Should I write integration test or unit test?

Question

I have a function which saves photos(stored in database,app gives user option to save in a directory) to a given directory.Now, this was not working correctly.I just fixed it.Now, should I write unit test or integration test for the function?

Answer 1

For your case, you want to write an integration test to cover the scenario you mention. I have a full post on this topic. However, here's a summarized version specific to your question:

In his book The Art of Unit Testing, Roy Osherove describes a key principle that a unit test must be “trustworthy”. On the surface, this seems fairly obvious. However, this underlying highlights some of the key differences between a unit test vs an integration test.

With a trustworthy test, you must be able trust the results 100% of the time. If the test fails, you want to be certain that the code is broken and must be fixed. You shouldn’t have to ask things like “Was the database down?”, “Was the connection string OK?”, “Was the stored procedure modified?”. By asking these questions, it shows that you aren't able to trust the results and you likely have a poorly designed “unit test”.

As your scenario describes a situation with similar multiple dependencies, you want to cover it with a integration test. Again, for more details, see my full post here as well.

Good luck!