Maestro Mobile Testing

This skill makes an AI agent write Maestro flows - declarative YAML files that drive iOS and Android apps black-box style with built-in waiting, no test harness compiled into the app, and no WebDriver session management. Trigger it when a repository contains a .maestro/ directory or *.yaml flows with appId: headers, or when the user wants fast, low-maintenance smoke tests for a native, React Native, or Flutter app without the weight of Appium.

Core Principles

1. Maestro waits by default; do not teach it to sleep. Every tapOn and assertVisible polls until the element appears or a timeout expires. Reach for extendedWaitUntil for slow screens; never add fixed delays as a first resort.
2. One flow per user-visible behavior. A flow named checkout-with-saved-card.yaml that does exactly that is debuggable. A 200-line regression.yaml is not. Compose bigger journeys from subflows with runFlow.
3. Select by accessibility id first, visible text second. tapOn: id: "submit-button" survives copy changes and localization; text selectors are acceptable for stable, single-language labels only.
4. Start from a clean, deterministic state. launchApp with clearState: true resets the app between flows; tests that inherit the previous flow's logged-in session fail in random orders.
5. Parameterize with env, not copies. Credentials and hosts go in env: blocks or -e KEY=value CLI arguments so the same flow runs against dev, staging, and CI builds.
6. Treat flows as code. They live in the repo next to the app, run on every PR via emulator CI, and produce JUnit XML that the pipeline understands.

Setup

# Install the Maestro CLI
curl -fsSL "https://get.maestro.mobile.dev" | bash
export PATH="$PATH:$HOME/.maestro/bin"
maestro --version

# Run one flow against the booted simulator/emulator
maestro test .maestro/login.yaml

# Run the whole suite with JUnit output for CI
maestro test .maestro/ --format junit --output maestro-report.xml

# Interactive selector explorer while authoring
maestro studio

Patterns

1. A complete login flow

# .maestro/login.yaml
appId: com.example.shop
env:
  EMAIL: qa@example.com
  PASSWORD: Str0ngPass!
---
- launchApp:
    clearState: true
- tapOn: 'Log in'
- tapOn:
    id: 'email-input'
- inputText: ${EMAIL}
- tapOn:
    id: 'password-input'
- inputText: ${PASSWORD}
- hideKeyboard
- tapOn:
    id: 'login-submit'
- assertVisible: 'Welcome back'
- assertNotVisible: 'Invalid email or password'
- takeScreenshot: logged-in-home

2. Subflows with runFlow: compose journeys, handle one-off dialogs

# .maestro/subflows/login.yaml -- reusable building block
appId: com.example.shop
---
- launchApp:
    clearState: true
- tapOn: 'Log in'
- tapOn:
    id: 'email-input'
- inputText: ${EMAIL}
- tapOn:
    id: 'password-input'
- inputText: ${PASSWORD}
- tapOn:
    id: 'login-submit'
- assertVisible:
    id: 'home-screen'

# .maestro/checkout.yaml -- the journey composes the subflow
appId: com.example.shop
env:
  EMAIL: qa@example.com
  PASSWORD: Str0ngPass!
---
- runFlow: subflows/login.yaml

# Dismiss the push-permission prompt only if it appears
- runFlow:
    when:
      visible: 'Allow notifications?'
    commands:
      - tapOn: 'Allow'

- tapOn: 'Deals'
- scrollUntilVisible:
    element:
      text: 'Wireless Headphones'
    direction: DOWN
    timeout: 20000
- tapOn: 'Wireless Headphones'
- tapOn:
    id: 'add-to-cart'
- tapOn:
    id: 'cart-icon'
- assertVisible: 'Wireless Headphones'
- assertVisible:
    text: 'Checkout'
    enabled: true

3. Waiting, repeats, and assertions with conditions

# .maestro/order-status.yaml
appId: com.example.shop
---
- launchApp
- tapOn:
    id: 'tab-orders'

# Wait up to 15s for async content instead of a blind sleep
- extendedWaitUntil:
    visible:
      id: 'orders-list'
    timeout: 15000

