Injecting Touch Gestures — performTouchInput, Not performGesture

performTouchInput { … } is the single entry point for synthetic touch events in Compose tests. It runs a block in a TouchInjectionScope whose coordinate system is node-local (origin at the node's top-left), batches every event the block enqueues, and flushes them as a single non-recomposing burst when the block returns. The legacy performGesture { … } is @Deprecated("Replaced by performTouchInput") (Actions.kt:337-355) — MUST NOT appear in any new code.

When to use this skill

• The test must simulate a partial gesture, multi-touch, fling with controlled velocity, or pinch-to-zoom — anything richer than a single tap.
• The developer needs precise coordinates relative to a node (e.g. drag by exactly 100 px from center).
• A gesture must be split across two performTouchInput blocks while a finger is still "down".
• A test currently uses performGesture { } and must be migrated.
• A test simulates touch with hardcoded screen coordinates and is flaky on different display sizes.

When NOT to use this skill

• A simple tap on a node — use performClick() from ../clicking-and-scrolling/SKILL.md. It is platform-appropriate and shorter.
• The gesture is a hover, right-click, or scroll wheel — use ../injecting-mouse-and-keyboard/SKILL.md.
• The flow is "tap a button, then assert a Snackbar appears" — assert via ../../assertions/asserting-node-state-and-text/SKILL.md, not by inspecting touch state.
• The test is fighting a fling animation — pause the clock first per ../../synchronization/testing-animations-deterministically/SKILL.md.