Pure reference catalog for picking a test automation framework - covers Playwright / Cypress / Selenium / WebdriverIO / Appium / Espresso / XCUITest / RestAssured / Karate / k6 / Locust with side-by-side tradeoffs on speed, cross-browser, mobile, parallelisation, language support, ecosystem maturity, CI integration; a decision tree for matching project NFRs to framework choice; and reference directory / fixture / CI layouts for the chosen stack. This is the **upstream selection step**: it decides which tool to adopt, not how to configure a tool already chosen, and not how to rebalance the unit / integration / E2E mix of an existing suite. Use when starting a new test-automation suite from scratch, before installing any tool.
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A team is starting a new test automation suite and needs to pick the stack: framework, runner, assertion library, reporter, CI integration, fixture system, parallelisation strategy, retry policy. Auto-scaffolding the whole framework in one shot is the integration-friction failure mode that dominates AI-in-testing adoption (2025 World Quality Report: 37% of teams). The honest deliverable is decision support, not auto-scaffolding.
This skill is a pure reference: a decision tree + tradeoff matrix the team uses as a checklist. It does not generate framework boilerplate. After the team picks a stack, the per-framework skills (playwright-testing, cypress-testing, etc.) document the configuration; this skill stops at "you picked Playwright + Jest, here's the canonical directory layout to use".
Do not use this skill when:
playwright-testing, cypress-testing, etc.).test-pyramid-balancer.qa-mobile plugin's documentation directly.Six NFR axes drive framework choice. Score each 1 - 5 for the project; rank them by priority. The framework matrix in Step 2 uses these scores.
| NFR axis | Question |
|---|---|
| Cross-browser scope | Is multi-browser execution required? (Chromium-only? + Firefox + WebKit? + IE/Edge legacy?) |
| Mobile scope | Real device + emulator? Hybrid app webview? Native-only? Or web-mobile-viewport only? |
| Team language | What languages do the engineers already know? (Avoiding the framework-language mismatch is the #1 maintenance cost.) |
| Execution speed | Parallel-shard target - minutes for the full suite. CI-cost-driven? |
| Ecosystem maturity | Third-party integrations the team needs (visual regression, accessibility, perf, contract). |
| Hire-ability | Can the team hire engineers familiar with the framework? Smaller frameworks → smaller talent pool. |
| Framework | Cross-browser | Mobile | Language | Speed (parallel) | Ecosystem | Hire-ability | Notes |
|---|---|---|---|---|---|---|---|
| Playwright | Chromium / Firefox / WebKit native, all in one runtime | Mobile-viewport emulation + real device via Playwright Mobile (beta) | TS / JS / Python / .NET / Java | Excellent (auto-parallel, sharding built-in) | Strong (trace viewer, visual snapshots, fixtures, MCP integration) | High (fastest-growing 2024-26) | A common default for greenfield web E2E; its built-in auto-waiting removes the manual-wait flakiness that dominates Selenium suites (Playwright actionability). |
| Cypress | Chromium-family + Firefox + WebKit (newer) | Mobile viewport only; no real-device | JS / TS only | Good (parallel via Cypress Cloud; CLI-parallel limited) | Strong (huge plugin ecosystem) | High | Strong DX for component testing; runs inside-browser limits cross-origin and iframe scenarios. |
| Selenium / WebdriverIO | All browsers via WebDriver protocol | Real device via Appium | All major languages (Java / Python / C# / JS / Ruby) | Moderate (Selenium Grid; WDIO improves on Selenium's runner) | Mature (oldest ecosystem) | Highest (historical talent pool) | Mature but more flake-prone than Playwright: async-wait is the single largest flake category at 45% (Luo et al. 2014), and Selenium leaves that synchronization manual. Migration target, not greenfield default. |
| TestCafe | All browsers; proxy-based (no WebDriver) | Mobile via emulators | JS / TS | Moderate | Smaller ecosystem | Lower | Niche; integrated runner. |
| Puppeteer | Chromium-only natively (Firefox via experimental) | Limited | JS / TS | Good | Smaller than Playwright | Lower | Mostly superseded by Playwright (the team that built Puppeteer started Playwright). |
The 2026-recommendation tree for greenfield web E2E:
| Framework | Platform | Language | Notes |
|---|---|---|---|
| Espresso | Android native | Kotlin / Java | Google's first-party. In-process, fast, deterministic. |
| XCUITest | iOS native | Swift / Obj-C | Apple's first-party. In-process. |
| Appium | iOS + Android (and others) | All major | Cross-platform unifier; trades depth for breadth. WebDriver-based - same flake patterns as Selenium. |
| Detox | React Native | JS / TS | RN-specialist; grey-box testing. |
Decision: if the team is single-platform native (iOS only or Android only), use the first-party framework. Cross-platform → Appium, accept the WebDriver flake-tax. React-Native specifically → Detox.
