Module 4

.travis.yml

@@ -1,8 +1,34 @@
-language: python
-python: 3.6
+language: python            # this works for Linux but is an error on macOS or Windows
+jobs:
+  include:
+    - name: "Python 3.8.0 on Xenial Linux"
+      python: 3.8           # this works for Linux but is ignored on macOS or Windows
+    - name: "Python 3.8.0 on Bionic Linux"
+      python: 3.8
+      dist: bionic
+    - name: "Python 3.7.4 on Xenial Linux"
+      python: 3.7
+    - name: "Python 3.8 dev on Xenial Linux"
+      python: 3.8-dev
+    - name: "Python 3.7.4 on macOS"
+      os: osx
+      osx_image: xcode11.2  # Python 3.7.4 running on macOS 10.14.4
+      language: shell       # 'language: python' is an error on Travis CI macOS
+    - name: "Python 3.8.0 on Windows"
+      os: windows           # Windows 10.0.17134 N/A Build 17134
+      language: shell       # 'language: python' is an error on Travis CI Windows
+      before_install:
+        - choco install python --version 3.8.0
+        - python -m pip install --upgrade pip
+      env: PATH=/c/Python38:/c/Python38/Scripts:$PATH
+  allow_failures:
+    - python: 3.8-dev
 install:
-  - pip install -r requirements.txt
-# command to run tests
+  - pip3 install --upgrade pip  # all three OSes agree about 'pip3'
+  - pip3 install -r requirements.txt
+
+# 'python' points to Python 2.7 on macOS but points to Python 3.8 on Linux and Windows
+# 'python3' is a 'command not found' error on Windows but 'py' works on Windows only
 script:
-  # unit test
-  - python -m pytest -v
+  - python3 -m pytest -v || python -m pytest -v
+