As project manager, I would like to convince
higher management to invest more time for development of
unit tests for existing methods. My understanding is that
unit testing is
foundation/pre-req for any meaningful functionality/integration testing and investment into
functional/integration testing without reasonable coverage of unit test would not be wise.
Basically our situation is that after
several years of development, we had nearly
0% of unit test (measured by how much code was covered by test).
2 months after forcing developers into
unit testing, we have like 2% (unit test written only when new method is introduced or when any method is changed). With current rate of work,
it would take ages to cover any reasonable % of methods with unit testing.
Is there any
publication/graph/research/case study, which I can show to them and demonstrate
relationship between probability of introducing hidden regression bug (ie, bug detected by end user and not by unit test) vs
unit test coverage.
I know, that
unit test coverage is bad metric, however is currently best understandable by higher management and I'm in situation, when there is almost no documentation covering
all use-cases/required functionality, where I could match
integration/functional test against