JUnit tests should fail when application logs error, or possibly warn

[binkley]

Narrative

AS Bob the QA
I WANT JUnit tests to fail when tested code logs ERROR or WARN
SO THAT the application does not run in production with known problems exposed through logging

Business context

• Tracking down real issues in logs is challenging when they are filled with noise
• Errors and warnings logged during development are strong smells, and may expose real issues that need more tests

Acceptance criteria

GIVEN JUnit is testing
WHEN application logs ERROR
THEN current test should fail

GIVEN JUnit is testing
WHEN application logs WARN
THEN current test should fail

[binkley]

Consider creating a JUnit 5 extension for this. References:

• http://www.javamagazine.mozaicreader.com/NovDec2016#&pageSet=25&page=0
• http://junit.org/junit5/docs/current/user-guide/#extensions

[binkley]

Consider a replacement SLF4J logger factory. See http://stackoverflow.com/a/2653919.