| Framework | Scope | Language | Notes |
|---|---|---|---|
| RestAssured | REST API integration tests | Java / Kotlin | The JVM-default; mature, deeply integrated with JUnit / TestNG. |
| Karate | REST + SOAP + GraphQL + gRPC | Karate DSL (Cucumber-like) | DSL-first; lowers barrier for non-Java testers. |
| schemathesis | OpenAPI / GraphQL property-based fuzzing | Python | Generative; complements example-based tests. |
| Pact | Consumer-driven contract tests | JS / JVM / Python / Go / Ruby / .NET | Different category - contract, not integration. See pact-contract-testing. |
| Postman / Newman | Collection-driven API tests | Postman DSL | UI-driven authoring; not code-first. Often used by non-engineers. |
| Framework | Scope | Language | Notes |
|---|---|---|---|
| k6 | Load + perf, code-first | JS (with TS support) | Grafana's; lowest barrier for engineers, excellent CI integration. |
| Locust | Load + perf, code-first | Python | Open-source; user-class-based modelling. |
| JMeter | Load + perf, GUI-first | XML config | Mature, ecosystem-heavy; GUI-driven authoring is the trade-off. |
| Gatling | Load + perf, code-first | Scala / Java / Kotlin | High-throughput; JVM stack. |
After the team has chosen a stack, adopt the canonical directory layout the per-framework skill assumes - a convention, not a mandate, but the starting point a newcomer can read. The layouts for Playwright + Jest, Cypress + Mocha, and Selenium / WebdriverIO are in references/directory-layouts.md.
Universal across frameworks:
| Concern | Convention |
|---|---|
| Parallelisation | Shard by file (Playwright --shard=X/Y, Cypress Cloud, WDIO maxInstances). Aim for 5 - 10 minute wall-clock for the full suite per shard. |
| Retries | Retry once on first failure; never retry locally (only CI). Tests retried >1× are flake candidates - triage them. |
| Trace / video | Capture on-first-retry (off for green runs to save storage). Playwright trace: 'on-first-retry' is the default; Cypress + cypress-video-trim similar. |
| Reporting | JUnit XML output for the CI's test-result panel; Allure for human reporting; both via plugin. |
| Secrets | Load from CI secret store (GitHub Actions Secrets, GitLab CI Variables); never commit. |
| Environment matrix | One job per (framework, browser, environment) cell; do not mix in one job. |
The skill recommends deferring framework choice when:
In these cases, the right output is an explicit deferral note: "no decision today; revisit when (a)/(b)/(c) resolves."
| Anti-pattern | Why it fails | Fix |
|---|---|---|
| Picking the framework before the NFRs are scored | Choice driven by hype, not fit; high migration cost when the wrong framework can't deliver. | Step 1 - score the NFRs first. |
| Standardising on one framework across every test layer | Different layers need different tools (Playwright for E2E ≠ k6 for perf ≠ Pact for contract). | Pick per layer; the stack is multiple frameworks. |
| Picking Selenium for greenfield in 2026 | Manual async-wait is the dominant flake category at 45% (Luo et al. 2014), and Selenium does not auto-wait. | Use Playwright for greenfield; reserve Selenium for legacy maintenance. |
| Cross-language teams picking a single-language framework | Engineers can't contribute; suite becomes one person's domain. | Either pick a multi-language framework (Playwright / Selenium) or commit to retraining. |
| Adopting a framework because a contractor used it | Contractor leaves; team can't maintain. | Hire-ability is an NFR. |
| Skipping the directory-layout convention | Every newcomer authoring tests in a different shape; review burden grows. | Step 4 - pick a canonical layout up front, even if you deviate later. |
| Treating this skill as "framework recommender" rather than "decision support" | The skill recommends; the team decides. Automating the decision strips accountability. | The output of this skill is a documented choice, not an automatic install. |
playwright-testing, cypress-testing, selenium-testing, webdriverio-testing).test-pyramid-balancer.playwright-testing, cypress-testing, selenium-testing, webdriverio-testing - downstream per-framework configuration skills.test-pyramid-balancer - layer-mix tuning after the framework is in place.