alindaByamukama / tddTasks

Simple Multiply, Test First TDD Exercise

• Software Testing with TDD ~ Karl P.

Setup:

1. Create a new node.js project
2. Install and configure a local copy of eslint. Don't install it globally for reasons I mentioned before.
3. Install mocha as a dev dependency
4. Install chai as a dev dependency
5. Create a test directory
6. Create a test.js inside that test directory
7. Create a multiply.js
8. Update npm script to run tests using mocha

Test First TDD Cycle 1

1. Red: Write your first test: assert.equal(multiply(1, 1), 1); in ./test/test.js
2. Red: Run the test. Did it pass? No! Becasue you haven't written the multiply function yet!

Get the test to pass, by writing a multiply function, that is just enough code to pass the test, i.e. function multiply (a, b) { return 1;} 4. Run the test? Does it pass? Should do! Now we are green! 5. Refactor? Probably not necessary!

Test First TDD Cycle 2

1. Red. Write the next test. Run the tests: assertEqual(multiply(2, 2),4)
2. Green: Update multiply() to pass the second test. Make sure the first test still passes too!
3. Do I need to refactor? Nope, its pretty simple

Test First TDD Cycle 3

1. Red. Write the next test: assertEqual(3, 3), 9)
2. Red/Green: Does it pass, maybe, depends on your solution.
3. Green: Update multiply() to pass the third test, if you need to. Make sure you didnt break test 1 or test 2! If you did, fix them.
4. Do I need to refactor? Nope, its pretty simple

Fourth Test Cycle

1. Red. assertEqual(4, 4), 16)
2. Oh! Its green!

Fifth Test Cycle

1. Red: assertEqual(23, 45), 23 * 45)
2. Oh! Its till green!

Yay! Well done! You have completed your first TDD test first code assignment. Time to celebrate 🥳.

Stretch Exercise:

• What might you do if your language didn't natively support multiply?