Testing and Unit Testing

Ethics Essay: THERAC-25

Review the instructions for the ethics essay today!

Test Your Code

Testing will make you more productive.
Meaning, you will spend less time working on problems because you will

• increase your chances of getting it right the first time AND

• rarely make the same mistake twice.

Warning

• A computer program cannot sufficiently generate test cases for your code.

• The Halting Problem: Alan Turing proved that it is impossible for a computer to determine if any program halts (finishes).
  Watch this explanation video.

  • Optionally, check out this related video: Math's Fundamental Flaw. This video is optional to watch, but fascinating.

• If we don’t know if it halts, how can we test?

• This is your job, and an advantage you have over computation.

Unit Test

• For this course, unit testing is sufficient.

• There are many other forms of testing, but this course focuses on (relatively) small units of code.

• There are numerous unit-testing tools, but no de facto standard for C++.

  • Unlike Java’s JUnit

• Popular testing frameworks for C++ include GoogleTest, Boost.Test, CppUnit, CxxTest, and Catch2.

Doctest – Unit Testing for C++

• We will use Doctest for this course.

  • Doctest is simple, yet has a rich feature set.

• You only need to place the one file, doctest.h, in your test repository.

• I have provided a full template in class-code.
  Let’s take a look

Lab 5

Auto-Grader

• An auto-grader will provide a grade for most of the labs (starting in Lab 5).

  • It will not say what test cases you failed.

  • It may not mention if there is a timeout.

  • It may not say if there are compilation errors.

  • It may tell you which part of the lab you got right or wrong.

• Test cases from the auto-grader will NOT be disclose. You must learn how to write your own test cases!

• The grade from the auto-grader should be pushed to your repository shortly after you push your solution.

Lab 5: A Review of C++ Arrays

Let’s talk about Lab 5.