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Add Imperative Gesture Handler Testing API#4309

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Add Imperative Gesture Handler Testing API#4309
coado wants to merge 5 commits into
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@coado/jest-new-api

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@coado

@coado coado commented Jul 9, 2026

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Description

The goal is to make gesture lifecycle tests easier to write when we want to assert application state after each gesture step, without requiring users to manually construct RNGH state events with state, oldState, or handlerTag.

Instead of this lower-level style:

fireGestureHandler(panGesture, [
  { oldState: State.UNDETERMINED, state: State.BEGAN },
  { oldState: State.BEGAN, state: State.ACTIVE },
  { oldState: State.ACTIVE, state: State.END },
]);

tests can now use imperative controller:

const gesture = createGestureController(panGesture);

gesture.begin();
expect(onBegin).toHaveBeenCalled();

gesture.activate();
expect(onActivate).toHaveBeenCalled();

gesture.update({ translationX: 50 });
expect(onUpdate).toHaveBeenCalledWith(
  expect.objectContaining({ translationX: 50 })
);

gesture.end();
expect(onFinalize).toHaveBeenCalledWith(
  expect.objectContaining({ canceled: false })
);

Hook gesture rerenders

Hook-based gestures can be recreated when their callbacks or configuration change during a React rerender while retaining the same handler tag. The controller now resolves the latest registered gesture before every lifecycle operation. This ensures that subsequent steps use the newest callback closures and configuration, including the current enabled value.

For example, if a rerender occurs between begin() and activate(), activate() invokes the callback from the latest render rather than the callback captured when the controller was created.

Reusing a controller for another stream

A controller can now run multiple gesture streams.

After end(), fail(), or cancel(), the terminal state remains available for assertions through getState(). Calling begin() again resets the finished controller internally and starts a new stream.

controller.begin();
controller.activate();
controller.end();

expect(controller.getState()).toBe(State.END);

controller.begin();
expect(controller.getState()).toBe(State.BEGAN);

Test plan

Added tests using new API.

Copilot AI review requested due to automatic review settings July 9, 2026 14:43

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Pull request overview

This PR introduces an imperative testing helper (createGestureController) to simplify gesture lifecycle testing in RNGH Jest utilities, enabling step-by-step state transitions and assertions without manually crafting low-level state/oldState events.

Changes:

  • Added createGestureController, GestureController, and GestureControllerEvent to drive gesture lifecycles imperatively in tests.
  • Exported the new controller API from src/jestUtils/index.ts.
  • Added Jest tests covering lifecycle sequencing, validation, testID resolution, and disabled-gesture behavior.

Reviewed changes

Copilot reviewed 3 out of 3 changed files in this pull request and generated 2 comments.

File Description
packages/react-native-gesture-handler/src/jestUtils/jestUtils.ts Adds the gesture controller implementation and public API surface.
packages/react-native-gesture-handler/src/jestUtils/index.ts Re-exports the controller types and factory function.
packages/react-native-gesture-handler/src/tests/gestureController.test.tsx Adds tests validating the new imperative controller behavior.

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Comment thread packages/react-native-gesture-handler/src/jestUtils/jestUtils.ts
Comment thread packages/react-native-gesture-handler/src/jestUtils/jestUtils.ts
@coado coado marked this pull request as ready for review July 13, 2026 12:38
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2 participants