Test it before it embarrasses you

By the end of this track you will have

1. Step 1One test, written from your own sentence, going red and green on demand.
2. Step 2A habit that turns every bug you find into a test that stops it coming back.
3. Step 3Three tests covering the money, the door and the last thing that broke.
4. Step 4Your three tests will run on every change, without you, and tell you when they go red.
5. Step 5Proof that every test you own can fail, and a habit of re-proving it.

The steps

Each one ends with a check you run yourself. The box is yours to tick when it passes.

1. 1
   Step 1.A test is a sentence about behaviour

   30 minutesOpen to everyone

   Done means

   You break the behaviour deliberately and the test goes red. Change the discount so it returns the full price, then run the suite. You should see the failure and the exact number the test expected. Put the code back and watch it go green. Red on demand, then green. A test that stays green through a broken app is worth nothing.

   The check passed
2. 2
   Step 2.Write the test for the bug you just hit

   25 minutes

   Done means

   The test failed before the fix and passes after it, and you have both outputs in front of you. Then do it once more. Revert the fix, run the whole suite, and confirm that exactly one test goes red and names the bug. One red, everything else green. That is a fence with a hole behind it.

   The check passed
3. 3
   Step 3.The three tests worth having before any others

   45 minutes

   Done means

   All three green, then each one red alone. Delete the permission check and confirm only the access test fails. Put it back, break the payment step, confirm only the money test fails. Three tests, three separate reds, no collateral. If breaking the door turns all three red, your tests are tangled and they will lie to you later.

   The check passed
4. 4
   Step 4.Make it run without you remembering

   40 minutes

   Done means

   You break the app on purpose, on a branch, and let go. Change the price, or delete the permission check from step 3. Push it. Do not open anything, do not run anything, and wait. The run must go red on its own and reach you where you actually read things. Then fix the branch and watch it go green the same way. If you had to go and look, it is not finished.

   The check passed
5. 5
   Step 5.A green suite that tests nothing

   35 minutes

   Done means

   You deliberately break the app so it will not even start. Run the full suite. Rename the entry file, or point the database at nowhere. The correct outcome is a loud failure or an explicit unverified. If the suite comes back green because everything was skipped, you have found the worst defect in your testing. Fix that before you fix anything else.

   The check passed