Chapter 5 — GitHub Collaboration

#!/usr/bin/env bash
set -euo pipefail

WORKDIR=$(mktemp -d)
echo "Working directory: $WORKDIR"

# upstream role bare repository
git init --bare -b main "$WORKDIR/upstream.git" -q

# upstream initial
git clone "$WORKDIR/upstream.git" "$WORKDIR/upstream_local" -q
cd "$WORKDIR/upstream_local"
git config user.name "maintainer" && git config user.email "main@example.com"
 git config commit.gpgsign false
echo "# using " > README.md
echo "feature A" > feature_a.py
git add . && git commit -q -m "init: initial commit"
git push origin main -q
echo "upstream initial done"

# contributor fork (= upstream )
git clone "$WORKDIR/upstream.git" "$WORKDIR/my_fork" -q
cd "$WORKDIR/my_fork"
git config user.name "contributor" && git config user.email "contributor@example.com"
git remote add upstream "$WORKDIR/upstream.git"

echo ""
echo "=== fork repository of remote list ==="
git remote -v

# feature branch create (after) work
git switch -c feature/improve-docs
echo "## " >> README.md
echo "1. " >> README.md
git add . && git commit -q -m "docs: add usage section (#1)"

echo ""
echo "=== contributor branch log ==="
git log --oneline --graph --all

echo ""
echo "=== (GitHub UI at PR create) ==="
echo "git push origin feature/improve-docs"
echo "→ GitHub at upstream:main ← origin:feature/improve-docs using PR create"

rm -rf "$WORKDIR"

=== fork simulation ===
upstream → fork → branch → commit → push (to fork)

#!/usr/bin/env bash
set -euo pipefail

WORKDIR=$(mktemp -d)
git init --bare -b main "$WORKDIR/origin.git" -q

git clone "$WORKDIR/origin.git" "$WORKDIR/repo" -q
cd "$WORKDIR/repo"
git config user.name "developer" && git config user.email "dev@example.com"
 git config commit.gpgsign false

echo "# " > README.md
echo "def main(): pass" > app.py
git add . && git commit -q -m "init: project setup"
git push origin main -q

# PR : feature branch → push → merge
git switch -c feature/login
cat >> app.py << 'EOF'

def login(user, password):
 # log 
 return user == "admin"
EOF
git add . && git commit -q -m "feat: implement login function

Closes #3"
git push origin feature/login -q

echo "=== PR branch status ==="
git log --oneline --graph --all

# (after) main using merge (--no-ff using merge commit create)
git switch main
git merge --no-ff feature/login -m "merge: PR#1 — feat: implement login"
git push origin main -q

echo ""
echo "=== PR merge (after) log ==="
git log --oneline --graph

# merge branch cleanup
git branch -d feature/login
git push origin --delete feature/login -q
echo ""
echo "feature/login branch done"

rm -rf "$WORKDIR"

=== PR simulation ===
branch created
commits clean
ready for `gh pr create`

#!/usr/bin/env bash
set -euo pipefail

REPO=$(mktemp -d)
cd "$REPO"
git init -q -b main
git config user.name "developer" && git config user.email "dev@example.com"
 git config commit.gpgsign false

echo "def app(): pass" > app.py
git add . && git commit -q -m "init"

echo "=== Issue commit message ==="
echo ""
echo "Issue #7: log "
echo ""

# fix/issue-7 branch at edit
git switch -c fix/issue-7

cat > app.py << 'EOF'
def login(user, password):
 if not password:
 raise ValueError("Password cannot be empty")
 return True
EOF

git add .
git commit -m "fix: prevent empty password login

- input ValueError 
- add 

Closes #7"

echo "=== commit log ==="
git log --oneline

echo ""
echo "=== commit (before) message ==="
git log -1 --format="%B"

echo ""
echo "=== GitHub UI at of auto ==="
echo "PR commit at 'Closes #7' "
echo "PR merge Issue #7 auto using ."

rm -rf "$REPO"

=== Issue simulation ===
commit message: "fix: handle null input (closes #42)"
on merge → #42 auto-closes

#!/usr/bin/env bash
set -euo pipefail

REPO=$(mktemp -d)
cd "$REPO"
git init -q -b main
git config user.name "admin" && git config user.email "admin@example.com"
 git config commit.gpgsign false

mkdir -p .github/workflows docs src/backend src/frontend

cat > .github/CODEOWNERS << 'EOF'
# CODEOWNERS — PR create auto using .

# : file
* @admin-user

# doc
docs/ @tech-writer @admin-user

# 
src/backend/ @backend-team

# 
src/frontend/ @frontend-team

# CI/CD using — DevOps 
.github/workflows/ @devops-team
EOF

echo "" > src/backend/server.py
echo "" > src/frontend/index.html
echo "doc" > docs/guide.md
echo "Hello" > .github/workflows/ci.yml

git add .
git commit -m "chore: add CODEOWNERS and project skeleton"

echo "=== CODEOWNERS file ==="
cat .github/CODEOWNERS

echo ""
echo "=== repository file ==="
git ls-files

rm -rf "$REPO"

=== CODEOWNERS ===
file written
GitHub will auto-request the matching reviewer on PRs.