Test Driven Development (TDD) for User Interface (UI) with functional tests

unit-testing tdd functional-testing
Bozho picture Bozho · Jan 11, 2011 · Viewed 13k times · Source

As we know, TDD means "write the test first, and then write the code". And when it comes to unit-testing, this is fine, because you are limited within the "unit".

However when it comes to UI, writing functional tests beforehand makes less sense (to me). This is because the functional tests have to verify a (possibly long) set of functional requirements. This may usually span multiple screens (pages), preconditions like "logged in", "having recently inserted a record", etc.

According to Wikipedia:

Test-driven development is difficult to use in situations where full functional tests are required to determine success or failure. Examples of these are user interfaces, programs that work with databases, and some that depend on specific network configurations.

(Of course, Wikipedia is no "authority", but this sounds very logical.)

So, any thoughts, or better - experience, with functional tests-first for UI, and then code. Does it work? And is it "pain"?

Answer

Boris Pavlović picture Boris Pavlović · Jan 11, 2011

Try BDD, Behavior Driven Development. It promotes writing specification stories which are then executed step by step stimulating the app to change it's state and verify the outcomes.

I use BDD scenarios to write UI code. Business requests are described using BDD stories and then the functionality is being written to turn the stories i.e. tests green.

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