Stubs in Speclj

2023-06-09

When testing the user interface of a program, one can use stubs to redefine user input to be predetermined.

For testing in Clojure, I use Speclj which allows me to create and test stubs like so:

Add (with-stubs) before using stubs to make sure stub recoding is bound.

(with-stubs)

Then use (with-redefs) to redefine a function to evaluate to whatever you want to simulate the user input to be.

(with-redefs [read-line (stub :read-line {:return "1"})]
  (should= "1" (read-line))
  (should-have-invoked :read-line))

In this case, I redefine the read-line function to evaluate to "1".

Notice that after the test, I add (should-have-invoked :read-line), which just tests if the stub actually worked.