Effective Automated Testing

Agile software development has dramatically changed software construction through the widespread adoption of automated testing and refactoring. There�s more to effective automated testing than simply automating your tests. To achieve maximum benefit, your tests need to satisfy the following goals:

Unambiguous pass/fail: Each test outputs a single bit�pass or fail. No shades of gray, no qualitative output, no interpretation required. Just a simple yes or no.

Self-contained: No setup required before running a test. Before it runs, it sets up whatever environment it needs automatically, and just as important, it undoes any changes to the environment afterward, leaving everything as it found it.

Single-click to run all the tests: All tests can be run in one step without interfering with each other. As with a single test, the output of the complete test suite is a simple pass or fail�pass if every test passes, fail otherwise.

Comprehensive coverage: It�s easy to prove that achieving complete coverage for any nontrivial body of code is prohibitively expensive. But don�t allow that theoretical limitation to put you off�it is possible to achieve close enough to complete coverage as to make no practical difference.

Source of Information :  Paul Butcher - Debug it Find repair and prevent bugs