-version: 2.7
+            pytest-version: 6
+          - os: windows-latest
+            python-version: 2.7
+            pytest-version: 5
+          - os: windows-latest
+            python-version: 2.7
+            pytest-version: 6
 
     runs-on: ${{ matrix.os }}
 
@@ -41,6 +58,7 @@ jobs:
       run: tox
       env:
         PLATFORM: ${{ matrix.os }}
+        PYTEST_MAJOR_VERSION: ${{ matrix.pytest-version }}
         PYTEST_PLUGINS: pytest_github_actions_annotate_failures
 
   post-test:

tox.ini

@@ -1,5 +1,5 @@
 [tox]
-envlist = py{27,36,37,38,39}-{linux,windows}
+envlist = py{27}-pytest4-{linux,windows}, py{36,37,38,39}-pytest{4,5,6}-{linux,windows}
 
 [gh-actions]
 python =
@@ -14,10 +14,16 @@ PLATFORM =
     ubuntu-latest: linux
     windows-latest: windows
 
+PYTEST_MAJOR_VERSION =
+    4: pytest4
+    5: pytest5
+    6: pytest6
+
 [testenv]
 deps =
-    py27: pytest<5.0.0
-    py{36,37,38,39}: pytest>=5.0.0
+    pytest4: pytest>=4.0.0,<5.0.0
+    pytest5: pytest>=5.0.0,<6.0.0
+    pytest6: pytest>=6.0.0,<7.0.0
 
 commands = {envpython} -m pytest
 passenv = GITHUB_ACTIONS