25Git for SDETs

25.1 Mental model

25.2 Daily workflow commands

# Status / inspection
git status              # what's changed / staged / untracked
git diff                # unstaged changes
git diff --staged       # staged changes
git log --oneline -10   # recent commits
git log --graph --oneline --all

# Start work
git pull --rebase                          # update from remote, rebasing local commits
git checkout -b feature/login-flake-fix    # new branch

# Commit
git add tests/login.spec.ts                # stage specific file
git add -p                                 # stage interactively per hunk
git commit -m "fix flaky login test"

# Push
git push -u origin feature/login-flake-fix

# Update
git fetch origin
git rebase origin/main                     # bring your branch up to date
# (or: git merge origin/main — see "rebase vs merge" below)

25.3 Rebase vs Merge

git checkout feature/x
git merge main

git checkout feature/x
git rebase main

25.4 The PR workflow

# 1. Update main + branch off
git checkout main && git pull
git checkout -b feature/locator-rewrite

# 2. Work, commit small, push
git add . && git commit -m "refactor: replace xpath with getByRole in LoginPage"
git push -u origin feature/locator-rewrite

# 3. Open PR (gh CLI or web)
gh pr create --title "Replace XPath with getByRole" --body "..."

# 4. Address review feedback
git add . && git commit --amend --no-edit
git push --force-with-lease    # safer than --force

# 5. Keep up-to-date with main
git fetch origin && git rebase origin/main
git push --force-with-lease

# 6. Squash on merge (or set repo policy)
# (done in GitHub UI)

25.5 Stash — temporary work-in-progress shelf

git stash             # shove changes aside
git stash list        # see all stashes
git stash pop         # apply latest stash + drop it
git stash apply 1     # apply specific stash, keep it
git stash drop 1      # drop without applying
git stash push -m "WIP login fix" -- tests/login.spec.ts    # partial stash

25.6 Cherry-pick — bring a commit to another branch

git checkout release/v2.3
git cherry-pick abc1234        # apply commit abc1234 to current branch
git cherry-pick abc1234..def5678   # range

25.7 Revert vs Reset vs Restore

25.8 Bisect — find the commit that broke a test

git bisect start
git bisect bad                           # current is broken
git bisect good v1.5.0                   # last known good
# git checks out a midpoint commit
npx playwright test tests/login.spec.ts  # is it broken here?
git bisect good     # or git bisect bad
# Repeat. Git narrows down via binary search.
git bisect reset                         # back to HEAD when done

# Or automate
git bisect run npx playwright test tests/login.spec.ts

25.9 Hooks

.git/hooks/pre-commit       # runs before each commit (lint, type-check, test)
.git/hooks/pre-push         # runs before push (full test suite, build)
.git/hooks/commit-msg       # validate message format (e.g. Conventional Commits)

Use Husky + lint-staged to manage hooks in JS projects:

npm i -D husky lint-staged
npx husky init
# .husky/pre-commit
npx lint-staged

# package.json
"lint-staged": {
  "*.{ts,tsx}": ["eslint --fix", "prettier --write"]
}

25.10 Common SDET scenarios

"I accidentally committed to main"

git branch feature/oops    # save current state to a branch
git reset --hard origin/main  # rewind main locally
git checkout feature/oops  # continue on the new branch

"I committed but forgot a file"

git add forgotten-file.ts
git commit --amend --no-edit
# If already pushed: git push --force-with-lease (only on YOUR branch)

"I want to undo only the last 2 commits but keep my changes"

git reset --soft HEAD~2     # commits gone, changes still staged

"I want to squash 5 commits into 1 before merging"

git rebase -i HEAD~5
# in the editor, change "pick" to "squash" (or "s") on lines 2..5
# save; git lets you edit the combined message

"Someone deleted my work after a force push"

git reflog            # shows every HEAD move including before the force push
git checkout abc1234  # the SHA before the push
git branch recover    # save it

25.11 .gitignore for SDET projects

node_modules/
dist/
build/

# Playwright outputs
playwright-report/
test-results/
blob-report/
allure-results/
.auth/
*.zip

# IDE
.vscode/
.idea/

# Env
.env
.env.local

# OS
.DS_Store
Thumbs.db