[thermalctld] Refactor to allow for greater unit test coverage; Add more unit tests (#157)

- Refactor thermalctld to reduce the amount of code in infinite loops, thus allowing us better unit test coverage
- Refactor mock_platform.py such that it inherits from sonic-platform-common in order to ensure it is aligned with the current API definitions (this introduces a test-time dependency on the sonic-platform-common package)
- Increase pytest verbosity to prevent truncation of error messages

- Miscellaneous cleanup:
    - Fixes to grammar
    - Remove unnecessary punctuation from log messages

- Increase overall unit test unit test coverage from 73% to 93%

Author: jleveque

azure-pipelines.yml

@@ -81,8 +81,12 @@ jobs:
           set -xe
           sudo pip2 install swsssdk-2.0.1-py2-none-any.whl
           sudo pip2 install sonic_py_common-1.0-py2-none-any.whl
+          sudo pip2 install sonic_config_engine-1.0-py2-none-any.whl
+          sudo pip2 install sonic_platform_common-1.0-py2-none-any.whl
           sudo pip3 install swsssdk-2.0.1-py3-none-any.whl
           sudo pip3 install sonic_py_common-1.0-py3-none-any.whl
+          sudo pip3 install sonic_config_engine-1.0-py3-none-any.whl
+          sudo pip3 install sonic_platform_common-1.0-py3-none-any.whl
         workingDirectory: $(Pipeline.Workspace)/target/python-wheels/
         displayName: 'Install Python dependencies'
 

sonic-thermalctld/pytest.ini

@@ -1,2 +1,2 @@
 [pytest]
-addopts = --cov=scripts --cov-report html --cov-report term --cov-report xml --junitxml=test-results.xml -v
+addopts = --cov=scripts --cov-report html --cov-report term --cov-report xml --junitxml=test-results.xml -vv

sonic-thermalctld/scripts/thermalctld

@@ -23,7 +23,8 @@
     tests_require=[
         'mock>=2.0.0; python_version < "3.3"',
         'pytest',
-        'pytest-cov'
+        'pytest-cov',
+        'sonic-platform-common'
     ],
     classifiers=[
         'Development Status :: 4 - Beta',