Which of the following are valid justifications for developers testing their own code during unit testing? (i) Their lack of independence is…

It is unlikely that developers will have a better understanding of the requirements than testers, partly

because testers work closely with the user community (and may be drawn from it) and partly

because developers seldom work with the complete set of requirements in a medium to large

development.

Testers may raise incidents related to the difference between user expectations and the specification,

but these are not unnecessary. Such issues are more likely to arise at the later stages of testing.

Early testing (unit testing) is usually done most effectively by developers with a good understanding

of the code and the development environment; they can be more efficient and more effective at this

level. Later independent stages of testing offset any disadvantage from the lack of independence at

unit testing level.