CSC151.01 2006S, Class 19: Unit Testing

Admin:
* I'll leave time at the start of class to discuss questions on exam 1.
* Reminder: No CS extra today.
* Reading for tomorrow "Local Bindings"
* I have no data about the Math study break

Overview:
* Exam 1
* An Overview of Testing.
* Using Our Test Environment.
* Lab.

/Questions on Exam 1/

* See the exam.  Now revised.

/What Did You Learn From The Reading?/

* It's good to test.
* It's good to do a lot of tests.
* Testing by hand is tedious.
* Testing by hand can discourage programmers from changing their code, since looking at the test results is tedious.
* Code that passes a test is not necessarily "good" (correct)
* Testing can be adversarial.

/How To Test/

(load "/home/rebelsky/Web/Courses/CS151/2006F/Examples/unit-test.ss")
(begin-test!)
(test! exp expected)
(test! (+ 2 3) 5)
(test! (+ 2 -2) 0)

/Lab/

One goal of testing: If all the tests succeed, 
  you should be relatively confident that the procedure works
Another goal: Writing tests helps you write the procedure
  (or at least think about what it should do).