[WIP] feature: fireEvent default event object

src/__tests__/fireEvent.test.tsx

@@ -9,6 +9,7 @@ import {
   TextInput,
 } from 'react-native';
 import { render, fireEvent } from '..';
+import { defaultPressEvent } from '../helpers/create-event';
 
 type OnPressComponentProps = {
   onPress: () => void;
@@ -104,22 +105,33 @@ describe('fireEvent', () => {
   });
 });
 
-test('fireEvent.press', () => {
+test('fireEvent.press with default event', () => {
   const onPressMock = jest.fn();
-  const text = 'Fireevent press';
-  const eventData = {
-    nativeEvent: {
-      pageX: 20,
-      pageY: 30,
-    },
-  };
-  const { getByText } = render(
-    <OnPressComponent onPress={onPressMock} text={text} />
-  );
+  const view = render(<Pressable testID="pressable" onPress={onPressMock} />);
 
-  fireEvent.press(getByText(text), eventData);
+  fireEvent.press(view.getByTestId('pressable'));
+  expect(onPressMock).toHaveBeenCalledWith({ nativeEvent: defaultPressEvent });
+});
 
-  expect(onPressMock).toHaveBeenCalledWith(eventData);
+test('fireEvent.press with default event override', () => {
+  const onPressMock = jest.fn();
+  const view = render(<Pressable testID="pressable" onPress={onPressMock} />);
+
+  fireEvent.press(view.getByTestId('pressable'), { pageX: 10, pageY: 20 });
+  expect(onPressMock).toHaveBeenCalledWith({
+    nativeEvent: { ...defaultPressEvent, pageX: 10, pageY: 20 },
+  });
+});
+
+test('fireEvent.press with explicit event', () => {
+  const onPressMock = jest.fn();
+  const view = render(<Pressable testID="pressable" onPress={onPressMock} />);
+
+  const event = {
+    nativeEvent: { pageX: 20, pageY: 30 },
+  };
+  fireEvent.press(view.getByTestId('pressable'), event);
+  expect(onPressMock).toHaveBeenCalledWith(event);
 });
 
 test('fireEvent.scroll', () => {

src/fireEvent.ts

@@ -3,6 +3,7 @@ import { TextInput } from 'react-native';
 import act from './act';
 import { isHostElement } from './helpers/component-tree';
 import { filterNodeByType } from './helpers/filterNodeByType';
+import { createEvent } from './helpers/create-event';
 
 type EventHandler = (...args: any) => unknown;
 
@@ -69,7 +70,6 @@ const isEventEnabled = (
 const findEventHandler = (
   element: ReactTestInstance,
   eventName: string,
-  callsite?: any,
   nearestTouchResponder?: ReactTestInstance
 ): EventHandler | null => {
   const touchResponder = isTouchResponder(element)
@@ -84,7 +84,7 @@ const findEventHandler = (
     return null;
   }
 
-  return findEventHandler(element.parent, eventName, callsite, touchResponder);
+  return findEventHandler(element.parent, eventName, touchResponder);
 };
 
 const getEventHandler = (
@@ -106,11 +106,9 @@ const getEventHandler = (
 const invokeEvent = (
   element: ReactTestInstance,
   eventName: string,
-  callsite?: any,
   ...data: Array<any>
 ) => {
-  const handler = findEventHandler(element, eventName, callsite);
-
+  const handler = findEventHandler(element, eventName);
   if (!handler) {
     return;
   }
@@ -127,23 +125,61 @@ const invokeEvent = (
 const toEventHandlerName = (eventName: string) =>
   `on${eventName.charAt(0).toUpperCase()}${eventName.slice(1)}`;
 
-const pressHandler = (element: ReactTestInstance, ...data: Array<any>): void =>
-  invokeEvent(element, 'press', pressHandler, ...data);
-const changeTextHandler = (
-  element: ReactTestInstance,
-  ...data: Array<any>
-): void => invokeEvent(element, 'changeText', changeTextHandler, ...data);
-const scrollHandler = (element: ReactTestInstance, ...data: Array<any>): void =>
-  invokeEvent(element, 'scroll', scrollHandler, ...data);
+const getCoreEventName = (eventOrHandlerName: string) => {
+  if (
+    eventOrHandlerName.startsWith('on') &&
+    eventOrHandlerName[2] === eventOrHandlerName[2]?.toUpperCase()
+  ) {
+    const coreName = eventOrHandlerName.slice(2);
+    return coreName.charAt(0).toLowerCase() + coreName.slice(1);
+  }
+
+  return eventOrHandlerName;
+};
 
 const fireEvent = (
   element: ReactTestInstance,
   eventName: string,
-  ...data: Array<any>
-): void => invokeEvent(element, eventName, fireEvent, ...data);
+  ...data: any[]
+): void => invokeEvent(element, eventName, ...data);
 
-fireEvent.press = pressHandler;
-fireEvent.changeText = changeTextHandler;
-fireEvent.scroll = scrollHandler;
+function getEventData(eventName: string, ...data: any[]) {
+  // Legacy mode where user passes 2+ args
+  if (data.length > 1) {
+    return data;
+  }
+
+  // Legacy mode where user passes full event object
+  if (data[0]?.nativeEvent != null) {
+    return [data[0]];
+  }
+
+  // Mode where user passes optional event init data.
+  const name = getCoreEventName(eventName);
+  return [createEvent(name, data[0])];
+}
+
+function invokeEventWithDefaultData(
+  element: ReactTestInstance,
+  eventName: string,
+  ...data: any[]
+) {
+  const eventData = getEventData(eventName, ...data);
+  return invokeEvent(element, eventName, ...eventData);
+}
+
+// Regular events:
+fireEvent.press = (element: ReactTestInstance, ...data: any[]) => {
+  return invokeEventWithDefaultData(element, 'press', ...data);
+};
+
+fireEvent.scroll = (element: ReactTestInstance, ...data: any[]) => {
+  return invokeEventWithDefaultData(element, 'scroll', ...data);
+};
+
+// changeText is not a regular event, as the callback args is just the changed not, and not an Event object
+fireEvent.changeText = (element: ReactTestInstance, text: string) => {
+  return invokeEvent(element, 'changeText', text);
+};
 
 export default fireEvent;

src/helpers/create-event.ts

@@ -0,0 +1,35 @@
+// Based on: https://reactnative.dev/docs/pressevent#example
+export const defaultPressEvent = {
+  changedTouches: [],
+  identifier: 0,
+  locationX: 0,
+  locationY: 0,
+  pageX: 0,
+  pageY: 0,
+  targe: 0,
+  timestamp: 0,
+  touches: [],
+};
+
+// Based on: https://reactnative.dev/docs/scrollview#onscroll
+export const defaultScrollEvent = {
+  contentInset: { bottom: 0, left: 0, right: 0, top: 0 },
+  contentOffset: { x: 0, y: 0 },
+  contentSize: { height: 0, width: 0 },
+  layoutMeasurement: { height: 0, width: 0 },
+  zoomScale: 0,
+};
+
+const eventMap: Record<string, object> = {
+  press: { ...defaultPressEvent },
+  scroll: { ...defaultScrollEvent },
+};
+
+export function createEvent(eventName: string, eventInit?: object) {
+  return {
+    nativeEvent: {
+      ...eventMap[eventName],
+      ...eventInit,
+    },
+  };
+}