ui-test-writer

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name:ui-test-writer description: Use when adding, updating, or expanding XCTest UI coverage in the Wikipedia iOS app's WikipediaUITests target. Writes journey-first UI tests with robots, deterministic launch configuration, and fixture-backed defaults.

UI Test Writer

Use this skill to write PR-stable UI tests for WikipediaUITests with minimal boilerplate in each test file.

Required context to load first

1. Read these repository docs before writing code:
   • WikipediaUITests/README.md
   • WikipediaUITests/ROBOTS.md
2. Inspect nearby examples before choosing a pattern:
   • Existing test files in WikipediaUITests/*UITests.swift
   • Existing robots in WikipediaUITests/Robots
   • Configuration for UI test runs:
     • WikipediaUITests/Config/UITestConfiguration.swift
     • WikipediaUITests/Config/UITestLaunchArgument.swift

Core rules

• Write test methods using the Robots pattern documented in WikipediaUITests/ROBOTS.md
• Keep raw XCUIApplication selectors, waits, gestures, screenshots, scrolling, modal handling, and timing details inside robots.
• Prefer one robot per screen or cohesive flow.
• Return the next robot when an action navigates to another screen.
• Use launchWikipediaAppRobot(...) instead of hand-rolling app launch setup.
• Centralize launch state in UITestConfiguration and UITestLaunchArgument; do not set theme, language, onboarding, locale, HTTP profile, or simulator appearance ad hoc in individual tests.
• Default to fixture-backed coverage with fixture-strict; use live networking when E2E is specified.
• Prefer shared accessibility identifiers from AccessibilityIdentifiers.swift over localized visible text.
• STRONGLY prefer targeting elements based their accessibility identifier.
• Assert localized strings only when localization is the behavior under test.
• NEVER XCTSkipUnless / XCTSkipIf unless specifically directed to do so.
• Forward file: StaticString = #filePath and line: UInt = #line through robot assertions so failures point to the calling test.

Minimal test skeleton

When creating a new test file, start from the packaged template:

• UITestFileSkeleton.swift

The skeleton intentionally relies on launchWikipediaAppRobot and existing robots so each new test needs only:

1. A specific test class name.
2. The short robot journey.
3. Small helper methods only when they remove repeated journey setup.

If the journey needs new screen mechanics, add or extend a robot instead of adding selectors to the test. Use this companion template only when a new robot is needed:

• RobotSkeleton.swift

Test Fixtures

Before writing a test, determine if appropriate fixture data is present. If not present, execute the following steps to build out new fixture data:

1. Fixtures are captured from the live Wikipedia/MediaWiki APIs, not synthesized.
2. Reproduce the request the app makes, including the app's iOS User-Agent, Accept, and Accept-Language headers, then save the exact response body under WikipediaUnitTests/Fixtures.
3. Register the route in WikipediaUnitTests/Fixtures/TestNetworkFixtures.json with the request matcher, status, response headers, and bodyResource.
4. Keep payloads byte-for-byte aligned with the API response; when fixture-strict mode hits an unregistered request, it returns a JSON 501 with the exact method and URL to add.

Workflow

1. Clarify the user-visible behavior to cover, the expected result, and whether the scenario can run with fixture-backed networking.
2. Choose where the test belongs:
   • Existing *UITests.swift file for related behavior.
   • New FeatureUITests.swift file only when the coverage is a distinct feature or flow.
3. Adhere to established Robot testing pattern by following examples laid out by existing tests.
4. Add accessibility identifiers to target UI elements
   • Add constants to AccessibilityIdentifiers.swift.
   • Add WMFAccessibilityIdentifier Objective-C bridge values if legacy Objective-C/UIKit code needs them.
   • Wire app code to set the identifier.
5. Add deterministic launch configuration only through UITestConfiguration / UITestLaunchArgument.
6. Validate narrowly:
   • scripts/lint-ui-tests.sh
   • For local validation, prefer the latest installed iOS 26 simulator destination
   • Targeted UI-test run, for example:

xcodebuild test \
  -scheme WikipediaUITests \
  -project Wikipedia.xcodeproj \
  -testPlan UITests \
  -only-test-configuration "English (Light)" \
  -destination "platform=iOS Simulator,name=iPhone 16" \
  -only-testing:WikipediaUITests/<ClassName>/<testName>

For E2E tests:

• run with -only-test-configuration "English (Light, E2E)"
• add the test identifier to WikipediaUITests/E2ESmokeTests.txt to include tests in the E2E smoke lane.