# Pull-to-refresh until the order flips to Shipped, max 5 tries
- repeat:
    while:
      notVisible: 'Shipped'
    times: 5
    commands:
      - swipe:
          direction: DOWN
          duration: 400

- assertVisible:
    text: 'Shipped'
- copyTextFrom:
    id: 'order-number'
- assertTrue: ${maestro.copiedText != ''}

4. CI: Android emulator on GitHub Actions

# .github/workflows/maestro-android.yml
name: maestro-android
on: [pull_request]

jobs:
  flows:
    runs-on: ubuntu-latest
    timeout-minutes: 40
    steps:
      - uses: actions/checkout@v4
      - uses: actions/setup-java@v4
        with:
          distribution: temurin
          java-version: 17
      - name: Build debug APK
        run: ./gradlew assembleDebug
      - name: Install Maestro
        run: |
          curl -fsSL "https://get.maestro.mobile.dev" | bash
          echo "$HOME/.maestro/bin" >> "$GITHUB_PATH"
      - name: Run flows on emulator
        uses: reactivecircus/android-emulator-runner@v2
        with:
          api-level: 34
          arch: x86_64
          profile: pixel_7
          script: |
            adb install app/build/outputs/apk/debug/app-debug.apk
            maestro test .maestro/ --format junit --output maestro-report.xml \
              -e EMAIL=ci-bot@example.com -e PASSWORD="${{ secrets.TEST_USER_PASSWORD }}"
      - name: Publish report
        if: always()
        uses: actions/upload-artifact@v4
        with:
          name: maestro-report
          path: |
            maestro-report.xml
            ~/.maestro/tests

For hosted device execution, the same suite uploads unchanged: maestro cloud --api-key "$MAESTRO_CLOUD_API_KEY" app-debug.apk .maestro/ runs every flow on cloud devices and returns a pass/fail exit code CI can gate on.

Best Practices

• Use maestro studio to discover ids and text before writing selectors by hand; it shows exactly what the accessibility tree exposes.
• Add accessibility identifiers in app code (testID in React Native, accessibilityIdentifier on iOS, contentDescription/resource-id on Android) as part of feature work.
• Keep shared steps in subflows/ and one top-level flow per journey; flows read top to bottom like a manual test script, keep them that readable.
• Tag smoke flows with YAML tags: [smoke] and run maestro test --include-tags smoke on every PR, the full suite nightly.
• Capture takeScreenshot at journey milestones; screenshots plus the JUnit report make CI failures diagnosable without a local repro.
• Pin the emulator API level and profile in CI; device drift is the top source of "passes locally" mysteries.

Anti-Patterns

• Sprinkling - waitForAnimationToEnd and long extendedWaitUntil timeouts everywhere to paper over an app that never settles; fix the spinner, not the test.
• Selecting by index (tapOn: point: 50%,30% or index-based taps) for elements that have ids; coordinate taps break on every screen size.
• One giant flow covering login, browse, checkout, refunds, and settings: a failure at step 40 costs a full re-run to debug.
• Hardcoding production credentials in flow files; use env: plus CI secrets.
• Running flows only on a developer's personal device before release instead of an emulator on every PR.
• Re-implementing Appium-style page objects in JavaScript wrappers around Maestro; the YAML is the abstraction, keep logic out of it.

When to Trigger This Skill

• A repository contains a .maestro/ directory, YAML files starting with appId:, or maestro commands in CI workflows.
• The user wants mobile UI smoke tests with minimal setup, or asks to test a React Native, Flutter, or native app without Appium infrastructure.
• An existing Appium suite is too slow or flaky for PR-level smoke coverage and the team wants a lighter black-box layer on top.
• Mobile onboarding, login, or checkout journeys need regression coverage that designers and QA can read and edit.
• Choose Maestro for declarative cross-platform flows; recommend Detox when the team needs gray-box React Native synchronization, or Appium when tests must script complex logic in a full programming language.