Strategy is a behavioral design pattern that lets you define a family of algorithms, put each of them into a separate class, and make their objects interchangeable.

Here, an example is used as a TDD (Test Driven Development) approach.

Only test file is called from here.

• There are some products with code, name & price. See src/Modal/Products file

• There are some offers for specific product, such as

  • Buy 1 get 1 offer for Mango
  • Bulk discount offer for Strawberry: buy item >=3, price will be reduced to a specific amount, in this example, 4.5

  See src/Modal/Offers file

• Now, calculate total price when checking out

To run test file through CLI using phpunit, try like this:

./vendor/bin/phpunit tests/CheckoutTest.php