Useful automated checks.
WHAT TO TEST FIRST
The paths that matter most Anything involving money Anything that has broken before Authorisation and access control
WHAT MAKES A TEST VALUABLE
It fails when something is genuinely wrong It passes reliably otherwise It is fast It says clearly what broke
WHAT MAKES A TEST WORTHLESS
It fails intermittently for no reason It tests the framework rather than your code It requires constant maintenance for no benefit
WHAT AN INTERMITTENT TEST COSTS
Trust in the whole suite.
People start ignoring failures.
WHAT TO DO ABOUT ONE
Fix it or remove it. Never leave it.
WHAT MAKES TESTS PAINFUL
Dependence on external services Dependence on timing Shared state between tests
WHAT TO DO ABOUT THOSE
Substitute external services Make each test independent Reset state between tests
WHAT NOT TO CHASE
Complete coverage of everything.
WHAT TO AIM FOR
Confidence to deploy without manual checking.
