skills

Building SwiftUI views in Skip projects that work on both iOS and Android. Covers supported components, navigation, state management, Jetpack Compose customization, Material 3 theming, the hard rule against `Image(systemName:)` / `Label(_, systemImage:)` (use `.symbolset` resources via `Image("name", bundle: .module)` instead), and the localization-correct `Label { Text } icon: { Image }` shape.

Start-to-finish orchestrator for building a new cross-platform Skip app. Sequences the other Skip skills in the order you actually need them — scaffold with `skip init`, write SwiftUI, add Material Symbols icons, validate Kotlin transpilation with `swift test`, drive the running app with `skip app launch` + Maestro, localise via `Localizable.xcstrings`, and ship via `skip export` with fastlane metadata. Use this skill at the start of a new project, or when picking up an existing Skip app and trying to decide which skill applies to which phase. Each phase links to the dedicated skill for the deep dive. Also points at the `skipapp-todo` working example at https://github.com/skiptools/skills as a reference build.

Integrating optional Skip frameworks into a project. Covers Firebase, SQLite, Keychain, WebView, audio/video, device sensors, Lottie animations, FFI, and other frameworks. Includes Package.swift dependencies, skip.yml configuration, and usage examples.

Building Skip apps in Fuse mode — Swift compiled natively for Android via the Swift Android SDK (Swift 6.3+), with auto-generated JNI bridging between Swift and Kotlin/Java. Covers when to choose Fuse over Lite, project init with `skip init --native-app`, the `mode: 'native'` + `bridging: true` skip.yml configuration, the `import SkipFuse` requirement for `@Observable` models (a build-time warning, not an error), the internal/public visibility rules for views and properties, the ~60 MB Swift runtime binary cost, debugging via `OSLog.Logger` (breakpoints not yet supported), `ProcessInfo.processInfo.dynamicAndroidContext()` for reaching the Android Context, the Kotlin-inline-class string-interpolation workaround for Android SDK properties, `SKIP_BRIDGE=1` for dynamic library bundling, and the `skip android test` (CLI vs APK mode) test command. Use this skill whenever working on a project whose `skip.yml` contains `mode: 'native'`, or when deciding between Lite and Fuse for a new app.

Swift-to-Kotlin transpilation rules and pitfalls for Skip Lite mode. Covers the high-impact bugs (silent integer overflow, `Double == Int` compile errors, `Foundation.sqrt`, `String.append(Character)`, `Array.remove(atOffsets:)` SwiftUI-only gotcha, variadic init issues, `String(describing:)` and Kotlin map iteration), the `MutableStruct`/`.sref()` value-semantics machinery and the `@nocopy` escape, generics limits and the `@inline(__always)` reified-generics escape, garbage-collection effects (`weak`/`unowned` ignored, `deinit` becomes Kotlin `finalize`), the Kotlish dialect for `#if SKIP` blocks, and the SKIP comment directives (INSERT/REPLACE/DECLARE/NOWARN/SYMBOLFILE/EXTERN/@nocopy/@nodispatch/@bridge). The full long-form rules are in references/swift-kotlin-rules.md. Use when writing or reviewing Swift code in a transpiled Skip project, or when a Kotlin compile error in `XCSkipTests.testSkipModule` points at one of the above patterns.

Creating new Skip app and library projects. Handles skip init commands for both Skip Lite (transpiled) and Skip Fuse (native) modes, adding optional framework dependencies to Package.swift, and scaffolding template code for frameworks like SkipSQL, SkipFirebase, SkipKeychain, SkipWeb, and others.

Exporting, signing, and distributing Skip apps. Covers skip export command, iOS archive and App Store submission, Android APK/AAB signing, ProGuard, app icons, Skip.env metadata, and CI/CD with GitHub Actions.

Writing and running tests in Skip projects. Covers XCTest, Swift Testing, the auto-generated `XCSkipTests` parity harness, the three test runners (`swift test`, `skip android test` CLI mode, `skip android test --apk` mode), the `skip test` parity-report command that produces side-by-side iOS vs. Android results, Robolectric vs. instrumented testing on emulator/device, custom test harness configuration, and diagnosing cross-platform test failures. Use when writing tests, deciding which runner to use, or debugging a Kotlin compile failure in `XCSkipTests.testSkipModule`.

Launching Skip apps on the iOS Simulator and Android emulator simultaneously with `skip app launch`, and driving them with Maestro UI tests. Covers Maestro installation, the canonical edit→launch→eyeball→test inner loop, writing cross-platform flow YAMLs that work on both SwiftUI on iOS and Jetpack Compose on Android, the importance of `.accessibilityIdentifier()` on every interactive view, and the locale-aware screenshot workflow used for fastlane metadata. The platform-by-platform quirk catalog, the iOS/Android locale-switching commands, and the stale-build recoveries are in references/ — link to them rather than re-explaining. Use this skill whenever working on UI tests, manual smoke testing, designing views that need to be drivable by an automated agent, or generating localised App Store / Play screenshots.