Pull Requests, Step by Step

# 1. Branch (Lesson 2)
git checkout -b feature/loyalty-discount

# 2. Commit with discipline (Lesson 2)
git add .
git commit -m "Add LoyaltyDiscount implementing DiscountStrategy"

# 3. Push and open a pull request
git push origin feature/loyalty-discount

After pushing, opening a pull request (PR) on GitHub (or your platform of choice) invites review before the change reaches main — the same branch that stayed isolated in Lesson 2 now formally requests to be merged.

## What
Adds a LoyaltyDiscount class implementing DiscountStrategy (SOLID's
Open/Closed principle) for customers with 500+ loyalty points.

## Why
Marketing wants a 15% discount for loyalty program members,
without touching any existing discount logic.

## How to test
1. Create a customer with loyaltyPoints >= 500
2. Apply LoyaltyDiscount to a cart total
3. Confirm the result is 15% off

A good description answers what changed, why, and how a reviewer can verify it — exactly the context a reviewer needs to give a fast, meaningful review instead of guessing at intent from the diff alone.

# after a reviewer requests a change:
git add .
git commit -m "Address review: extract magic number 0.15 into a constant"
git push origin feature/loyalty-discount
# the PR updates automatically with the new commit

Pushing another commit to the same branch updates the existing PR — no need to open a new one. Once every blocking comment (Lesson 5) is resolved and the reviewer approves, the PR merges into main, and the branch has done its job: isolating the work until it was ready to join the shared codebase.