Playwright Regression Testing (TypeScript)

Strategy and best practices for automated regression testing of web applications using Playwright with TypeScript.

Activation: This skill is triggered when working with regression test strategy, test suite selection, test prioritization, CI/CD pipeline testing, flaky test management, test sharding, or optimizing test execution for web applications using Playwright.

When to Use This Skill

• Plan regression suites with risk-based and change-based test selection
• Organize tests into tiers (smoke, sanity, selective, full regression)
• Optimize execution with parallelization, sharding, and time-budget strategies
• Integrate with CI/CD using GitHub Actions pipelines
• Manage flaky tests with quarantine, retry policies, and root cause tracking
• Monitor suite health with execution time, flake rate, and detection metrics
• Select tests after changes using git diff analysis and impact mapping

Prerequisites

Requirement	Details
Node.js	v18+ recommended
Playwright	@playwright/test package
TypeScript	typescript configured in project
Browsers	Installed via npx playwright install
Git	Required for change-based test selection
GitHub Actions	Recommended CI/CD platform

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Quick Reference

Tier Model

Tier 0 — Smoke       (< 2 min)   → Critical path, runs on every commit
Tier 1 — Sanity      (< 10 min)  → Core features, runs on every PR
Tier 2 — Selective   (< 30 min)  → Change-based + risk-based, runs on merge
Tier 3 — Full        (< 60 min)  → Complete regression, runs nightly/pre-release

Regression Types

Type	When	Scope
Corrective	No app code changed (infra, config, env)	Full suite to verify nothing broke
Progressive	New features added	Existing tests + new feature tests
Selective	Specific code changes	Changed modules + dependent tests
Complete	Major refactor, release candidate	Run everything across all projects

Tag Taxonomy

Tag	Purpose	Tier
@smoke	Critical path, must always pass	0
@sanity	Core feature verification	1
@regression	Standard regression coverage	2-3
@critical	Revenue/business-critical flows	0-1
@slow	Tests exceeding 30 seconds	3
@quarantine	Known flaky, under investigation	Skipped in CI
@a11y	Accessibility checks	2

CLI Quick Reference

Command	Description
npx playwright test --grep @smoke	Run smoke tier only
npx playwright test --grep @regression	Run regression suite
npx playwright test --grep-invert @quarantine	Skip quarantined tests
npx playwright test --shard=1/4	Run shard 1 of 4
npx playwright test --last-failed	Re-run only failed tests

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Common Rationalizations

Common shortcuts and "good enough" excuses that erode test quality — and the reality behind each.

Rationalization	Reality
"Run all tests every time"	Change-based test selection reduces CI time 60-80%. Run the full suite nightly, not every commit.
"Flaky tests are normal"	Flaky tests erode trust in the entire suite. Quarantine, investigate, and fix them.
"Regression testing is just re-running everything"	Strategic selection (risk-based, change-based) catches more defects in less time than brute-force runs.
"Test sharding is premature optimization"	Parallel sharding cuts CI time linearly with workers. Start with 4 shards from day one.
"Smoke tests cover regression"	Smoke tests verify health; regression tests verify behavior. They serve different purposes.
"Tagging tests is busywork"	Tags enable selective execution, prioritization, and suite analysis. Untagged suites are unmanageable.

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References

Document	Content
Regression Strategy	Tier definitions, test selection (change-based, risk-based, historical, time-budget), directory layout, tagging, naming conventions, Playwright best practices, example test
CI/CD Integration	GitHub Actions tiered pipeline, sharding, merge reports, Playwright config, performance optimization, CLI reference
Flaky Management	Retry policies, quarantine strategies, detection checklist, suite health metrics, troubleshooting

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Verification

After completing this skill's workflow, confirm:

• Regression suite covers critical paths — All priority-1 user flows have regression tests
• Smoke test subset identified — Tagged @smoke tests run in under 2 minutes
• No test duplication — Each scenario tested exactly once at the appropriate level
• Test isolation verified — Running tests in random order produces same results as sequential
• Flaky test baseline established — All tests pass 5/5 consecutive runs
• CI pipeline configured — GitHub Actions workflow runs regression on schedule
• Allure or HTML report generated — Test results available in human-readable format